Somatom sessions 31

Answers for life in Computed Tomography

SOMATOM Sessions

Issue Number 31 / November 2012 RSNA Edition

Cover Story New Clinical Insights – Faster DiagnosisPage 06

News FAST Dual Energy Boosts Comprehensive Imaging and Treatment in Oncology6

Business We Are FamilyPage 22

Clinical ResultsDiagnosis of Coronary-Vertebral Subclavian Steal Syndrome using iTRIM TechniquePage 34

Science CARE kV Allows a Reduction ofRadiation DosePage 52

2 SOMATOM Sessions · November 2012 · www.siemens.com/healthcare-magazine

Editorial

Cover page: Courtesy of Clinique Pasteur, Toulouse, France

“Due to its broad benefits to the healthcare system, image guided therapy is now a major trend in medicine.

Together with our network of outstanding clinical and industrial partners, we will continue to lead the way in this exciting field.”

Walter Märzendorfer, Chief Executive Officer, Business Unit Computed Tomography and Radiation Oncology, Siemens Healthcare, Forchheim, Germany

SOMATOM Sessions · November 2012 · www.siemens.com/healthcare-magazine 3

Editorial

Dear Reader,

Over the last few years, dose reduction in CT has become a highly considerably issue. The result is that considerably lower dose levels on average are applied to our patients. For some body regions, the improvements are spectacular. Who would have thought 10 years ago, in the early days of cardiac CT, that a coronary CT Angiography would be possible for an adult patient using an effective dose of less than 1 mSv?

At some point we have to ask ourselves whether the battle for the lowest dose makes sense beyond the second digit. Clearly, a 50 or 60% dose reduction is great when you start at 5 or 10 mSv. Yet, below 1 mSv it could be argued that the best possible image quality might be more relevant than another 0.1 mSv in dose reduction. And equally important: even with the latest technologies many examinations still require a couple of mSv in adult patients, e.g. around 3 to 4 mSv for a typical abdomen. So below 1 mSv

might not be the right dose for every patient, too.

We will therefore shift the focus of our efforts in dose reduction – from low dose to right dose. We will advise on absolute dose values whenever possible. We will continue to develop highly innovative dose reduction technologies, such as CARE kV or SAFIRE.1 We will continue to work together with experts, for example in our Siemens Radiation Reduction Alli-ance (SIERRA), to optimize protocols and improve training. However, we will not exclusively promote dose levels of below 1 mSv. Because we believe our patients deserve the right dose for the best possi-ble diagnosis.

We will also release the latest version of syngo.via,2 introducing a wider range of applications and features designed to make reading easier than ever. One example is Bone Reading,2 where images now show the entire spine and rib cage unfolded. In TAVI planning, the all-new syngo.CT Cardiac Function – Valve Pilot2 supports the assessment of the annulus plane.

Finally, we will work to further improve access to state-of-the-art imaging with the SOMATOM® Perspective 64-slice con-figuration. Featuring the latest technolo-gies already introduced to the 128-slice configuration, this scanner includes a footprint of only 18 m2. Its versatility covers single-click reconstruction and labeling of the entire spine through to advanced intervention.3 Our tailored solution for advanced visualization in this segment come with a dedicated set of applications to join the world of syngo.via.

I do hope you enjoy reading more about these topics and catching up on a broad range of clinical and business news in this latest edition of SOMATOM Sessions.

With best regards,

Peter Seitz, Vice President Marketing,

Computed Tomography, Siemens Healthcare, Forchheim, Germany

Peter Seitz

1 In clinical practice, the use of SAFIRE may reduce CT patient dose depending on the clinical task, patient size, anatomical location, and clinical practice. A consultation with a radiologist and a physicist should be made to determine the appropriate dose to obtain diagnostic image quality for the particular clinical task.

2 Under FDA review. Not available for sale in the U.S.3 These features are not commercially available in the

U.S. Due to regulatory reasons their future availability cannot be guaranteed. Please contact your local Siemens organization for further details.


Cover Story

Content

Cover Story

06 New Clinical Insights – Faster Diagnosis

News

12 Precision and Flexibility on Rails16 FAST Dual Energy Boosts Compre-

hensive Imaging and Treatment in Oncology

18 A New Course for CT Scanning Suggested by the Latest Research

20 CARE Right. Committed to the Right Dose in CT

06 syngo.via now fulfills many established computed tomography functions. Whether working on oncological, neurological or cardiac cases, radiologists can save time and may potentially improve the quality of their findings.

18 A New Course for CT Scanning Suggested by the Latest Research

06 New Clinical Insights – Faster Diagnosis

Business

22 We Are Family26 IRIS and Emotion in Daily Practice

Clinical Results

Cardiovascular28 Low Dose CT Scanning with

70 kV in Congenital Heart Disease of a 3-month-old Infant

30 Low Dose CT Diagnosis of Pediatric Aortic Coarctation using CARE kV, SAFIRE and Flash Mode

32 Unroofed Coronary Sinus Syndrome – Diagnosis with Dual Source CT using Flash Mode

34 Diagnosis of Coronary-Vertebral Subclavian Steal Syndrome using iTRIM Technique

Content


Science

44 Research Clusters Enable Transfer of Basic Research to Clinical Routine – Part II. Concentrated Expertise Against Coronary Heart Disease

48 Image Quality in Computed Tomography – Part I. Low Contrast Detectability

52 CARE kV Allows a Reduction of Radiation Dose

Customer Excellence54 Clinical Fellowships: Localized

Learning from the Experts54 ESC Hands-on Tutorials (HoT’s)

Oncology36 Minimally Invasive Treatment

of Hepatocellular Carcinoma using a Siemens Miyabi System

Acute Care38 Aortic Dissection Follow-Up using

Fast Mode with SOMATOM Definition Edge

Orthopedics40 Metal Artifact Reduction by

Energetic Extrapolation in Single Source Dual Energy CT1

42 Metal Artifact Reduction using Dual Energy CT Monoenergetic Imaging

55 New Dual Energy Technology for SOMATOM Definition

55 Flash Imaging – A Book Full of Flash Expertise

56 Frequently Asked Question56 Clinical Workshops 2012/201357 Upcoming Events & Congresses

2012/2013

58 Subscriptions59 Imprint

20 CARE Right. Committed to the Right Dose in CT

52 CARE kV Allows a Reduction of Radiation Dose

Content

1 Under FDA review. Not available for sale in the U.S.


Cover Story

New Clinical Insights – Faster Diagnosissyngo.via now fulfills many established computed tomography (CT) functions. Whether working on oncological, neurological or cardiac cases, radiologists can save time and may potentially improve the quality of their findings.

By Oliver Klaffke

Late on Friday afternoon, and the ground-floor radiology department of the Maussins-Nollet clinic in Paris is alive with activity. Radiologist Catherine Radier, MD, is still on duty in her tiny ground-floor office. Dedicated to her work, she prefers to deal with her patients face-to-face rather than stare endlessly at screens: “Radiology is all about people,” she states. For Radier, any technological advance that allows her to spend more time with her patients is a welcome development. This is precisely why she uses a syngo.via system from Siemens.

“Personally I have benefited greatly from the advances that syngo.via and the CT Oncology Engine have brought to radiology,” Radier says. Both the Siemens SOMATOM® Definition AS and the CT Oncology Engine are in use at her clinic. Thanks to the data pre-processing and retrieval capabilities of these systems, images are instantly available and records are always at hand. In addition, computer-aided detection of lesions has opened up a new diagnostic dimension for the radiologist.

“Personally, I have benefited greatly from the advances that syngo.via and the CT Oncology Engine have brought to radiology.”

Catherine Radier, MD, Radiologist, Maussins-Nollet clinic, Paris, France


Recently, Ms. Radier had the chance to test one of Siemens latest additions: syngo.CT Bone Reading.1 This is an appli-cation designed to support the visual identification of bone metastases or fractures.1 Detecting them in ribs and vertebrae can be a tedious task for radi-ologists: “One can become easily con-fused, wading through stacks of two-dimensional images,” Radier explains.

A palette of oncology functionsThe new application for bone assessment “opens” the entire chest cavity virtually; providing unfolded rib and spine views, so that three dimensions become two, and the whole region is displayed as a single layer. Furthermore, ribs and verte-brae are numbered automatically to aid future reference.Once findings are noted, they are auto-matically remembered by syngo.via’s Findings Navigator and can be easily retrieved. As a core tool, this facility is an

aid to radiologists’ day-to-day work and is particularly useful when they need to share findings with other physicians, “I can easily walk them through a case, going from finding to finding,” Radier explains.Another valuable functionality has been added to syngo.CT Segmentation, which has been designed to segment lesions in the lung, liver, and the lymphatic systems. Advanced Hounsfield Unit Statistics1 are collated to lesions for assessment of hypodense areas of tumors, which might be an indicator of necrosis. These are then color-coded to provide an overview. In addition, volume and percentage compared to complete tumor volume is calculated and displayed. Determining changes in tumor size as well as changes in tumor density is essential both in assessing the progress of the disease, and in evaluating its treatment.The CT Oncology Engine also provides a clear overview of tumor loads and dimensions clearly over time. Thanks to its pre-retrieval function, syngo.PET&CT Cross-Timepoint Evaluation automatically makes existing data available. By show-

ing this in a so called trending table or graph, measurements from up to eight examinations can be compared: “Build-ing such a table takes less than a second,” Radier notes.

Fast access to lifesaving diagnostic information about stroke patientsMeanwhile in northern Germany, an emergency helicopter is landing at Goettingen University Hospital with a patient suffering an acute stroke. Over 1,000 stroke patients are treated here every year: “Our aim is to restore the blood supply to affected tissue as soon as possible,” says neuroradiologist PD Peter Schramm, MD. This is essential if neurological damage is to be kept to a minimum, as up to two million brain cells can be lost every minute following a stroke: time is brain.”

“Three key diagnostic questions are need to be answered in acute stroke: How large are the areas of core infarct and tissue that could potentially be saved (penumbra) with further treatment in

1 Rib and spine assessment are redefined with syngo.CT Bone Reading. Courtesy of Medical University of Vienna, Department of Radiology, Vienna, Austria

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1 The option is pending 510(k) clearance, and is not yet commercially available in the United States.


the brain tissue? Is the stroke caused by bleeding or a clot? And what is the size and location of the clot?” All three ques-tions can be addressed with CT.As the stroke patient is rushed from the helicopter to the radiology unit Schramm turns to his SOMATOM Definition AS+ CT scanner with the CT Neuro Engine. The new perfusion imaging application syngo.CT Neuro Perfusion1 is now avail-able on the thin client-server platform syngo.via. “Treatment without precise knowledge of core infarct size and pen-umbra may do more harm than benefit,” says Schramm. “Therefore, diagnostic imaging tools are required to see the size of the core infarct and penumbra. These need to be able to cover the whole brain, safely, accurately and fast.”“The syngo.CT Neuro Perfusion includes a Tissue at Risk model that is based on the mismatch between blood volume and blood flow,” Schramm says. However, users can also select a custom mismatch, based on user-defined perfusion metrics. Schramm is investigating the Siemens’ unique metric, Time To Drain (TTD), to look for signs of early ischemia. Important, but often overlooked are differences in the hemodynamics of gray vs. white matter: therefore the penumbra analysis can be restricted not only to the affected

scrolling through axial CT Angiography (CTA) source images. However, estimating the size of the clot is somewhat cumber-some and often not possible, since the images are taken at a single point in time. This is where syngo.CT Dynamic Angio comes into play. Dynamic CTA appears to be a solution to this limitation. Movies of blood flow, from arterial to venous phases can be created and temporal Maximum Intensity Projections (tMIP) especially seem to better characterize the clot size due to retrograde collateral filling.“With my SOMATOM Definition AS+ and the CT Neuro Engine, I am able to identify core and penumbra, exclude bleeding and determine the size and location of the clot,“ says Schramm. “Routinely,

“We need a reliable stroke diagnosis within 10 minutes.”

PD Peter Schramm, MD, Neuroradiologist, University Hospital Goettingen, Germany

“Dual Energy opens new dimensions in diagnosis.”

Prof. Michael Lell, MD, Radiologist, University Hospital Erlangen-Nuremberg, Germany

hemisphere. On top of that it can per selection be limited to the brain gray matter. For whole brain perfusion imag-ing, the Adaptive 4D Spiral technology moves the table of the CT smoothly back and forth, providing coverage beyond the width of the detector.The acute therapy varies according to what caused the stroke: thrombolytics need to be administered when a clot is responsible; however, they are contra-indicated when bleeding is the cause. A native head scan will answer the ques-tion “is it bleeding or is it a clot” quickly. Excellent image quality is required here as the subtle nuances indicative of the early signs of ischemic stroke can be difficult to see. “I routinely use Neuro BestContrast,” says Schramm.If the result discovers a clot as the rea-son for the stroke, treatment can include the administration of thrombolytic drugs to dissolve the clot on the one hand and, increasingly, interventional techniques for clot retrieval. “With modern neuro-interventional techniques, such as cath-eters and clot retrieval devices, there’s practically no proximal intracranial artery we can’t open up,” says Schramm. To do this, it is vital to see exactly where the vessel is obliterated. Generally, one can determine the location of the clot by

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patients are ready for stroke intervention in less than 10 minutes. This gives me confidence in better selecting patients that may benefit from interventional stroke treatment,“ concludes Schramm.

Overcome limitations of con-ventional methods“As radiologists we live in exciting times,” says Prof. Michael Lell, MD, radiologist at Erlangen-Nuremberg University Hospital in southern Germany. He has also had the chance to explore some of the new syngo.via applications resulting from the Dual Energy functionality – which, he believes, “opens up new dimensions in diagnosis.”

One of these applications is syngo.CT DE Gout,2 an application that detects the build-up of uric acid crystals: the cause of gout. “We expect an improvement in treatment, as this application will help us differentiate between the apparently similar symptoms of gout and other forms of arthritis,” Lell observes. To date, CT imaging has not been standard proce-dure in the diagnosis of gout. In tradi-tional clinical practice, the presence of increased levels of uric acid and salt crystals in joints has been seen as an indi-cation of gout. However, it is not always so simple. In an acute phase, the levels of uric acid might actually be quite low, giving a false negative reading. Punctur-ing the joints is not always feasible and not always diagnostic. Furthermore, in some gout patients, the crystals only form in the fibres – not the joints. To further complicate matters, the blood levels of uric acid associated with some other arthritic diseases can be as high as those with gout.

2 Infarct (red) and penumbra (yellow) with the tissue at risk model. Courtesy of University Hospital Goettingen, Germany

3 syngo.CT DE Gout color-codes uric acid crystals to easily diagnose gout. Courtesy of Nan Xi Shan Hospital, Guilin, China

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1 The option is pending 510(k) clearance, and is not yet commercially available in the United States.

2 syngo.CT DE Gout is not commercially available in the U.S. Due to regulatory reasons its future availability cannot be guaranteed.


Every year rheumatologists refer between 50 and 100 patients to Lell and his col-leagues for CT examinations: “It is essen-tial to have a reliable way of judging whether the salts are present or not,” he says. This is exactly what syngo.CT DE Gout does, through its ability to clearly show any salt crystals on the CT images.

Bringing clarity to gout diagnosis and treatment“Clear visuals also make communication easier with the patients,” Lell notes. Normally, two-dimensional CT images can leave patients more confused than enlightened; whereas three-dimensional images of a joint – with the salts high-lighted in color – make the situation much clearer.A further advantage of CT scans comes from their ability to assist the physician in assessing the success of gout therapy: “Tracking the presence of uric acid salts with CT over time is a good way of telling whether any improvements have taken place,” says Lell. syngo’s pre-retrieval feature assists with this. Even before a scan has started, any previous images will have been identified and readied for comparison with the most recent findings. “One can then spot easily whether the disease has advanced or not,” Lell adds.In some cases, using Dual Energy can be especially helpful: “Think of uric acid and of calcium pyrophosphate as indicators of different diseases,” says Lell. “With Dual Energy, one can tell them apart. They are marked in different colors; in no time, the radiologist can tell exactly what disease the patient is suffering from.”

Boosting myocardial perfusion analysisAt Innsbruck University Hospital in Austria, matters of the heart are at the core of the daily work of radiologist Gudrun Feuchtner, MD. She performs up to eight coronary CT Angiographies a day: “Time is a precious commodity,” she says. syngo.via is helping her to get more from her images in less time.

Evaluating myocardial perfusion is one of Feuchtner’s regular jobs. She has already been using CT for this task; however, now she has had the chance to test the new features of syngo.CT Cardiac Function. The Enhancement extension shows the perfusion of the heart on an AHA-con-form, 17-segment polar map – it there-fore provides a swift overview of vital details.Looking at perfusion to get an idea of the state of the myocardium has many advantages over simply identifying ste-noses: “With the improved enhancement functionality, I can overcome the short-falls of purely anatomical imaging as it helps me to assess the hemodynamic relevance of a stenosis,” Feuchtner says. With syngo.CT Cardiac Function, she can track physiological changes within the

myocardium, “It is far easier to identify a perfusion defect on a 17-segment map,” she adds.The Hybrid View offers a particularly elegant way of presenting results, by providing a three-dimensional display of the heart. Besides the coronary arteries, it shows an overlay of left ventricular function and perfusion – whether intact or dysfunctional: “The Hybrid View allows a clear judgment of the diseased vessels,” says Feuchtner.In the course of her examinations in Innsbruck Feuchtner gets yet more valu-able information by using syngo.CT Cardiac Function. Besides evaluating first pass enhancement, she also applies the technique of late enhancement imaging to CT. By waiting 6–8 minutes after con-trast agent administration, a second scan

4 The Hybrid View helps to correlate the perfusion defect with the supplying coronary artery. Courtesy of Clinique Pasteur, Toulouse, France

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1 Rapid Results Technology is not commercially available in the U.S. Due to regulatory reasons its future availability cannot be guaranteed.

2 The option is pending 510(k) clearance, and is not yet commercially available in the United States. The statements by Siemens’ customers described herein are based on results that were achieved in the customer’s unique setting. Since there is no “typical” hospital and many variables exist (e.g., hospital size, case mix, level of IT adoption) there can be no guarantee that other customers will achieve the same results.

“It is far easier to identify a perfusion defect on a 17-segment map.”Gudrun Feuchtner, MD, Radiologist, University Hospital Innsbruck, Austria

allows the radiologist to differentiate viable from scarred tissue.[1] Informa-tion about the still-functioning regions of the heart muscle is vital for planning pacemaker surgery. It makes no sense to place electrodes in regions that are no longer working properly. Normally, MRI is used for late enhancement assess-ment, but in certain circumstances it is contra-indicated, e.g. if the patient has a cardiac pacemaker.[2] In these cases, computed tomography may be the method of choice: “syngo.CT Cardiac Function-Enhancement is therefore particularly useful in planning revascu-larisation procedures,” Feuchtner states. “Its images are proving a great help for the cardiac surgeon.”

Saving time in cardiology

Displaying perfusion within the myocardium in this way makes interpretation much easier. Until now, this task demanded considerable amounts of an individual’s time, concentration and endurance. Thanks to the Automatic Pre-processing in syngo.via, all the neces-sary data is now made readily available. “With syngo.via we observe a reduction of read-out time and time-to-diagnosis,” says Feuchtner. By introducing Rapid Results Technology1 Siemens takes image evaluation a step further and combines efficient reading with increased stan-dardization. The generation of images now is not only automated, but also reproducible. The design of individual protocols helps to drive the evaluation of coronary and general vessels and may help to establish a constant quality of care.When it comes to Transcatheter Aortic Valve Implantation (TAVI) planning, syngo.CT Cardiac Function – Valve Pilot2 supports the quantitative assessment of the annulus plane. The annulus plane is displayed and the minimum, maximum, and effective diameters of the aortic annulus are provided as the case is opened.

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Further Information

www.siemens.com/syngo.via

Oliver Klaffke is a science and business writer, who lives in Switzerland and France. Publications for which he has written previously include the New Scientist and Nature, among others.

References[1] Hamilton-Craig C, et al. JACC Cardiovasc Imaging.

2011 Feb; 4(2):207-8.[2] Schroeder S, et al. Eur Heart J. 2008

Feb; 29(4):531-56.


News

Precision and Flexibility on RailsAustria and Japan not only share a passion for classical music. The field of X-ray diagnostics reveals more common ground: clinics in both countries are trailblazers as far as the use of SOMATOM® Definition AS systems with sliding gantry configurations is concerned.

By Regina Sailer, PhD

Be it pain management, tumor therapy, or trauma classification, the SOMATOM Definition AS with Sliding Gantry masters a diverse range of clinical applications, as events in Japan and Austria convincingly disclose. The nascent system has now been put through its paces in both coun-tries, and has been in operation at the Wels Clinic in Grieskirchen, Upper Austria, since February 2012. Experiences of the system in Osaka, where the world’s first SOMATOM Definition AS with Sliding Gantry was installed at the Toyonaka

Municipal Hospital in November 2011, date back even further.

Multiple applications for diagnosis and therapyThe high-end system has created a host of new opportunities for diagnosis and intervention in both countries. The con-ventually-run hospital in Wels demon-strates exactly how clinic resources can be used more effectively as a result. With approximately 1,200 beds, the hospital serves Upper Austria’s entire central

region. The system is deployed primarily in the clinic’s trauma division, concur-rently coping with an additional daily workload of 35 to 50 routine CTs.Senior physician Thomas Muhr, MD, radi-ologist and the clinic’s acting medical director, explains: “A major focus of our clinical activities is CT controlled pain management of the spine.” With over 6,000 cases of intervertebral disk infil-tration annually, Wels leads the national field as far as treatment for this condi-tion is concerned.

“ The resultant precision which can be attained is absolutely phenomenal, and the images are excellent.”

Thomas Muhr, MD, Radiologist and medical director, Wels Clinic in Grieskirchen, Austria


Cardiac examinations are also increasing in frequency at the Wels Clinic, which has a very active cardiac surgery department, gradually becoming part of the hospital’s daily routine. “Here, the CT scanner is currently used chiefly for exclusion diag-nostics and clarification during bypass operations,” Muhr explains. “The resul-tant precision which can be attained is absolutely phenomenal, and the images are excellent,” adds the radiologist. Smaller interventions, including facet joint blocks in the lumbar region, lung punctures, and biopsies are also part of the clinic’s routine. Its proximity to the trauma division results in the system’s additional use in the diagnosis of whiplash injuries, joint injuries, fractures or shoulder injuries, and frequently for CT brain scans. It is also implemented in the examination of

oncology patients during comparative tumor evaluations, for instance. CT-con-trolled radiofrequency therapy is also offered. Although the latter counts as one of the Wels Clinic’s specialist fields, the corresponding case numbers are low, in strong contrast to the situation at Osaka’s 650-bed municipal hospital, where tumor therapy is at the very heart of the SOMATOM Definition AS system’s activities.

Focus on oncological therapy in OsakaAt the Toyonaka Municipal Hospital, the rail-guided SOMATOM Definition AS flexes its muscles primarily in the field of precision oncological therapy. Taku Yasumoto, MD, uses the technology to perform between 50 and 60 interventions on a monthly basis. Barring emergency

procedures, standard examinations include lung biopsies and treatment of hepatocellular carcinomas, which have a high incidence rate in Japan, using radio-frequency ablation (RFA). Yasumoto favors a combined technique of transcatheter arterial chemoembolization (TACE), followed by RFA. Here, the SOMATOM Definition AS with Sliding Gantry is teamed with an AXIOM Artis angiography system from Siemens. Both procedures are performed in a single location on a treatment couch. This saves space, an important factor in Japan. Patients and clinic personnel alike benefit as a result, as TACE plus RFA can now be carried out conveniently without location transfers. During these interventions, imaging quality is particularly crucial. Yasumoto emphasizes that, above all, minimally invasive therapy must be highly selective,

Wels hospital is equipped with a sliding gantry solution designed for use in two rooms, namely in both the trauma room and a second room in which routine CT scans are carried out. Both of these rooms are equipped with a stationary, height-adjustable table. The gantry itself can be moved to any desired position via the rail system.


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and that optimal real-time imaging is absolutely essential in consequence. According to Yasumoto, this is where the scanner comes into its own, offering clear benefits during treatment, as both the needle tips, Lipiodol® and microbubbles can be visualized perfectly with the CT. In addition, the 3D-visualization also helps less experienced personnel with the precise localization of organs and tissue, while, on the other hand, experienced radiologists benefit greatly from the six-image display.

A customized systemThe system in Osaka has been adapted in line with Yasumoto’s specifications in order to function with even greater precision. The screens are now stacked vertically on top of one another on a small trolley and positioned above the board with the joystick. The trolley fits perfectly between CT construction and retracted C-arm, allowing the physician to view the screen and operate the joy-stick with his left hand without having to let go of the needle shaft with his right hand.

Yasumoto has developed two additional special devices to assist him during exam-inations, which he has integrated effec-tively within the existing system. Besides the glove, he uses a personal invention in the shape of a type of cage which surrounds the needle while he holds it. He has also replaced the conventional protective CT shields with a personally designed “Kamakura” (Japanese for “igloo”). This contraption is draped directly over the gantry. The upper section con-sists of leaded crystal, while the lower section forms a lead cover, two milli-meters thick, which protects Yasumoto’s arms and chest while still permitting him to reach through into the gantry’s interior.

One CT for two roomsOsaka Toyonaka Municipal Hospital witnessed the first ever global use of the SOMATOM Definition AS with Sliding Gantry. Although the Wels Clinic was the fifth to be equipped with the system, it is revolutionary in another respect. It was the world’s first hospital to be fitted with a sliding gantry solution designed

for use in two rooms, namely in both the trauma room and a second room in which routine CT scans are carried out. Both of these rooms are equipped with a station-ary, height-adjustable table. The gantry itself can be moved to any desired posi-tion via the rail system serving both rooms with a single click from the control room.This allows the team at Wels to use the CT scanner in both rooms as required, either routinely for “daily business” or for emergency patients in the trauma room. When severely injured individuals are admitted, an event which occurs approx-imately every three days, the lead-lined partition between the adjacent rooms is simply opened, allowing the SOMATOM Definition AS to slide into the emergency area via the rail system, where the patient waits on a special treatment couch equipped with a carbon plate.Both the CT and the diagnostic process can be completed easily and conveniently on this special couch. “A considerable benefit,” explains Thomas Muhr, “as, after conveying the patient from the ambu-lance to the carbon plate, no more trans-fers are required until the time comes to

1 Computed tomography during arterial portography (CTAP) was performed to confirm a hepatocellular carcinoma diagnosis and to aid the physician in deciding on the access path to this challenging tumor location (see also case 5, page 36). Courtesy of Toyonaka Municipal Hospital, Osaka, Japan

2 Polytrauma cases are routine in Wels, Austria. Courtesy of Wels Clinic, Grieskirchen, Austria

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Regina Sailer, PhD, is a communications scientist. She writes for German print and online media as a freelance journalist. Her specialist topics include the fields of medicine, health, new therapies, and research. She lives and works in Salzburg, Austria.

move the individual to a hospital bed.” Up to nine transfers used to be required to complete the diagnostic process. Prob-lems involving obese patients, for whom the old examination table had to be sta-bilized with an extra support, are now also a thing of the past. The new system receives top marks from the team at Wels for both its larger bore and improved hygiene. Muhr comments: “The techni-cally optimized water-cooling system means that we benefit from less patho-gen contamination during interventions and polytrauma. And the reduced heat loss heralds further improvements in energy efficiency.”

Speedy post-processing with syngo.viaThe trauma patients at Wels not only benefit from increased efficacy as far as transport and diagnosis are concerned. In addition, the visualization software syngo.via, which is fully integrated at Wels, facilitates significantly faster CT post-processing in the field of trauma care. Thomas Muhr reports: “syngo.via is a great support, as we can use it to reconstruct images and create 3D-recon-structions in a matter of seconds.” This is particularly advantageous for trauma patients: “We used to require around an hour from the patient’s arrival to the completion of the final image. The new CT has allowed us to reduce this to 35 minutes,” adds the Wels-based radiolo-gist.Not only emergency admissions have been experiencing faster diagnostic procedures since the new equipment’s arrival – oncological patients have also benefited. “We are now in a position to measure tumors and calculate their vol-umes immediately with a simple click. This has simplified things considerably,” explains Muhr, who also underlines the system’s user-friendliness and the advan-tageous impact of automatic preparation on cases.

A giant step forward for patients and colleaguesAll these new options represent a giant step forward for both patients and col-leagues, reports Thomas Muhr, summa-

rizing experiences to date as follows: “It is impossible to rate the acceleration of our work triggered by this new technol-ogy highly enough, particularly in the field of trauma care.” According to Muhr, this progress also goes hand in hand with pleasingly high stability. Downtime is the exception to the rule, despite the system’s novelty. And what happens if the system should malfunction? “In this case, Siemens reacts immediately. The support provided is excellent,” says Muhr. Colleagues at Wels particularly appreci-ate this dedicated service, adds the physi-cian, and are always happy to participate in new projects involving Siemens.The new SOMATOM Definition AS has also established itself as an extremely valuable tool in Japan during its first year in service. According to Yasumoto, the outstanding image quality has success-fully enhanced minimally invasive ther-apy, particularly when combined with ultra-precise table motion.

The trolley allows Taku Yasumoto, MD, to view the screen and operate the joystick with his left hand without having to let go of the needle shaft with his right hand.

www.siemens.com/sliding-gantry

The products/features (here mentioned) are not com-mercially available in all countries. Due to regulatory reasons their future availability cannot be guaranteed. Please contact your local Siemens organization for further details.


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The Institute of Radiology and Nuclear Medicine at the University Medical Center Mannheim, Germany, performs between 100 and 120 CT readings per day. An increasing number of outpatients are sup-plied with telemedical services and tele-radiology, respectively. Six hospitals rely on the comprehensive radiology service during the night, and a smaller satellite hospital uses the entire IT infrastructure for telemedical purposes. Since the insti-tute’s SOMATOM Definition was equipped with FAST Dual Energy about six months

“ Meanwhile I don’t ask myself when to use Dual Source CT with FAST Dual Energy, but rather when not to use it.”

Thomas Henzler, MD, Head of computed tomography at the Institute of Clinical Radiology and Nuclear Medicine at the University Medical Center Mannheim, Germany

ago, its utilization has reached approxi-mately 50% of the Dual Source CT read-ings, with an upward trend.Besides cardiovascular, neurological and trauma readings, the Mannheim Radiology Department provides the entire spectrum of oncological imaging and interventional oncological therapies, e.g. Transcatheter Arterial Chemoemboliza-tion (TACE), Selective Internal Radiation Therapy (SIRT), and Radiofrequency Ablation (RFA). The embedded “Centre of Rare Tumors” focuses on special

FAST Dual Energy Boosts Comprehensive Imaging and Treatment in Oncology

SOMATOM® Definition – Siemens’ first generation Dual Source CT – boosted by FAST Dual Energy now offers valuable functional parameters helping to answer critical oncological questions fast and without increasing radiation dose or contrast media consumption. Specialists at the Institute of Clinical Radiology and Nuclear Medicine at the University Medical Center Mannheim, Germany, appreciate the user-friendly system in their daily imaging and therapy routines.

By Ruth Wissler, MD

tumor entities such as sarcoma and Gastrointestinal Stromal Tumors (GIST).

Oncological challenges in radiology“We are faced with growing requirements from referring oncologists, and we have to supply them with functional parame-ters,” says Thomas Henzler, MD, Head of computed tomography at the Institute of Clinical Radiology and Nuclear Medicine at the University Medical Center Mann-heim, Germany. Increasingly individual-ized diagnostics, personalized interven-tion planning, and therapy monitoring call for sophisticated imaging technolo-gies. Combining Dual Energy CT and MRI with PET-CT provides better functional information.For example, the progress in targeted therapies requires a new quality of ther-apy monitoring. “Functional imaging shows us, that there is imaging beyond Response Evaluation Criteria in Solid Tumors (RECIST),” says Thomas Henzler. “We see that patients receiving targeted therapies live longer, even without reduc-tion of tumor size. So this may partially indicate an improper classification of malignancies if we just use morphological criteria.”The aim is not only to state the presence and the changes in size of tumors during


1 57-year-old patient with large peritoneal GIST metastasis. Low keV monoenergetic iodine maps allowed significantly better assessment of metastatic contrast enhancement, which is an important marker for therapy response evaluation under targeted therapy with Imatinib. Courtesy of University Medical Center Mannheim, Germany

therapy, but also to assess the tumor vascularization or status before and after chemoembolization.

Dual Energy CT provides better functional informationCurrently, a large variety of functional imaging solutions are available. But Dual Energy CT according to Henzler, is prob-ably the most commonly available and cost-efficient imaging method. Dual Energy CT will increasingly gain signifi-cance because medical imaging has to take into account the advantage for the patient as well as the incremental effi-ciency cost ratio. One very important aspect of using SOMATOM Definition with Dual Energy CT is to get functional infor-mation quickly without increasing the radiation dose or the amount of contrast agent. In therapy monitoring, for exam-ple, the low kV monoenergetic selective iodine contrast enhancement allows sig-nificantly better assessment of metastases (see Fig. 1).With an optimal composition of low and high kV data the contrast-to-noise ratio can be improved. This optimal composi-tion is provided with the Dual Energy composition slider included in FAST Dual Energy; consequently the amount of contrast agent used may potentially be optimized. During the last few years the discussion has focussed on reducing the

radiation dose, but not reducing the con-trast agent. “As we found out in a study, dose neutrality can only be confirmed for Dual Source Dual Energy CT,” empha-sizes Henzler.

Clinical advantages: FAST Dual Energy reconstruction

Considerable timesaving is one promi-nent clinical feature. Henzler: “I would assume that for 3D reconstruction, data transmission and storage we can save three to five minutes per case.” During a normal working day this adds up to a considerable acceleration of workflow. This is an important aspect for the tech-nicians, too, because there is no addi-tional workload. The use of FAST Dual Energy right from the start allows generation of additional information such as functional data, if needed, without having to store three times the amount of data, because unused datasets are eliminated and the Picture Archiving and Communication System (PACS) is not ‘jam-packed’. The specialists’ experience with SOMATOM Definition boosted by FAST Dual Energy at the Insti-tute of Clinical Radiology and Nuclear Medicine at the University Medical Center in Mannheim, represents state of the art practice in acceleration of workflow, lean data sets and excellent acceptance by technicians.

1

2 FAST Dual Energy can use statistical information from both images simultane-ously and provides a combined filter for improved mixed images at low and high Dual Energy composition value.

recon part 2

3D recon

FAST Dual Energy image

high kV data

reconpart 1

recon part 1

low kV data

2

Ruth Wissler, MD, studied veterinary and human medicine. She is an expert in science communications and medical writing.


News

A New Course for CT Scanning Suggested by the Latest ResearchTwo recently published scientific studies show how CT scanning might change established guidelines in the case of acute coronary syndrome and in preventive medicine. Siemens SOMATOM® CT scanners are well equipped to set a new course.

By Heidrun Endt, MD


Since the 1970s, when CT became com-mercially available for the first time, it has become a key imaging tool to approach a range of clinical questions. Two large clinical trials have recently been published showing how CT scanning might have an even greater impact and change estab-lished guidelines in the future.

Patient management in the case of acute coronary syndromeThe New England Journal of Medicine, one of the most renowned medical journals, published a multi-center study on the use of coronary CT Angiography (cCTA) examinations in the emergency department. The authors included in their study 1,370 patients who had presented

with suspected acute coronary syndrome. All of these patients had a low to inter-mediate risk of acute coronary syndrome. The patients were then assigned to two groups; one receiving traditional care management as it is performed and estab-lished at the study location, the other receiving cCTA as the initial imaging test. A follow-up was conducted within 30 days of the event. The researchers concluded that cCTA in these patients “[…] appears to allow the safe, expedited discharge from the emergency department of many patients who would otherwise be admit-ted”[1] and that this approach is there-fore “[…] more efficient than traditional care.”[1] Efficient workflow is important, especially in the emergency department. There would clearly not be enough time

to adjust the CT scan protocol manually for each patient. Two studies[2, 3] pub-lished recently evaluated the potential for the use of CARE kV, the automated tube voltage adjustment from Siemens, for cCTA examinations. In both studies, one part of the examinations was carried out with a manually-adjusted tube volt-age based on the BMI of the patient; for the second group of patients CARE kV was used to determine the optimal tube voltage. With CARE kV, the selection of tube voltage resulted in a changed set-ting in 17 out of 38 patients in the first study and the mean CTDIvol decreased from 12.4 mGy to 8.7 mGy.[2] In the second study, Park et al. conclude that they were able “[…] to reduce radiation exposure while maintaining diagnostic

1 CARE kV proposed the use of 80 kV as optimal tube voltage setting for this CT examination of the heart. A 0.7 mSv effective dose was applied for the coronary CT Angiography (Figs. 1A–B). Within their study[2] the authors from Massachusetts General Hospital evaluated the use of CARE kV for this application. Courtesy of Massachusetts General Hospital, Boston, USA

1B1A


2 A 55-year old patient suffering from scleroderma had to undergo a CT exami-nation of the thorax. A lesion in the left upper lobe (arrow, Fig. 2A) was diagnosed as well as lung fibrosis (arrows, Fig. 2B). Due to the use of SAFIRE, the examination could be carried out with an effec-tive dose of 0.35 mSv on the SOMATOM Definition AS 64. The examination was included in the scientific study written by Baumueller et al.[6] Courtesy of University Hospital Zurich, Switzerland

2A 2B

image quality […]”.[3] Further dose reduction can be achieved with iterative reconstruction. An international group of researchers evaluated the use of SAFIRE in an obese patient population for cCTA. Compared with their standard protocol with 120 kV, the low dose protocol with 100 kV and SAFIRE “[…] can reduce the radiation requirements by 50% while maintaining diagnostic image quality in the obese patient population.”[4]

Low-dose CT for persons at high-risk of lung cancerThe New England Journal of Medicine published a large clinical trial with more than 53,000 persons at high-risk of lung cancer.[5] The persons were assigned to one of two groups. Each participant underwent three annual examinations for several years; either with conventional X-ray examination (group 1) or a low-dose CT scan (group 2). Afterwards, there was a follow-up phase that showed that mor-tality from lung cancer was reduced in the low-dose CT scan group.Scanning these persons in a preventive context requires special attention to radiation dose. Baumueller et al. assessed the use of SAFIRE for low dose examina-tions of the lung. The authors conclude that the “radiation dose of non-enhanced lung CT can be lowered to a submilli-sievert level, while image quality still remains diagnostic when data are recon-structed with SAFIRE.”[6] Special organ-sensitive dose protection can be achieved

with X-CARE; here the tube current is lowered for certain angles of the rotation of the X-ray beam. Ketelsen et al. evalu-ated thoracic CT examinations in 30 patients.[7] These patients were given an initial CT scan without X-CARE and had to undergo a second scan as follow-up. For this second examination, X-CARE was used to lower the radiation dose to the female breast and the thyroid gland. Based on their measurements, the authors recommend that X-CARE “[…] should be used in thoracic CT examinations in male and female patients with a possible decrease in organ equivalent doses of sensitive organs by about 30%.”[7]

The impact of these large clinical trialsCardiovascular diseases are on the rise and lung cancer is the most common cause of cancer-related deaths. Conse-quently, research into how to manage these diseases in an optimal fashion is of great importance. Studies such as the two large clinical trials presented above [1, 5] help lead the way to optimized management. Of course, until results find their way into practical guidelines, more studies are needed to further sup-port their findings and subjects need to be looked at from different angles. The technologies implemented in Siemens SOMATOM CT scanners would be of great benefit in both cases: For scanning in the case of suspected acute coronary syn-drome, when there is no time to adjust

References[1] Litt HI, et al. N Engl J Med.

2012 Apr 12;366(15):1393-403.[2] Ghoshhajra BB, et al. Cardiac Computed

Tomography Angiography With Automatic Tube Potential Selection: Effects on Radiation Dose and Image Quality. J Thorac Imaging. 2012 Jul 27. [Epub ahead of print]

[3] Park YJ, et al. J Cardiovasc Comput Tomogr. 2012 May;6(3):184-90.

[4] Wang R, et al. Eur J Radiol. 2012 Nov;81(11):3141-5.

[5] National Lung Screening Trial Research Team. N Engl J Med. 2011 Aug 4;365(5):395-409.

[6] Baumueller S, et al. Low-dose CT of the lung: potential value of iterative reconstructions. Eur Radiol. 2012 Jun 15. [Epub ahead of print]

[7] Ketelsen D, et al. Invest Radiol. 2012 Feb;47(2):148-52.

the protocol for each patient manually; for scanning persons at high-risk of lung cancer in the context of preventive med-icine, where it is especially important to keep the radiation dose low.

News

In clinical practice, the use of SAFIRE may reduce CT patient dose depending on the clinical task, patient size, anatomical location, and clinical practice. A consultation with a radiologist and a physicist should be made to determine the appropriate dose to obtain diagnostic image quality for the particular clinical task. The following test method was used to determine a 54 to 60% dose reduction when using the SAFIRE reconstruction software. Noise, CT numbers, homo-geneity, low-contrast resolution and high contrast resolution were assessed in a Gammex 438 phantom. Low-dose data reconstructed with SAFIRE showed the same image quality compared to full-dose data based on this test. Data on file.


News

The guiding principle in applying radiation is “As Low As Reasonably Achievable”, or ALARA. In computed tomography this means applying not just the lowest, but also the right dose for sound diagnostic imaging. Siemens has, therefore, made a commitment to delivering the right dose in CT with CARE Right. CARE Right sum-marizes Siemens’ efforts in the areas of dose reduction technology, finding the right dose levels for individual exams and managing patient dose throughout the institution.

Right dose technologyIn order to get to the right dose and to reduce it to as low as reasonably achiev-able for the clinical task, the clinical staff need to have the right dose technology. From the beginning of the CT era, devel-oping highly innovative dose reduction technologies was one of Siemens’ main goals. Back in the 1990s, Siemens intro-duced CARE – the Combined Applications to Reduce Exposure. In CT scans, three aspects are crucial: individual size and stature of the patient, examination type,

and, finally, applied radiation dose. They are all the key drivers for the resulting image quality.

Individual patient and exami-nation types

First, the patient’s habitus both in-plane and along the longitudinal axis influences the dose that needs to be applied. Siemens’ CARE Dose4D is unique in adjust-ing modulation in real time during the scan based on only one topogram so that the right dose is always applied accord-

*** Values are based on the default protocols of the SOMATOM Definition Flash with syngo CT 2012B and an average sized patient of 1.75 m and 75 kg*** Iterative Reconstruction is used*** In clinical practice, the use of SAFIRE may reduce CT patient dose depending on the clinical task, patient size, anatomical location, and clinical practice. A consultation with

a radiologist and a physicist should be made to determine the appropriate dose to obtain diagnostic image quality for the particular clinical task. The following test method was used to determine a 54 to 60% dose reduction when using the SAFIRE reconstruction software. Noise, CT numbers, homogenity, low-contast resolution and high contrast resolution were assessed in a Gammex 438 phantom. Low dose data reconstructed with SAFIRE showed the same image quality compared to full dose data based on this test. Data on file.

Reference values Switzerland1 Germany2 European Union3 USA4

Head Routine CTDIvol [mGy] 65 65 60 75

Thorax Routine CTDIvol [mGy] 15 12 30

Abdomen Routine CTDIvol [mGy] 15 20 35 25

Default Siemens Protocol

Standard values* Standard SAFIRE*** values*/**

Study values**

Head Routine CTDIvol [mGy] 59.8 41.4 455

Thorax Routine CTDIvol [mGy] 7.4 4.4 1.56

Abdomen Routine CTDIvol [mGy] 14.2 10.1 6.57

1 Bundesamt für Gesundheit (Merkblatt R-06-06, Diagnostische Referenzwerte in der Computertomographie, 01.04.2010)

2 Bundesamt für Strahlenschutz (Bekanntmachung der aktualisierten diagnostischen Referenzwerte für diagnotische und interventionelle Röntgenuntersuchungen. Vom 22. Juni 2010)

3 European Guidelines on Quality Criteria for Computed Tomography (http://www.drs.dk/guidelines/ct/quality/htmlindex.htm)

4 American College of Radiology (CT Accreditation Program Requirements, Clinical Image Quality Guide, 13.04.2012)

5 Becker HC, et al. Radiation exposure and image quality of normal computed tomography brain images acquired with automated and organ-based tube current modulation multiband filtering and iterative reconstruction. Invest Radiol. 2012 Mar;47(3):202-7.

6 Baumueller S, et al. Low-dose CT of the lung: potential value of iterative reconstructions. Eur Radiol. 2012 Jun 15. [Epub ahead of print] CTDIvol for the protocol using 100 kV.

7 May MS, et al. Dose reduction in abdominal computed tomography: intraindividual comparison of image quality of full-dose standard and half-dose iterative reconstructions with dual-source computed tomography. Invest Radiol. 2011 Jul;46(7):465-70. CTDIvol for abdominal CT calculated according to the conclusion.

Tab. 1: Absolute values which can be obtained with default protocols on the SOMATOM Definition Flash in comparison with reference values from different regions.

CARE Right. Committed to the Right Dose in CTIn CT, achieving reliable clinical results with the greatest patient safety does not mean reducing radiation at all costs. Experts recommend absolute values.

By Ivo Driesser, Computed Tomography, Siemens Healthcare, Forchheim, Germany


ing to the strongly varying attenuation in x-, y- and z-direction during one scan.Second, also the tube voltage should be adapted to the individual patient and examination type. In a CTA, for example, lower kV is beneficial as the contrast media enhanced vessels can be depicted with a better contrast-to-noise-ratio (CNR). However in non-contrast scans or in obese patients higher kV may be better to provide enough power to obtain good and diagnostic image quality. Siemens’ CARE kV is still the only solution on the market that automatically determines the appropriate kV and scan parameters to deliver the right dose for the particular scan and the required image quality.Third, iterative reconstruction approaches proved to be beneficial in reconstructing images of the same diagnostic quality acquired with a lower dose compared to the established filtered backprojection technique. With outstanding clinical results, SAFIRE – Sinogram Affirmed Iterative Reconstruction – enables a dose reduction potential of up to 60%.*** Siemens has also introduced new image reconstruction systems that allow itera-

tive reconstructions of up to 20 images per second, fast enough for clinical routine. As a result, many Siemens sites across the globe use SAFIRE consistently for every examination, even in time crucial environments like acute care.

Absolute dose values – essential for the right doseBut next to having access to the right tech-nology, it is essential to know the right dose levels to perform an examination according to ALARA. There is an ongoing debate about the balance between image quality and amount of radiation. On this issue, Siemens, together with key opinion leaders, founded SIERRA – the Siemens Radiation Reduction Alliance. Feedback from this and other panels of experts provides input for a dedicated development team. That produces the various Siemens protocols needed to comply with the full range of patient types, disease types, examination pro-cedures, and with the expectations of reading physicians with regard to image quality. The result is a sophisticated library of scan protocols focused on apply-

ing the right dose for each examination.In order for users to know, whether they apply the right dose levels, absolute dose values are a pre-requisite. Therefore Siemens provides them along with its pro-tocols and they are confirmed in external peer-reviewed publications (see references 5-7 in Tab.1). Users can apply these val-ues as a reference to compare their cur-rent dose level with regional recommen-dations and with the dose delivered by Siemens CT scanners (see Tab. 1).

Documenting dose – a basis for management, compliance and improvementFinally, organizations need to manage dose across their institutions. Regional regulations sometimes require that radi-ation given to patients is documented. Other CT administrators like to have an overview as a basis for dose optimization. Both cases require structured access to dose data. With DoseMAP – Siemens’ new Dose Management Program – data can be accessed from various sources, such as scanners, PACS or RIS and aggregated to the type of report required. With EduCARE, Siemens also offers specialized trainings focussing on applications to reduce dose. CME-accredited tutorials and webinars can be booked by users for specific topics. Furthermore, Siemens has introduced a new cross-modality consul-tancy program, called Optimize CARE. Siemens professionals work with the customer on site to analyze the current situation, define and implement improve-ment measures to reasonably reduce radiation and then monitor the progress with the customer to finally hit the right dose.

Commitment to the right doseSiemens’ efforts in optimizing dose have also been recognized by others. An impartial organization, KLAS, stated in its report “CT 2011: Focused on Dose” that Siemens was the “leader to catch“, honoring Siemens’ commitment to deliv-ering the right dose.

News

1 Siemens CT updated free-of-charge the SOMATOM Definition AS family for their customers to SAFIRE, the latest evolution in iterative reconstruction. With SAFIRE, it was possible to achieve excellent image quality with a low dose value (CTDIvol:10 mGy).

1


Business

We Are FamilyOnly 12 months after the debut of the SOMATOM® Perspective 128-slice configuration, its sibling is on its way – this time in 64-slice configuration. The SOMATOM Perspective family brings plenty of new features along with its great economics.

By Eric Johnson

The SOMATOM Perspective scanners are ideal for larger private practices and mid-size hospitals, offering them a first step towards the upper-end of computed tomography (CT).“One-size-fits-all has never been the Siemens approach to CT or to medical equipment in general, because we know that requirements vary from clinic to clinic and practice to practice,” comments Florian Belohlavek, Siemens Global Prod-uct Marketing Manager for the SOMATOM Perspective, CT. “So, to meet these needs, we now offer the SOMATOM Perspective

family.” The machines share quite a num-ber of unique functionalities, but differ in their scan coverage capabilities and thus clinical applications. Such is their similarity that customers can buy this 64-slice machine as a starter system from the high-end segment, and in time, upgrade directly to a 128-slice model. The main difference between the two is a matter of clinical performance. The 128-slice has a powerful cardiac and vascular package; the 64-slice addresses custom-ers that only face cardiac questions once in a while and focus on having a strong

workhorse for everyday clinical tasks.The new SOMATOM Perspective was unveiled in November, at the 2012 Radio-logical Society of North America (RSNA) conference, and featured a host of upgraded components. However, one element definitely remains unchanged: the positioning as the most economical CT in its class.

Born this way. So, what’s new?The first new addition to the FAST CARE platform is a feature already available in SOMATOM Definition scanners: FAST Spine.1 This speedier system for recons of the spine is an option for the SOMATOM Perspective family. By preparing ana-tomically aligned reconstruction ranges, as well as the labeling of all acquired vertebrae and discs, FAST Spine1 may potentially reduce time needed for pre-paring spine recons, which is important in time-crucial cases in acute care.Then there is the introduction of tilted spiral scanning2 for analyses of the head and spine. While the previous SOMATOM Perspective offered tilted sequential scan-ning, this now can be done in spiral mode. Also new is i-Control,3 an in-room remote control for interventions. It transfers all scanner controls into the scan room, e.g. for the patient table movement, or remote command for the gantry and scanner functions.Dose protection has been boosted, too. A new password system enables scan pro-tocols to be changed only by authorised people at a practice or clinic, not just by anybody with access to the machine. In addition, the integrated gantry display

Only one year after the debut of the 128-slice SOMATOM Perspective, another is on its way – this time in 64-slice configuration.


1 This case of liver tumor was examined with SOMATOM Perspective. The VRT image highlights multiple liver lesions and fine details of the mesenteric arteries. Courtesy of Diagnosezentrum Favoriten, Vienna, Austria

1

has been upgraded. More information is reported, in a larger format, making it easier to both read and use.4

Practice made perfectAs would be expected in a high-end system, the SOMATOM Perspective family

offers some of the latest innovations in CT. Dose reduction is achieved in three ways. The first of these is through the application of CARE Dose4D, which adapts the X-ray tube current throughout the duration of scan, helping to create images of consistent quality for all organs, patient

shapes, and sizes – in real time. This over-comes the most common challenges of CT imaging: a) the applied dose in ante-rior, posterior, and lateral positions needs to be different; b) each slice requires different dose values’, and c) patients are quite heterogeneous (young/elderly,


Business

small/large), so the applied dose must be adapted to the individual patient; d) patients can move after the initial topogram was acquired, thus a real-time adjustment is needed during the scan.Secondly, iterative reconstruction (IR) further aids dose reduction. Until recently, using IR with CT imaging in conventional clinical medicine was simply too time-consuming: reconstructing images with iterative algorithms required too much computational power. With Sinogram Affirmed Iterative Reconstruction (SAFIRE), Siemens has introduced raw-data-based iterative reconstruction that can achieve a dose reduction of up to 60%5 across a wide range of applica-tions. It also delivers excellent image quality. Due to its reconstruction speed of up to 15 images/second, SOMATOM Perspective brings SAFIRE into the daily routine.The final element of dose reduction

comes from Ultra Fast Ceramic (UFC) detectors, which have already become a key feature in CTs predating the SOMATOM Perspective. UFCs enable the capture of smaller X-ray doses, yet they still respond with high luminance. This means that they outperform conventional detectors, which require more radiation to generate an image of equal quality.Besides this comprehensive dose port-folio, the new scanner also features new functionalities like iTRIM and IVR, improv-ing its diagnostic capabilities. The first, Iterative Temporal Resolution Improve-ment Method (iTRIM) improves temporal resolution, which is essential in cardiac imaging. This novel algorithm analyzes the image for fast moving sections and applies an iterative image reconstruction when required. This supports diagnosis in demanding situations, for example when imaging hearts with rapid move-ments. Interleaved Volume Reconstruction

2 A case of lymphoma – VRT image shows multiple enlarged lymph nodes in the mediastinum and great anatomical details in the lungs. Courtesy of Clinique Sainte Marie, Paris, France

2 (IVR) helps to visualize even very small diagnostic details using a sophisticated reconstruction algorithm.

Taking care of businessMoney, time, space – the SOMATOM Perspective family saves all, which brings down both capital and operating costs.The speed of installation represents a major plus for the SOMATOM Perspective family. Since the scanner and control room have the smallest footprint of any comparable CT system – just 18.5 square meters (199 square feet) – a SOMATOM Perspective will easily fit into the space of an existing CT, with room to spare. It’s also lightweight: tipping the scales at 1,719 kg (3,790 lbs), whereas conven-tional CTs can weigh anything from just over two, to nearly three metric tonnes (4,409-6,613 lbs). Existing CT power sources – rated at 75-150 kVA – can be used because the SOMATOM Perspective requires only 70 kVA. This allows instal-lation in an existing scan room, without the need for extending, floor reinforce-ment or rewiring. All this means that instead of the 3-4 days downtime usu-ally needed to fit a conventional CT, the SOMATOM Perspective can be up and running within 48 hours.In operation, these CTs run at lower temperatures and use less energy. Cool-ing requirements and total electricity consumption are around half those of a conventional scanner. Then comes the masterstroke: eMode. Built into the user interface, eMode allows operation of the scanner in a patient-friendly and finan-cially efficient way – with a single click. An analysis of the scan is made in real time, and the system is instantly fine-tuned according to the requirements of the user. This reduces wear and tear on the sys-tem. Coupled with this it comes a new ‘service plus’ approach from Siemens: for customers who run the SOMATOM Perspective in eMode for more than 80 percent of its operating time, their insti-tution will be rewarded with dedicated eMode service benefits.6

Taking care of people

Of course, money isn’t everything. The SOMATOM Perspective is also simple to


www.siemens.com/ SOMATOM-Perspective

Eric Johnson writes about technology, business and the environment from Zurich. Previously he headed what is now a Thompson-Reuters bureau and corresponded for McGraw-Hill World News.

Both the 64-slice and the 128-slice configuration offer the Illumination Moodlight.

4 The features (here mentioned) are not com-mercially available in the U.S. Due to regulatory reasons their future availability cannot be guaranteed. Please contact your local Siemens organization for further details.

5 In clinical practice, the use of SAFIRE may reduce CT patient dose depending on the clinical task, patient size, anatomical location, and clinical practice. A consultation with a radiologist and a physicist should be made to determine the appropriate dose to obtain diagnostic image quality for the particular clinical task. The follow-ing test method was used to determine a 54 to 60% dose reduction when using the SAFIRE reconstruction software. Noise, CT numbers, homogeneity, low-contrast resolution and high contrast resolution were assessed in a Gammex 438 phantom. Low-dose data reconstructed with SAFIRE showed the same image quality compared to full-dose data based on this test. Data on file.

6 Individual service benefit availability is subject to country-specific offerings.

use. Operators will appreciate ‘ease-your-workday’ accessories such as FAST Planning, FAST Cardio Wizard, the newly introduced FAST Spine,1 Workstream4D, the storage box and a standard recon-struction speed of up to 20 images per second. The gantry also offers Siemens’ unique Illumination MoodlightTM, which helps to banish the sterile, clinical look-and-feel of most examination rooms. As they are so fast and accurate, the scan-ners may allow patients to undergo fewer scans altogether, and during those scans to spend less time holding their breath, rolling or stretching. That is a bonus for patients.So in addition to clinical advancements and significantly reduced overall costs, patients may also benefit from the patient friendly features. This is what makes up

the cumulative strength of this family: It enhances patient care and business.

1 FAST Spine is not commercially available in the U.S. Due to regulatory reasons its future avail-ability cannot be guaranteed.

2 Tilted spiral scanning is not commercially avail-able in the U.S. Due to regulatory reasons its future availability cannot be guaranteed.

3 i-Control is not commercially available in the U.S. Due to regulatory reasons its future avail-ability cannot be guaranteed.


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IRIS and Emotion in Daily Practice

Technical modernization proves particularly challenging for small radiology practices. It is essential to strike the right balance between technical progress, patient expectations, personal aspirations, and costs. Radiologist Christoph Voigt, who runs his own practice based in the Protestant Hospital in Hattingen, Germany, is well on track with the Siemens package, consisting of SOMATOM® Emotion and IRIS.

By Ingrid Horn, PhD

“Back then, when the issue of a new CT system cropped up, we decided on an ideal combination,” says Christoph Voigt. A SOMATOM Emotion 16 scanner, an unpretentious yet high-quality computed tomography scanner from Siemens, has graced his practice since March 2012. The most popular model in the compact class is equipped with the high-perfor-mance Ultra Fast Ceramic (UFC) detector technology. As a result, the SOMATOM Emotion generates premium-quality images while helping to minimize radia-

tion exposure for patients. However, Christoph Voigt, who had prior experi-ence of Siemens’ CT technology, decided to go a step further in the knowledge that appropriate image reconstruction methods can produce an additional reduction in patient dose. The Hattingen-based radiologist chanced upon IRIS while researching this topic. “Iterative Reconstruction in Image Space” success-fully reduces image noise to such an extent that the radiation dose used to generate the images can be decreased

significantly without impairing image quality. In the meantime, many CT models produced by Siemens can be upgraded with iterative reconstruction. Christoph Voigt explains his decision as follows: “We wanted to purchase a reli-able, modern and economically efficient device with genuinely good prospects.”

Raised competitive profileIRIS is en vogue. The radiologist and his partners are aware that following current trends is key to remaining competitive.

The team at the Protestant Hospital in Hattingen, Germany, is proud to work with SOMATOM Emotion in combination with IRIS. Main tasks include colonographies, tumor and nervous system imaging.


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Hattingen lies on the periphery of the Wuppertal conurbation in the German federal state of North Rhine-Westphalia. The practice owners decided to invest in IRIS to raise their competitive profile and set themselves apart from other radiol-ogy institutions. Above all, it is a way to counteract patient migration to radiol-ogy centers. As a result, they spread the good news of their practice’s technical upgrade via local newspaper. And atten-tion was certainly paid by patients. As Christoph Voigt discovered during ensu-ing discussions, the dose reduction facil-itated by IRIS was the most important aspect in their eyes. Meanwhile, he has realized exactly how much the SOMATOM Emotion and IRIS combination achieves. When compared to his previous images and external images of patients, he puts the average dose savings at 50%.1

Dose reduction as top priorityPatients at the joint practice are referred by both local practitioners and the hos-pital. Approximately 25 patients with a wide range of clinical diagnoses receive CT scans daily. Christoph Voigt explains: “We do everything the device permits with the exception of cardiac CTs.” Appli-cations in focus include colonographies and tumor and nervous system imaging. Voigt places great emphasis on an opti-mized balance of image quality and radi-ation dose. In some cases, such as muscle-skeletal system imaging, he retains the conventional dose in order to benefit from increased image quality with IRIS. In general, however, dose reduction is the top priority. Voigt says: “This method is particularly beneficial for young people with testicular carcinomas or lymphomas, as the total radiation load in the face of the frequent checkups decreases.” The thorax CT of a patient suffering from a bronchial carcinoma convincingly dem-onstrates the way in which outstanding images can be achieved with a reduced radiation dose and via the use of IRIS. Although the radiation load is just as high as in the case of the two-plane X-ray, the CT provides more information than the classic radiograph, which may aid the physician in making decisions regarding possible surgical interventions. As a result,

www.healthcare.siemens.com/computed-tomography/ clinical-applications/iris

paranasal sinuses are only scanned with the CT scanner and IRIS technology in Hattingen.Christoph Voigt believes that his practice now provides standard examinations at university level thanks to the new device configuration. He is equally impressed by the fact that, after just a brief famil-iarization phase, the use of IRIS and the interpretation of the resultant images have quickly become routine. IRIS is always an asset in the eyes of Christoph Voigt, whether a small radiology prac-tice is debating a new acquisition or an upgrade.

1 Thorax CT of a patient suffering from a bronchial carcinoma. Courtesy of RSN Hattingen, Germany

1

Ingrid Horn, PhD, studied biology and biochemistry. She is an expert in science com-munications and an experienced medical writer with an emphasis on biomedical topics in fields including medical engineering, neuroscience, oncology, and pediatrics.

1 In clinical practice, the use of IRIS may reduce CT patient dose depending on the clinical task, patient size, anatomical location, and clinical practice. A consultation with a radiologist and a physicist should be made to determine the appropriate dose to obtain diagnostic image quality for the particular clinical task. The following test method was used to determine a up to 60% dose reduction when using the IRIS recon-struction software. Noise, CT numbers, homo-geneity, low-contrast resolution and high contrast resolution were assessed in a Gammex 438 phantom. Low-dose data reconstructed with SAFIRE showed the same image quality compared to full-dose data based on this test. Data on file.

The statements by Siemens’ customers described herein are based on results that were achieved in the customer’s unique setting. Since there is no “typical“ hospital and many variables exist (e.g., hospital size, case mix, level of IT adoption) there can be no guarantee that other customers will achieve the same results.


Clinical Results Cardiovascular

HISTORY

A 3-month-old male infant was admitted with central cyanosis and a heart murmur. An echocardiography revealed complex cyanotic heart disease (situs inversus, dextrocardia, tricuspid atresia, univentric-ular heart and pulmonary atresia). The pulmonary artery anatomy could not be clearly delineated in echocardiography.

DIAGNOSIS

A CT Angiography (CTA) revealed a confluent central pulmonary artery, uni-focally supplied by a ductus arteriosus (Figs. 1–3, arrows). The ductus arteriosus originated from the descending aorta and ran a tortuous S-shape course before inserting into the right pulmonary artery. There was a long segment narrowing of the proximal right pulmonary artery (Fig. 3, dashed arrow) between the pul-

Case 1 Low Dose CT Scanning with 70 kV in Congenital Heart Disease of a 3-month-old InfantBy Martin Wong,* Wai Leng Chin**

** Paediatric Cardiology Unit, Pusat Jantung Hospital Umum Sarawak, Malaysia** Siemens Healthcare, Regional RHQ, Singapore

monary artery confluence and the ductal insertion site. Otherwise, both distal pulmonary arteries were of average size. The univentricular heart (Fig. 4, asterix) and dextrocardia were also seen in the CTA.The infant successfully underwent a left modified Blalock-Taussig shunt as the first step in the single ventricle repair pathway.

1 2


ExAMINATION PROTOCOL

Scanner SOMATOM Definition Flash

Scan area Thorax

Scan length 147 mm

Scan direction Cranio-caudal

Scan time 0.35 s

Tube voltage 70 kV

Tube current 132 eff. mAs

Dose modulation

CARE Dose4D

CTDIvol 1.29 mGy

DLP 19 mGy cm

Rotation time

0.28 s

Pitch 2.0

Slice collimation 0.6 mm

Slice width 0.6 mm

Spatial Resolution

0.33 mm

Reconstruction increment

0.4 mm

Reconstruction kernel

B26

Contrast

Volume 8 mL

Flow rate 1.0 mL/s

Start delay CARE Bolus

Cardiovascular Clinical Results

COMMENTS

70 kV CTA clearly demonstrated the complex pulmonary artery anatomy and enabled a prompt diagnosis and pre-operative planning. Invasive cardiac catheterization became unnecessary.The combined effect of the low kilo- voltage setting of 70 kV and the auto-

4 Thin MIP 10 mm shows univentricular heart (asterix), and dextrocardia.

4

*

matic tube current dose modulation for low radiation dose is feasible in small-size pediatric patients, without impairing image quality.

31–3 VRT (Fig. 1),

thin MIP 7 mm (Fig. 2) and 5 mm (Fig. 3) images show a confluent central pulmonary artery, unifocally supplied by a ductus arteriosus (Figs. 1–3, arrows). The ductus arteriosus originated from the descending aorta and ran a tortuous S-shape course before inserting into the right pulmonary artery. A long seg-ment narrowing of the right pulmonary artery (Fig. 3, dashed arrow) could also be visualized between the pulmonary artery confluence and the ductal insertion site.



HISTORYA 4-year-old boy was presented with a history of hypertension. A physical exam-ination revealed upper extremity hyper-tension and diminished femoral pulses. A systolic ejection murmur, at the left upper sternal border, radiated to the interscapular area. A cardiovascular CT examination was requested to evaluate the aortic anatomy prior to surgery.

DIAGNOSIS

A thoracic CT Angiography (CTA) scan with ECG triggering confirmed the coarctation of the aorta (Figs. 3, 5-8). The coarctation was distal to the left subclavian artery and measured 15 mm in diameter proximal to the obstruction, 5 mm at the smallest diameter, 16 mm distal to the obstruction and 10 mm in length. Additionally, a small patent ductus arteriosus (Figs. 4, 7-8) was found, connecting the main pulmo-nary artery and the upper descending aorta. The cardiac structures, as well as the origins and the courses of the coro-nary arteries, showed no abnormalities.

COMMENTS

Flash Mode enables an ECG-triggered spiral scan starting at 10% of the R-R inter-val with a high pitch of 3.4. The heart rate

Case 2 Low Dose CT Diagnosis of Pediatric Aortic Coarctation using CARE kV, SAFIRE and Flash ModeBy Pei Nie, MD,* ximing Wang, MD,* Zhaoping Cheng, MD,* Yanhua Duan, MD,* xiaopeng Ji, MD,* Jiuhong Chen, MD, PhD**

** Shandong provincial key laboratory of diagnosis and treatment of cardio-cerebral vascular diseases, Shandong Medical Imaging Research Institute, Shandong University, Jinan, Shandong, P. R. China

** CT Research Collaboration, Siemens Ltd. China, Beijing, P. R. China

1 Flash Mode enables data acquisition within one cardiac cycle.

2 The parameters of CT scanning and contrast injection were recorded in the patient protocol.

1

2



Scanner SOMATOM

Definition Flash

Scan area Thorax

Scan length 144 mm

Scan direction Caudo-cranial

Scan time 0.32 s

Tube voltage 70 kV with CARE kV


Dose modulation CARE Dose4D

CTDIvol 0.37 mGy

DLP 8 mGy cm

Effective dose 0.35 mSv

Rotation time 0.28 s

Pitch 3.4

Slice collimation 128 x 0.6 mm

Slice width 0.75 mm

Spatial Resolution 0.33 mm


0.5 mm


I26f, SAFIRE

Heart rate 78 – 100 bpm

Contrast350 mg/mL, Ultravist, Iopromide

Volume18 mL (contrast) + 15 mL (saline)

Flow rate 1.5 mL/s

Start delay 25 s

varied between 78 to 100 bpm (Fig. 1), however, the image acquisition of the entire thorax was completed within one cardiac cycle in only 0.46 s. Therefore neither sedation nor breathhold was necessary. A combination of various techniques was applied to lower the radiation dose to 0.35 mSv – CARE Dose4D (automatic tube current modulation), CARE kV (auto-matic tube voltage optimization) and SAFIRE (raw data-based iterative recon-struction).The amount of contrast medium used could also be reduced to 18 mL (1.2 mL per kg body weight) – thanks to the Flash scanning speed and the intensive enhancement achieved at 70 kV.

3–8 Maximum Intensity Projection (MIP) images (Figs. 3–4) and volume-rendered images (Figs. 5–8) demonstrated the coarctation of the aorta (arrows) and the patent ductus arteriosus (dashed arrows) between the main pulmonary artery and the upper descending aorta.

3 4

7

5

8

6

Cardiovascular Clinical Results

In clinical practice, the use of SAFIRE may reduce CT patient dose depending on the clinical task, patient size, anatomical location, and clinical practice. A consultation with a radiologist and a physicist should be made to determine the appropriate dose to obtain diagnostic image quality for the particular clinical task. The following test method was used to determine a 54 to 60% dose reduction when using the SAFIRE reconstruction software. Noise, CT numbers, homogeneity, low-contrast resolution and high contrast resolution were assessed in a Gammex 438 phantom. Low dose data reconstructed with SAFIRE showed the same image quality compared to full dose data based on this test. Data on file.



Case 3 Unroofed Coronary Sinus Syndrome – Diagnosis with Dual Source CT using Flash ModeBy Hongliang Zhao, MD,* Minwen Zhen, MD,* Yi Huan, MD,* Fu Fu Chen, MD,** Hong Tao Liu, MD**

** Department of Radiology, Xijing Hospital, the Fourth Military Medical University, Xian, P.R. China** Healthcare Sector, Siemens Ltd. China, Shanghai, P. R. China

HISTORY

A 70-year-old female patient with a known history of hypertension presented herself to the hospital complaining of stuffiness in the chest for the past two months. A Dual Source Coronary CT Angiography (CTA) was performed to rule out coronary heart disease.

DIAGNOSIS

The CTA images clearly showed an atrial septal defect (ASD, Figs. 1– 3) with left-to-right shunting. The coronary sinus (CS) opened into the left atrium (Figs. 1– 4), and the great and middle cardiac veins were enlarged before they joined the coronary sinus. An anomalous vascular structure, running in the right atrio- ventricular groove, along with the right coronary artery connected the right atrium and the coronary sinus (Figs. 1–5). Mixed plaques were present in the proximal left anterior descending (LAD) artery with less than 50 % luminal steno-sis (Fig. 6). The other coronary vessels appeared to be normal.



Scan area Heart Pitch 3.4

Scan length 195 mm Slice collimation 128 x 0.6 mm

Scan direction Cranio-caudal Slice width 0.75 mm

Scan time 0.42 s Temporal Resolution 75 ms

Tube voltage 100 kV Reconstruction increment 0.4 mm

Tube current 266 eff. mAs Reconstruction kernel B26f

Dose modulation CARE Dose4D Heart rate 58 bpm

CTDIvol 2.6 mGy Contrast

DLP 67 mGy cm Volume 60 mL

Rotation time 0.28 s Flow rate 4 mL/s

Effective dose 0.94 mSv Start delay 19 s

COMMENTS

Unroofed coronary sinus syndrome (URCS), also called coronary sinus septal defect, is a rare congenital cardiac anom-aly. The roof of the CS is either partially or completely absent resulting in a com-munication between the CS and the left atrium (LA). Trans-thoracic echocardio-graphy is the most widely used imaging modality for suspected unroofed CS, but is limited in its ability to visualize the posterior cardiac structures such as the CS. Dual Source CT, with its excellent spatial and temporal resolution, allows for the visualization and the evaluation of the

posterior structures of the heart. With its widespread use for coronary artery assessment, Dual Source CT is emerging as a potentially useful non-invasive imag-ing modality for the evaluation of the coronary venous system. A variety of new techniques can be combined to reduce the radiation dose and to achieve better image quality. In this case, CARE Dose4D, tube voltage of 100 kV and Flash Mode using a pitch of 3.4 were jointly used to lower the patient radiation dose to only 0.94 mSv.


1–6 The ASD and jet of dense contrast (left-to-right shunt) entering the right atrium (arrowhead), as well as the site of the unroofing (dashed arrows) are shown in Figs. 1–3. An anomalous vascular structure running within the right atrio-ventricular groove along with the right coronary artery connecting the right atrium and the coronary sinus (arrows) are presented in Figs. 1–5. A mixed plaques in the proximal LAD with less than 50% luminal stenosis (double arrows) is visualized in Fig. 6.

5 6

3 4

1 2



Case 4 Diagnosis of Coronary-Vertebral Subclavian Steal Syndrome using iTRIM TechniqueBy PG Pedro, MD,* P Oliveira, RT,* P Coelho, RT,* L Pereira, RT,* D Jesus, RT,* H Pereira, RT,* J Ramalho, RT,* J Costa, RT,* A Chaves, RT**

** Department of Radiology and Cardiology, SAMS Hospital, Lisbon, Portugal** Siemens Healthcare, Portugal

HISTORY

A 59-year-old female patient with multiple cardiovascular risk factors (type II diabe-tes, hypertension, hypercholesterolemia, smoker) had suffered an anterior myo-cardial infarction (AMI) 5 years ago and later developed a CCS class II angina pectoris. Catheterization disclosed an occluded mid-segment in the left anterior descending artery (LAD) and an 80% lesion in the circumflex artery (Cx). A coronary artery bypass graft (CABG) was then performed with a left internal

1 Heart and great vessels isolated volume rendering reconstructions (VRT) show occluded left subclavian artery and retrograde filling of the axillary artery, through the patent LIMA and left vertebral artery. The radial artery bypass graft is occluded and a coronary Cx stent is patent.

mammary anastomosis (LIMA) to LAD and a radial free graft, from LIMA to an obtuse marginal (OM) branch. The patient remained asymptomatic until recently, in spite of the severe risk factors. Three months later, moderate angina reap-peared as well as episodes of dizziness, mainly during upper limb exercise. One month later, a new AMI in the lateral wall occurred. An urgent femoral cathe-terization revealed thrombotic occlusion of the Cx artery. The LAD artery had an

old occlusion and the LIMA graft could not be catheterized. The right coronary artery (RCA) was normal. Primary angio-plasty of the culprit Cx was performed and a bare metal coronary stent was successfully deployed. Rest chest pain was resolved, but mild effort angina and dyspnea resumed one week later. A physical examination disclosed absent pulses in the left arm. A cardiac CT Angiography (CTA) was then performed.

1A 1B 1C


atherosclerotic disease. It is unclear whether the surgical procedure itself accelerates the growth of the lesions in the subclavian artery. This is mainly due to the enhanced local flow and conse-quent endothelial shear stress. In the patient described, pre-operative upper limb arterial pressures were symmetrical and poor risk factors might also have contributed to the subclavian disease progression.In this well-documented case, a large acquisition window, ranging from the middle neck region to the diaphragm, was used to ensure good anatomical coverage; primarily that of the proximal supra-aortic vessels to prepare for a future surgical decision. Since the left carotid artery is disease free, a left carotid-axillary shunt is being proposed.Siemens SOMATOM Perspective with iTRIM technique allowed for fast cardiac CTA acquisition with a higher temporal resolution. Together with the fast volume rendering technique (VRT) on syngo.via, superb anatomic details could be yielded to avoid further invasive studies.

2 Curved multiplanar reformations (cMPR) of the LIMA / LAD (Fig. 2A), RCA (Fig. 2B) and Cx (Fig. 2C).

3 Four chamber (Fig. 3A) and short axis (Fig. 3B) views depict left ventricular wall thinning. Polar map of the left ventricular wall motion (Fig. 3C).

DIAGNOSIS

A total occlusion of the left subclavian artery was demonstrated, 1.8 cm from its origin, proximal to the LIMA and ipsilateral vertebral artery. Both of these supply a scant axillary artery flow (Fig. 1). In spite of this fact, the LIMA was well enhanced, with a good anastomosis to the mid LAD (Figs. 1 A, C and Fig. 2). The radial (LIMA to OM) anastomosis was totally occluded, only a metal clip path could be seen (Fig. 1C). The Cx stent was patent, with no signs of restenosis and the RCA was normal (Figs. 1 and 2). The right brachio-cephalic and left carotid arteries were also normal (Fig. 1). The left ventricular ejection fraction was 53%, with lateral wall and apical akinesis (Fig. 3). The left atrium was enlarged (Figs. 1B and 3A). A complementary triplex Doppler scan disclosed reversal of the left vertebral artery flow. A diagnosis of coronary- vertebral subclavian steal syndrome was confirmed.

COMMENTS

Coronary and/or vertebral subclavian steal syndrome is a well-known late complica-tion of CABG, occurring in patients with pre-existent mild to moderate subclavian

3A

3B

3C

2A 2B 2C


Scanner SOMATOM Perspective

Scan area Middle neck to diaphragm Slice width 0.75 mm

Scan length 250 mm Temporal Resolution 195 ms

Scan direction Cranio-caudal , Feet first Reconstruction increment 0.5 mm

Scan time 12 s Reconstruction kernel B26s and B46s

Tube voltage 130 kV Heart rate 60 bpm

Tube current 289 mAs Contrast Iopromide 370

Dose modulation CARE Dose4D Volume 100 mL contrast + 60 mL salineCTDIvol 32.09 mGy

DLP 974 mGy cm Flow rate 6 mL/s

Effective dose 13.6 mSv Start delay 5 s (Bolus tracking, triggered at 70 HU)


Pitch 0.27



Clinical Results Oncology

Case 5 Minimally Invasive Treatment of Hepatocellular Carcinoma using a Siemens Miyabi System By Taku Yasumoto, MD, PhD,* Katharina Otani, PhD**

** Toyonaka Municipal Hospital, Department of Radiology, Osaka, Japan** Siemens Japan K.K., Healthcare H IM, Research & Collaborations Department, Tokyo, Japan

HISTORY

A 71-year-old male patient, with known hepatitis C, came to the hospital for an annual follow-up. A 4-phase liver CT examination revealed a hepatocellular carcinoma (HCC) with a diameter of 3 cm. The patient was scheduled for transarterial chemoembolization (TACE) to be followed by radiofrequency abla-tion (RFA).

DIAGNOSIS AND TREATMENT

All procedures were performed on a Miyabi system that consists of a CT sliding gantry (SOMATOM Definition AS) and an angiography system (Artis zee ceiling-mounted system). An arterial portography (CTAP, Fig. 3C) was performed to con-firm the HCC diagnosis before treatment began. The contrast media was injected through a catheter that was advanced into the superior mesenteric artery (SMA). The feeding arteries of the tumor came off both the left (LHA, Fig. 1A) and the right hepatic arteries (RHA, Fig. 2A). A super-selective angiogram as well as an embolization was performed at the level of segment 4 in both arteries (Figs. 1B and 2B). The follow-up confirming angio-gram was performed through the com-mon hepatic artery (CHA, Figs. 1C and 2C). The whole procedure was success-fully completed within 120 minutes.A non-contrast CT was performed to con-firm the retention of the Lipiodol® in the

entire tumor (Fig. 4). The RFA procedure was carried out one week later (Fig. 5), successfully completed within 75 minutes. The patient recovered without complica-tions.

COMMENTS

The Miyabi system is an integrated sys-tem with an angiography unit and a CT sliding gantry unit. Both units share a common patient table, facilitating quick transportation of the patient from one unit to the other without risking dislodg-ment of the catheter. Whereas the angi-ography offers higher spatial resolution necessary for detailed imaging of the blood vessels, the CT offers better low contrast resolution which is necessary for imaging the extension of the tumor and to confirm the retention of the Lipiodol in the entire tumor after TACE. The CTAP can obtain much better portal venous enhancement using less contrast media (total volume of 50 mL of 150 mg/mL of iodine at 2.5 mL/s, patient dependent, with a start delay of 25 s, injected through a dual injector as a mixture of contrast medium and saline solution) in compari-son to a standard contrast CT scan (100 mL of 370 mg/mL of iodine at 4 mL/s).The other challenge presented in this case was caused by the special location of the tumor – directly below the diaphragm and above the gallbladder. A critical decision had to be made regarding the access path

of the RFA procedure, necessary to avoid potential complications occurring to the lung or to the gallbladder. The views displayed on the CT monitor and the three dimensional imaging were helpful to ensure a minimally invasive proce-dure.


Scanner SOMATOM Definition AS Sliding Gantry

Scan area Abdomen

Scan mode CTAP

Scan length 206 mm

Scan time 4.5 s


Tube voltage 120 kV


CTDIvol 10.46 mGy

DLP 240 mGy cm


Rotation time 0.5 s


Reconstructed

slice thickness

1 mm

Increment 1 mm

Kernel I30f, SAFIRE

Contrast 150 mg/mL iodine

Volume 50 mL

Flow Rate 2.5 mL/s

Start delay 25 s


1 A CHA angiogram (Fig. 1A) shows the feeding artery from the LHA. Super-selective angiogram and embolization were performed at the level of segment 4 (Fig. 1B), and confirmed by a CHA angiogram (Fig. 1C, arrow).

2 A RHA angiogram (Fig. 2A) showed another feeding artery from the RHA. Super-selective angiogram and embolization were performed at the level of segment 4 (Fig. 2B). The embolization of both feeding arteries at the level of segment 4 (LHA, Fig. 2C, arrow and RHA, Fig. 2C, dashed arrow) was confirmed by a CHA angiogram.

3 CT images of non-contrast (Fig. 3A), arterial phase (Fig. 3B) and CTAP (Fig. 3C) showed the extension of the tumor. The CTAP image showed soft tissue contrast much better.

4 Non-contrast CT image confirmed the retention of the Lipiodol in the entire tumor.

5 CT images discovered the critical access path for the RFA procedure.

1A 1B 1C

2A 2B 2C

3A 3B 3C

4 5


Clinical Results Acute Care

Case 6 Aortic Dissection Follow-Up using Fast Mode with SOMATOM Definition EdgeBy Prof. Hans-Christoph R. Becker, MD

Department of Clinical Radiology, Grosshadern Clinic, Ludwig-Maximilians-University (LMU) Munich, Germany

3

1 2


HISTORY

A 62-year-old male patient suffering from an aortic dissection (Stanford type A) underwent surgical repair. A CT scan was ordered for post-operative control.

DIAGNOSIS

The hematoma around the ascending aorta was successfully removed by surgery, whereas the dissection in the

descending aorta remained. The tear originated in the aortic arch, continued into the origin of the left subclavian artery, down the whole descending aorta, and ended at the iliac bifurcation. The left renal artery originated from the false lumen and resulted in a hypo-perfusion of the left kidney. An arterio-venous fis-tula was suspected in the right femoral artery.

1–5 MPR (Figs. 1, 5) and VRT (Figs. 2, 4) images show that the hematoma around the ascend-ing aorta has been removed (Fig. 1), while the dissection in the descending aorta (Figs. 2–4) remained. The tear originated in the aortic arch, con-tinued into the origin of the left subclavian artery (Figs. 1–3, dashed arrows), down the whole descending aorta, and ended at the iliac bifurca-tion. The left renal artery originated from the false lumen (Figs. 2, 4–5, arrows) and resulted in a hypoperfusion of the left kidney.

4

5

COMMENTS

Fast mode, combining a pitch of 1.7 and a rotation time of 0.28 s, is ideal for long-range CT Angiography (CTA). The image acquisition speed provides, with only a single CT scan, all the relevant informa-tion concerning the patient’s vascular status with a reasonably low radiation exposure and less contrast media. This mode has been routinely performed in our department both for aortic CTA and transcatheter aortic valve implantation (TAVI) planning and control.


Scanner SOMATOM Definition Edge

Scan area Thorax-pelvis

Scan length 593 mm


Scan time 3 s

Tube voltage 100 kV


Dose modulation CARE Dose4D

CTDIvol 2.17 mGy

DLP 137 mGy cm



Pitch 1.7


Slice width 0.75 mm


0.7 mm


I26f, SAFIRE

Contrast

Volume 60 mL

Flow rate 4 mL/s

Start delay 10 s

Acute Care Clinical Results


Clinical Results Orthopedics

Case 7 Metal Artifact Reduction by Energetic Extrapolation in Single Source Dual Energy CT1

By Felix G. Meinel, MD, and PD Thorsten R. C. Johnson, MD

Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Germany

HISTORYA 77-year-old female patient with multiple vertebral metastases from a renal cell carcinoma, which had been stabilized with several spinal fusion operations, presented herself to the emergency room complaining of weak-ness in her left leg. A CT examination

was performed to assess the degree of osteolytic destruction, the integrity and position of the osteosynthetic material and to rule out an infiltration or compres-sion of the spinal canal and the neuro-foramina by metastases or hematoma.

DIAGNOSIS

The CT scan showed a complete collapse of the 9th and 10th thoracic vertebrae (Fig. 1). Advanced osteolytic metastases were also noted in the 11th and 12th thoracic and in the 2nd and 4th lumbar vertebrae (Fig. 1). The osteosynthetic material itself was intact. However, the

1 Sagittal MPR images at extrapolated photon energies of 70, 110, 130, 150 and 180 keV show a marked reduction in metal artifacts with increased extrapolated photon energy.

E = 70 keV E = 110 keV E = 130 keV E = 150 keV E = 180 keV

1A 1B 1C 1D 1E

1 Under FDA review. Not available for sale in the U.S.


2 The effective reduction of metal artifacts at high extrapolated photon energies allows for highly accurate volume rendering technique (VRT) images.

screws had broken through the base plates of the 11th and 12th thoracic vertebral bodies (Fig. 2). There was no evidence of a hematoma or metastatic mass in the spinal canal or in the neuro-foramina.

COMMENTS

Appearing as bright and dark streaks orig-inating from the metallic implants, metal artifacts can greatly hamper accurate CT

interpretation, including the diagnosis of fractures, implant loosening, or to rule out inflammation or hematoma in the surrounding soft tissue. These artifacts can be effectively reduced in Dual Energy CT by generating images extrapolated to higher photon energies. These extra-polated photon energies, with the high-est diagnostic quality, usually fall in the range of 100-130 keV. This technique can be applied for the examination of metallic implants of various types and

alloys and their surrounding tissues.Pathologies of the spine can be extremely challenging to assess in patients after spinal fusion surgery, due to substantial metal artifacts in both CT and MRI scans. Energetic extrapolation effectively reduces metal artifacts in Dual Energy CT and allows for an accurate assessment of the spine, the spinal canal and the neuro-foramina in such patients.


Scanner SOMATOM Definition Edge

Scan Mode Single Source Dual Energy DLP 482 mGy cm / 629 mGy cm

Scan area Spine Effective dose 7.2 mSv / 9.4 mSv

Scan length 415 mm Rotation time 0.5 s

Scan direction Cranio-caudal Pitch 0.5 / 1.2

Scan time 11 s Slice collimation 128 x 0.6 mm

Tube voltage 80 kV / 140 kV Slice width 1 mm

Tube current 600 mAs / 142 mAs Reconstruction increment 1 mm

Dose modulation CARE Dose4D Reconstruction kernel Q40f

CTDIvol 11 mGy / 14 mGy

2A 2B 2C


Clinical Results Orthopedics

Case 8 Metal Artifact Reduction using Dual Energy CT Monoenergetic Imaging By Qiaowei Zhang, MD,* Prof. Shizheng Zhang, MD,* Chenwei Li, MD**

** Department of Radiology, Sir Run Run Shaw Institute of Clinical Medicine of Zhejiang University, P. R. China Sir Run Run Shaw Hospital School of Medicine of Zhejiang University, P. R. China

** Healthcare Sector, Siemens Ltd. China, Shanghai, P. R. China

HISTORY

A 65-year-old male patient, who had undergone an ORIF (Open Reduction Internal Fixation) procedure for a lateral femoral neck fracture the previous year, was referred to the CT department for a follow-up assessment. A Dual Energy CT scan was performed using monoenergetic imaging to reduce the metal artifacts.

DIAGNOSIS

The metal artifacts were pronounced at 70 keV (proximately equivalent to 120 kV setting, Fig. 1A), but were substantially reduced by increasing the energy level, e.g. to 110 keV (Fig. 1B) and 150 keV (Fig. 1C). A transversal break through the proximal section of the implant was also found (Figs. 2 and 3).

1A

1 Axial images present significant metal artifact reduction from 70 keV (Fig. 1A), to 110 keV (Fig. 1B) and 150 keV (Fig. 1C) settings.

COMMENTS

In ORIF follow-up examinations, it is important to assess the metal implant, the interface between the implant and the bone structures, as well as the surround-ing tissues. Metal artifacts, however, represent a significant limitation in CT assessment. Structures are sometimes not interpretable even when using hard

1B 1C




Scan area Hip DLP 303.6 mGy cm

Scan length 253 mm Effective dose 4.6 mSv

Scan direction Cranio-caudal Rotation time 0.5 s

Scan time 18 s Pitch 0.6

Tube voltage 100 kV / Sn 140 kV Slice collimation 40 x 0.6 mm

Tube current 95–231 eff. mAs / 85–163 eff. mAs

Slice width 1 mm

Dose modulation CARE Dose4D Reconstruction increment 1 mm

CTDIvol 12 mGy Reconstruction kernel D40f

convolution kernels and widened CT window settings. Dual Energy CT with monoenergetic imaging method allows dose-neutral acquisition at 100 kV and 140 kV simultaneously. It provides a wider range of energy settings (50 to 190 keV) which the users can freely apply to achieve the optimal level for substantial metal artifact reduction. Thus, the image quality can be greatly improved for diag-nosis.

2 VRT image shows the location of the implant in the left femur.

2 3A

3 VRT images demonstrate the transversal break in the proximal section of the implant.

3B

Orthopedics Clinical Results


Science

Research Clusters Enable Transfer of Basic Research to Clinical RoutinePart II. Concentrated Expertise Against Coronary Heart Disease

By Monika Demuth, PhD


For men over 50, the risk of suffering from a heart attack in the next 10 years due to coronary heart disease (CHD) is 5–10%.[1]Behind these numbers lie human trage-dies, but also immense costs for the healthcare system. These were sufficient reasons for the University of Erlangen-Nuremberg (Cardiology and Radiology) and Siemens Healthcare to jointly par-ticipate in the Leading Edge Cluster competition organized by the German Federal Government within the ‘Medical Valley – European Metropolitan Region Nuremberg’ cluster.

The Leading Edge Cluster competitionBetween 2007 and 2010, the German Federal Government initiated three com-petitions. The aim was for science and business to co-operate and co-ordinate closely to apply for funding with concepts which, based on the strengths of the cluster, pointed to untapped develop-ment potential. The fundamental idea behind the thematically unrestricted Leading Edge Cluster competition was to strengthen Germany, for the long term, as a location for innovation and business.Among those Leading Edge Clusters that were selected in the second round is, for instance, ‘m4 – personalized medicine and goal-oriented therapies – a new dimen-sion in medical development’ (see part 1 of the report in SOMATOM Sessions 30).Another medical technology cluster selected from the second round is the cluster ‘Medical Valley – European Metropolitan Region Nuremberg’. The

between patient characteristics and image quality must be collected. On the technical side, detector design and recon-struction algorithms mainly must be further developed in a targeted manner. Finally, new technology must be validated. Within the joint project, technology development is undertaken by Siemens Healthcare, while clinical aspects are covered by a cooperation between the Department of Cardiology and the Insti-tute of Radiology at University Hospital Erlangen-Nuremberg.Cardiology and radiology research groups at the University Hospital, led by Prof. Stephan Achenbach, MD, Prof. Dieter Ropers, MD and Prof. Michael Lell, MD, have been working together especially closely for many years. It is based on this long-standing cooperation that sub-stantial progress in cardiac and coronary imaging using CT has been made.In cardiac imaging there has been a move away from the retrospectively ECG-gated spiral scan, towards prospectively ECG-triggered step-and-shoot scan, on the one hand, and high-pitch scan on the other. Using this latter method, it was possible to conduct the heart scans of all the patients examined at under 1 mSv.Previously, image noise had been a prob-lem with the extremely low radiation doses used but the Leading Edge Cluster project solved this by developing patient adapted scan protocols using new tech-nologies such as iterative reconstruction, automatic tube voltage setting and new detector designs. This combination results in very good image quality at minimal X-ray doses. Many of the new techniques

members of this Leading Edge Cluster have taken on the task of improving the quality of healthcare, while simultane-ously lowering the costs.

Improve coronary CTOne project within the cluster is dedicated to developing new technologies and pro-cedures for non-invasive examination of the coronary arteries. New procedures for computed tomography are to be devel-oped and validated, procedures that will improve the obtained images of the cor-onary arteries and enable the detection and quantification of atherosclerotic plaques with improved spatial and tem-poral resolution, while also reducing exposure to radiation. The ultimate goal of the project is to improve prevention of CHD, which would potentially include preventive care approaches.When the joint project was designed and initiated, Dual Source CT had been intro-duced and, for carefully selected patients, high quality imaging of the coronary ves-sels was possible with a radiation dose below 1 mSv. One of the project aims is to develop and validate techniques which will allow low-dose imaging in all patients, in order to be able to more broadly apply coronary CT Angiography – potentially including asymptomatic individuals with an increased risk.

Close cooperation to optimize dose and image qualitySeveral equally important components are required to optimize image quality while reducing dose: Clinically, funda-mental information on the relationship


Science

1 One of the project aims is to develop and validate techniques which will allow high-quality imaging of the coronary vessels with a radiation dose below 1 mSv. In this case an extremely low radiation dose of 0.078 mSv was sufficient. Courtesy of University Hospital Erlangen-Nuremberg, Germany

2 A major success on the way to significantly reducing image noise by using very low radiation doses was the broad introduction of SAFIRE (Sinogram Affirmed Iterative Reconstruction): without SAFIRE (Fig. 2A), with SAFIRE (Fig. 2B). Courtesy of University Hospital Erlangen-Nuremberg, Germany

are already available as products. A major success was the broad introduc-tion of iterative reconstruction procedures (SAFIRE) and automatic tube voltage setting (CARE kV).

Scan protocols individualizedHere, the advantage of individually opti-mized scan protocols for each patient was evident: the kV value can be adjusted to the optimum level for each case. Patients with a high BMI are particularly problematic. In such cases, by means of the software component CARE kV, the CT scanner software offers aid in decision making. Based on the patient’s topogram, the first very low-dose overview scan included in every CT scan for planning purposes suggests the optimum kV value. Thus, individualized examination proto-

cols are created. Similar problems must be dealt with in patients with a broad thorax-wall cross-section. To deal with such a fundamental, complex problem and in order to identify the crucial para-meters, comprehensive basic data was gathered in the first 3 years of the project. These data led the clinicians to a better understanding of the factors that influ-ence the image quality and the correlated sensitivity and specificity of the methods. Additionally, they achieved a signifi-cantly improved dose to image quality relationship which permitted reliable clinical diagnoses.

Further project stepsWith respect to this, more advanced tech-nologies such as iterative reconstruction based on raw data proved to be helpful,

as did new detector technology. The pre-requisite conditions for pursuing further sub-goals have thus now been estab-lished. In the next phase of the project, post-processing software will be further developed and validated. This would make the automatic analysis of atherosclerotic plaques possible to avoid individual vari-ations on the part of the evaluator, and could achieve even better reproducibility. The clinical data must, of course, also be further validated. Here, improved image quality achieved by means of iterative reconstruction and plaques characteriza-tion based on low-dose data sets should be the focus.New detectors that are currently being developed will be able to count individual X-ray photons and determine their indi-vidual energy and increase spatial reso-

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“Leading Edge Cluster funding like this allows excellent collaboration between scientific institutes and industry and reinforces the advance-ment of innovation and business in a country in the long run.”

Prof. Michael Lell, MD, Dept. of Radiology, University Hospital Erlangen-Nuremberg, Germany

“As part of the Leading Edge Cluster project we developed scan-conditions to obtain high-quality images with less than 1 mSv in all heart patients examined.”

Prof. Dieter Ropers, MD, Dept. of Cardiology, University Hospital Erlangen-Nuremberg, Germany

“We expect the data compiled during the project prospectively affecting

the course of CT imaging for the diagnosis and prevention of CHD.”

Prof. Stefan Achenbach, MD, Dept. of Cardiology, University Hospital Erlangen-Nuremberg, Germany


3 N = 165, Schuhbäck A, et al (Invest Radiol in press) The kV value can be adjusted to the optimum for each case – even for patients with a broad thorax-wall cross-section (Figs. 3A, 3C) or with a high BMI (Fig. 3B).

lution even further. These new detectors have the potential to drive patient dose down even further and increase image quality which could result in an even higher specificity for the evaluation of early signs of coronary artery disease.Results gained by the three experts Stefan Achenbach, Dieter Ropers and Michael Lell during the cooperation described (within the framework of the Cutting-Edge project at the University of Erlangen-Nuremberg) included new data acquisition protocols, new detector technologies, new image reconstruction techniques and the opportunity to use patient-specific optimized scan-para-meters. These results should allow an optimization of image quality and, more-over, considerably reduced radiation exposure. The results, which will be col-lated at the end of the project, will influ-ence the direction that CT imaging for the diagnosis and prevention of CHD will take in the future.Based on the achievements in the first phase of the project, the jury of renowned experts decided during the extensive project review phase also to fund the second phase of the project until 2015.

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[1] Conroiy et al, Estimation of ten-year risk of fatal cardiovascular disease in Europe: the SCORE project. Eur Herat J 2003.

In clinical practice, the use of SAFIRE may reduce CT patient dose depending on the clinical task, patient size, anatomical location, and clinical practice. A consulta-tion with a radiologist and a physicist should be made to determine the appropriate dose to obtain diagnostic image quality for the particular clinical task. The product/feature (mentioned herein) is currently under development; is not for sale in the U.S. Its future availability cannot be guaranteed.


Science

Image Quality in Computed TomographyPart I. Low Contrast Detectability

By Stefan Ulzheimer, PhD


Image quality in computed tomography (CT) can be described using several para-meters such as image noise, high con-trast spatial resolution and low artifact content. Low contrast detectability, some-times also called low contrast resolution, is often considered a key parameter as well.For low contrast detectability (LCD), how-ever, there is decisive difference compared to other image quality parameters: as opposed to, for example, high contrast spatial resolution, it is not a well-defined image metric and cannot easily be mea-sured objectively. This article explains the concept of low contrast detectability, how

1A The CATPHAN® phantom (The Phantom Laboratory, New York) or a similar phantom with a respective low contrast test insert can be used to determine the low contrast detectability. (Images courtesy of The Phantom Laboratory, New York, USA)

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1B The low contrast insert of the CATPHAN® phantom with a 200 mm diameters; and periodic inserts with diameter and contrasts in the range of 2 to 15 mm and 3 to 10 HU, respectively, as an example of a low contrast detectability test phantom.

it can be measured and what the pitfalls in the assessment are.

Low contrast detectability and image noiseIn general, every measurement is associ-ated with a certain margin of error and all measured values fluctuate around the true value. In CT the value that is mea-sured is the attenuation caused by the object, represented by its Hounsfield (HU) value. Each volume element (voxel) of a CT image is a measurement of the respective attenuation caused by the scanned object. Therefore, if a CT scan of the same object is repeated, the scan

will always yield a slightly different CT value for this voxel. If a homogeneous object such as a water phantom is scanned, each voxel in the image can be interpreted as an independent measure-ment of the same material. Thus, a CT scan of a homogeneous object can be interpreted as many independent mea-surements of the same material carried out at the same time. All voxel values will fluctuate around the true value of, for example, water. The measurement error is directly visible in the image and is usually called image noise. If a sufficiently large amount of measurements are carried out, the aver-

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age of the measured values is close to the true value. In a CT image the image noise and the true HU value can be estimated by evaluating a sufficiently large homo-geneous region of interest (ROI) in the image and calculating the standard devi-ation and the average in that ROI. Small attenuation differences can only be detected when the image noise is suffi-ciently small.In general, LCD aims to describe the per-formance of a CT system in detecting objects of low contrast against the back-ground. Ideally, one would define an objective test method, for example, using phantoms, to assess LCD for scanner characterization.In current practice, LCD is typically spe-cified by measuring a low contrast phan-tom with objects of different sizes and different densities. Fig. 1 shows a typical test phantom with a respective low con-trast (LC) insert. One then specifies which insert can presumably be seen at a cer-tain dose level with a certain scan proto-col. A sample specification may look like this: 5 mm, 3 HU @ 11.0 mGy CTDIvol

(200 mm CATPHAN® phantom, 10 mm slice width, 120 kV, typical body mode).This means that when the 200 mm CATPHAN® phantom with the LC insert at a dose of 11.0 mGy is scanned (in terms of CTDIvol in the 32 cm phantom) with a standard body protocol, the per-son assessing should be able to see the 5 mm, 3 HU insert.The crux lies in the presumed ability to see a certain low contrast structure, since for an individual this is a highly subjec-tive task. It makes it difficult to obtain statistically objective data with some level of confidence using visual methods.

Radiologists do not evaluate images statisticallyStatistical performance parameters are often considered to be an indication of the system’s LCD performance [1, 2] and respective criteria have been formulated. However, the LCD not only depends on the noise in relation to the contrast differ-ence, but also on the size and shape of the lesion and the surrounding tissue. In daily practice it all boils down to what a human reader can see in the image – the diag-

nosis will be based on what the reader can recognize. If image noise is too high, low contrast objects or lesions are hidden behind that curtain of noise. Experienced readers can see through noise better than inexperienced readers. Therefore, the experience of the reader affects the LCD in addition to the level of image noise.[3] Reader experience, however, is only one of the many parameters that influence LCD (Table 1).To be able to carry out a valid comparison of the LCD performance of a CT scanner all parameters that influence LCD, besides the scanner itself, have to be kept con-stant. It is clear that this is a rather chal-lenging task, if possible at all.

Various approaches to LCD specificationOne reason for the lack of a well-defined objective method to assess LCD is that various manufacturers use different meth-ods to specify LCD performance of their

systems. These approaches can be sum-marized in three different categories:

■ The conservative approach■ The optimistic approach■ Monkey Business

So, LCD involves the specification of a certain object “being seen” by an observer. As discussed above, the measurement itself is a statistical process and, especially when pushing the limits of detectability, it automatically follows that not every reader will see the lesion in every image. There will even be images acquired with the very same scanner and same scanning parameters where the same reader will see the insert in one scan but not in the other.Different manufacturers have different ideas of what it means to “see the lesion”. Siemens uses a very conservative approach. Ten experienced readers read ten independently acquired data sets

Table 1: Parameters that influence LCD

Observer Experience; How well can he or she eliminate bias; What are his or her goals

Scan Parameters Dose and dose distribution; Collimation

Reconstruction Parameters Slice Thickness; Reconstruction kernel; In-Plane Resolution

Reading Conditions Ambient Light; Monitor; Ability to window

EvaluationHow many readers; How many have to detect the insert; Do they have to detect only the smallest or all bigger inserts

PhantomManufacturing quality; Reproducibility; Patterns of inserts

ScannerDetector; Dose efficiency; Artifact suppression; Scatter radiation

Low Contrast Object Density; Size; Shape; Background material


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measured with the same parameters. For the specified dose level, at least 50% of the readers must detect the low contrast object in at least 50% of the data sets. Additionally, Siemens exclusively uses standard clinical protocols exactly as speci-fied in the System Owner Manual to deter-mine the LCD.Optimistic approaches which may be applied by other manufacturers typically use much softer criteria to determine the LCD for their systems. If fewer readers are included who are more optimistic and also use softer criteria for the evaluation, the result would consequently lead to much better specifications.Of course, one has to keep in mind that by measuring the LCD in well-defined phantoms, the same lesion patterns are always in the same location so that read-ers already know where to look and what for. Even for a reader with the best inten-tions, it is very hard to eliminate bias.The manner in which the measurements

2A The LC insert of the CATPHAN® phantom scanned with a standard body protocol on a SOMATOM® Definition AS+ with a CTDIvol of 11.0 mGy reconstructed with a 10 mm slice width. 50% of readers could detect the 5 mm, 3 HU insert (orange arrow) in more than 50% of the data sets. Therefore, Siemens specifies LCD for the SOMATOM Definition AS+ as 5 mm, 3 HU @ 11.0 mGy.

2B The LC insert of the CATPHAN® phantom scanned with a standard body protocol on a SOMATOM Definition AS+ now with a CTDIvol of 17.0 mGy again reconstructed with a 10 mm slice width. It is obvious that the noise level is reduced and this time 50% of the readers could detect the 3 mm, 3 HU insert (arrow head) in more than 50% of the data sets.

are evaluated can even dramatically influ-ence the results. Even stricter rules than Siemens currently uses can be applied, for example, that all consecutive inserts from 15 mm down to the desired one have to be detected by all readers in all cases. That requirement alone would lead to dramatically lower LCD specs for all scanners without changing anything else.On the other hand, simply relaxing some of the rules can result in much better LCD values. Based on Fig. 3, Siemens could also specify a LCD of 2 mm, 3 HU @ 11.0 mGy just by relaxing the rules so that only at least one observer has to detect the insert without changing anything else.While the “optimistic approach” could still be justified by at least specifying the evaluation method in datasheets, taking the “optimization” of LCD one step further leads to Monkey Business. Acquisition protocols and reconstruction parameters can always be tweaked in such a way that

LCD values are dramatically improved but with an outcome that is completely irrel-evant clinically.One example is to use scan protocols that are never used in clinical routine and are designed only to give good LCD at very low doses. This can be done by introduc-ing special X-ray filters or collimators that are adapted only to measure good LCD in the established CTDIvol and LCD test phan-toms. Another way is to design special reconstruction kernels optimized for this particular task that are never used in a clinical setting.In the end, it is important to keep in mind that all tricks to optimize LCD work only in defined phantoms, but these numbers will be meaningless when looking at real patients.

The devil is in the detailIn data sheets often only a couple of values specifying LCD can be found with-out telling exactly how these values were

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References[1] ICRU Report 54: 1995, Medical Imaging – The

Assessment of Image Quality (7910 Woodmont Ave., Bethesda, Maryland USA 20814)

[2] ASTM E 1695 – 95: 1995, American Society for Testing and Materials ASTM

[3] Thilander-Klang A, et al. Evaluation of subjective assessment of the low-contrast visibility in con-stancy control of computed tomography. Radiat Prot Dosimetry. 2010 Apr-May;139(1-3):449-54.

obtained. The goal of this article is to explain what LCD is, how it can be mea-sured, as well as its limitations and poten-tial pitfalls. It needs to be considered that there is no generally accepted and well-defined method of determining LCD given the difficulty of obtaining statisti-cally objective data with some level of confidence. There are many parameters that influence LCD and not all of them are related to the CT system. If parameters are not kept constant, it is false to com-pare the performance of CT systems based on these values. The bottom line is that as long as a manufacturer does not explain how exactly he determines the LCD and as long as CT users do not ask the right questions these specs will be completely meaningless. Efforts are currently being made at national and international levels to standardize some of the methods used in practice. One approach is to standard-ize evaluation by using mathematical model observer studies [4] to eliminate this uncertainty from the equation at least.

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3 Minimum low contrast insert size in the 200 mm CATPHAN® phantom detected by 10 differ-ent experienced readers for 3 HU density with data from the SOMATOM Definition AS (typical body protocol, 120 kV, 11.0 mGy). There is a huge variation even between experienced readers depending on how well they eliminate bias because all readers know where the inserts are. Two readers could detect the 2 mm insert and one reader could only see the 8 mm insert.

In most Siemens data sheets only LCD values for the 5 mm, 3 HU insert of the 200 mm CATPHAN® phantom are specified. Of course, that does not mean that smaller inserts cannot be detected. This table shows at roughly what dose levels smaller inserts can be reliably detected based on Siemens’ conservative rules for five different systems.1

Table 2: LCD for different insert sizes

SOMATOM Definition Flash

SOMATOM Definition AS

SOMATOM Perspective

SOMATOM Emotion

SOMATOM Spirit

5 mm, 3 HU 11.0 mGy 10.7 mGy 11.2 mGy 11.8 mGy 11.9 mGy




[4] Hernandez-Giron I, et al. Automated assessment of low contrast sensitivity for CT systems using a model observer. Med Phys. 2011 May;38 Suppl 1:S25.

1 Data on file.


Science

CARE kV Allows a Reduction of Radiation DoseAt Erasmus Medical Center in Rotterdam, the Netherlands, the work of CT technologists has been made easier thanks to CARE kV. This unique software tool reduces radiation by optimizing tube voltage.

By Irène Dietschi

The baby was just five weeks old when it was admitted to the Erasmus Medical Center (MC) radiology department in Rotterdam for a thorax scan. The radiol-ogist required a visualization of the child’s aorta and vascular system; however, because it was a neonate patient, the technologists put special emphasis on reducing radiation to very low levels (Fig. 1).It was thanks to CARE kV – the unique Siemens tool that determines the ideal tube voltage according to the individual patient and clinical situation – that tech-nologists were able to perform the proce-dure on such a young patient. With CARE kV they chose a tube voltage of just 70 kV:

you can choose a low kV, and the soft-ware will provide the lowest possible ref. mAs.”The infant’s examination was carried out at the beginning of May 2012, at the same time that CARE kV was introduced in the Erasmus MC radiology department. With more than 11,000 employees and 1,300 beds, the hospital is the largest of eight university hospitals in the Netherlands. Since that exam, Booij and Dijkshoorn have gained considerable experience with the new software tool. Moreover, they have passed this knowl-edge on to their colleagues. They explain that once you have learned a few basic rules, it is easily implemented. As of the end of August, they had been running CARE kV on two of the department’s six Siemens scanners. Booij and Dijkshoorn are delighted with the software and intend to roll it out on two further scanners in the near future: “Thanks to CARE kV, we are able to reduce doses and still achieve better images,” Booij says. “It has made our lives a lot easier.” Because their patients receive smaller doses while image quality was not impaired, the technolo-gists have less to worry about.

A balancing actBooij and Dijkshoorn have been modu-lating tube voltages in their practice for years because they know that this helps to reduce radiation doses. However, they had to do it manually before – no easy task within a daily routine. The relation-ship between tube current, tube voltage and image quality (contrast, noise and CNR, the contrast-to-noise ratio) in CT makes it an intricate procedure; therefore,

“The resulting dose was so low, it was almost unbelievable,” says technologist Ronald Booij, coordinator of the depart-ment’s Research & Innovation CT unit.

Tiny dose for a tiny patient“We calculated a DLP – Dose Length Prod-uct – of just 2.8 mGy cm, which is very low,” his colleague, Specialized Research CT technologist Marcel Dijkshoorn adds. Nevertheless, they produced an impec-cable vascular exam with the aorta, the lungs and the heart clearly defined.“In a small patient, lowering the tube voltage has almost no effect on image noise, and the iodine gives you a good contrast,” Booij explains. “This means

At Erasmus Medical Center in Rotterdam the patients receive smaller doses thanks to CARE kV. So technologists Marcel Dijkshoorn (left) and Ronald Booij (right) are happy to have less to worry about.


adjusting the tube voltage for each indi-vidual patient and exam is a challenge: “Every kV adaptation requires an appro-priate mAs adaptation as well,” Dijkshoorn explains, “and the adaptations must differ for native arterial or venous scans, paren-chyma, vessel or bone studies and, of course, according to the patient’s body habitus.” This is a very time-consuming process, which requires significant exper-tise from all the CT technologists.At Erasmus MC, which conducts more than 200,000 diagnostic radiological exams annually, technicians would con-centrate on protocols where either image quality improvement or dose savings were greatest: “Performing this manually conflicts with workflow optimization,” says Dijkshoorn. “Either the number of protocols or their complexity increases, with specific low and high kV settings relative to the patient’s weight or BMI.”CARE kV eliminates the need for these protocols. In general, a standard scan protocol for a clinical situation is now sufficient, regardless of the size of the patient – whether pediatric or adult: “Implementing CARE kV, along with our use of SAFIRE and the new Stellar Detec-tor, were the reasons behind our decision to completely rework our protocols and configure them in the best possible way,” says Booij. And whereas kV modulation was formerly an option that depended on the experience of CT technicians, CARE kV has made it much easier to handle. “The tube voltage is now optimized automati-cally for almost any patient or clinical sit-uation,” says Ronald Booij. Patients bene-fit from lower doses, and the technicians from less stress. “Because things are easier, you are more relaxed conducting your examination.”

Benefits in PediatricsIn pediatric CT especially, this is highly beneficial, where it is a delicate balancing act between good quality images and acceptable doses: “Pediatric CT is very demanding for both the doctor and the technician,” Dijkshoorn states. At the same time it is clear that the developing bodies of children should be exposed to as little radiation as possible. CARE kV simplifies the scanning process significantly:

■ Excellent images and dose reductions of up to 60%.

■ At Erasmus Medical Center, more patients are now referred for CT instead of MRI and angiography, which means the same information can be rendered in an exam taking only a few seconds.

“Since more pediatric patients are now referred to CT, and because the proce-dures have become more simple, the CT technicians can clearly gain as a group in their routines,” Dijkshoorn says. “There is now sufficient expertise not only to make good scans during office hours, but also in the evening and during night shifts.”Dijkshoorn and Booij are keen to point out that despite these advantages, every CT scan must have a clinical indication justifying the radiation and contrast media – regardless of how low it is: “But with doses decreasing, we notice a shift from MRI to CT because the possible com-plications in MRI exam may outweigh convenience.”

When every second countsWhat applies to pediatric CT is similarly true within the emergency setting, where CARE kV also brings benefits: “In situa-tions where every second counts, you don’t have time to think of dozens of protocols,” Booij explains. “You need to work as fast as you can – often by your-self, without the advice of a colleague – so it is a great relief to have a robust protocol and reliable software to obtain optimal results.”Booij recalls the case of an 18-year-old female cystic fibrosis patient, who was referred to radiology with haemoptysis and a light fever. Considering emboliza-tion, the doctors urgently needed to know the cause of the bleeding and asked for a detailed visualization of all the vessels in the lung: “This scan is usually done with 100 kV, which results in a DLP of ± 80 mGy cm; however, in this case, the DLP was just 28 mGy cm, while CARE kV had chosen 80 kV.” The scan revealed a sequester in the right lower lobe, and no treatment was necessary.CARE kV also offers a ‘semi’ mode. This allows a user-specified kV setting to be

used, with the software adjusting mAs values according to the specified refer-ence values. “This is particularly helpful for multi-phase follow-up exams, such as the wash out measurement of an adre-nal gland,” Dijkshoorn notes. A constant kV setting allows comparison between multiple scans and/or exams conducted on the same patient.At Erasmus MC, the education element of CARE kV started long before the soft-ware was installed. Although it is quite simple to use, understanding the back-ground is more sophisticated: “We wanted the whole group to know that something big was coming that would change their work tremendously,” Booij recalls. “We found it extremely important for every-body to be aware of the scope of the new tool.” In his and Dijkhoorn’s view, the training of technicians and radiologists should be done simultaneously, allowing them to create new protocols together: “You get the most benefit from training when doctors and technicians join forces.”

Irène Dietschi is an award-winning Swiss science and medical writer. She writes for the public media, such as the Neue Zürcher Zeitung and has published several books.

1 A five-week-old baby was admitted to the Erasmus Medical Center (MC) radiology department in Rotterdam for a thorax scan. A visualization of the child’s aorta and vas-cular system was required. CARE kV allowed the radiologist to conduct the scan using the lowest possible radiation dose (CTDIvol 0.1 mGy, DLP 2 mGy cm, eff. dose 0.078 mSv).

1

The statements by Siemens’ customers described herein are based on results that were achieved in the customer’s unique setting. Since there is no “typical“ hospital and many variables exist (e.g., hospital size, case mix, level of IT adoption) there can be no guaran-tee that other customers will achieve the same results.

Clinical Fellowships: Localized Learning from the ExpertsBy Susanne von Vietinghoff, Computed Tomography, Siemens Healthcare, Forchheim, Germany

During a clinical fellowship, Siemens Healthcare provides customers with the opportunity to learn from clinical experts at their institute about their typical proven workflows. A clinical expert guides participants through their daily workflow and shows how examinations are con-ducted (including choice of protocols or contrast injection timing). Furthermore, users can learn how to do post-process-ing and how to write reports. In addition, numerous tips and tricks straight out of clinical routine are given directly at the fellowship location. This hands-on train-ing moves at the pace of the hospital, creating an authentic practical experi-ence.Currently, there are sixteen different fellowship locations available globally

with scanners ranging from SOMATOM® Emotion 6 to SOMATOM Definition Flash. Fellowship training takes place at private institutes as well as at university hospitals. Siemens offers dedicated sites for scan-ning in the Emergency Room and in the Neuroradiology and Cardiology Depart-ments. So there are fellowship locations available for every field of interest.Please don’t miss this excellent training opportunity – contact your local sales representative.An up-to-date list of fellowship locations can be found here:

www.siemens.com/ SOMATOMEducate

Ralf Bauer, MD, (left) and Matthias Kerl, MD, (right) are in charge of the CT fellowship program at the Johann Wolfgang Goethe University in Frankfurt, Germany.

The next chance to attend one of these workshops is at ECR 2013 in Vienna, Austria.

ESC Hands-on Tutorials (HoT’s) By Susanne von Vietinghoff, Computed Tomography, Siemens Healthcare, Forchheim, Germany

www.siemens.com/ SOMATOMEducate

In 2012 Siemens once again provided HoT’s for Cardiovascular CT and MR, Car-diac Molecular Imaging, Interventional Cardiology, Echocardiography and Cardiac Lab testing. The aim of the six CT ses-sions held by Matthias Kerl, MD, from the University of Frankfurt, Germany, was to discuss with the attendees – most of them cardiologists – the opportunities that CT offers for cardiac scanning. Matthias Kerl presented everything from scanning techniques to contrast media injection protocols. After the short introduction it was time to experience syngo.via live while evaluating cardiac datasets. Keerthi Prakash, MD, from the

University of Leeds, UK commented after attending the HoT: “I received a good introduction to the basic principles of scanning and post-processing. It was a really good hands-on experience and an enjoyable session, allowing great interaction with the speaker.” Nik Abidin, MD, from Salford Royal Hospital NHS FT in Manchester, UK, commented: “Very good introductory lectures aiming to present the strength of the modality. Good case presentations, demonstrating the utility of CT in cardiac scanning. The cases demonstrated helped our under-standing of how the investigative tools support clinical decision making.”


Customer Excellence

The new software for the SOMATOM Definition may give clinical professionals more time to concentrate on patient care.

Flash Imaging brings together clinical expertise and experience from all over the world regarding CT scanning with the SOMATOM Definition Flash.

New Dual Energy Technology for SOMATOM Definition By Katharina Linseisen, Computed Tomography, Siemens Healthcare, Forchheim, Germany

Flash Imaging – A Book Full of Flash ExpertiseBy Heidrun Endt, MD, Computed Tomography, Siemens Healthcare, Forchheim, Germany

As the first Dual Source scanner, the SOMATOM® Definition revolutionized the world of CT.Now, it will take another evolutionary step. The new software syngo CT 2012B provides FAST Dual Energy1 and the innovative FAST CARE Platform. All cus-tomers with a syngo Evolve contract, Siemens’ non-obsolescence program, benefit from a software-only upgrade delivering innovative technology.

FAST Dual Energy1

To date, SOMATOM Definition customers worldwide enjoy using Dual Energy (DE) in daily practice. FAST DE now is designed to speed up workflow by enabling easy and intuitive direct 3D-reconstructions

of acquired DE data. Time consuming, error prone, manual reconstruction steps have been eliminated. In addition, the data volume is reduced, saving filming and archiving resources.

FAST CARE platformFAST CARE technology may give medical professionals more time for their patients. FAST features like FAST Adjust accelerate the workflow via intuitive scan para-meter adjustment at the push of a button. These features are combined with CARE functionalities such as CARE kV, the first automated kV-setting, that reduces dose by up to 60%.2

Thus, the new software levers untapped potential in patient-centric productivity.

1 Delivered to all customers with Dual Energy and a syngo Evolve contract.

2 Data on file.

www.siemens.com/CT-Infoportal

Then navigate to Recommended CT Literature; Protocols

The book Flash Imaging, published by Springer in May 2012, reports on clinical expertise gained using the SOMATOM® Definition Flash. The authors from all over the world share their best practices as regards scan and contrast protocols and provide additional helpful hints as well as clinical cases.In this comprehensive compendium an introductory section describes the tech-nology of the scanner and new insights into the use of contrast medium in com-puted tomography scanning. Editors renowned for their outstanding research contributed to one of the following clinical chapters: Sub-mSv Cardiac, Dual Energy CT, Flash Thorax and Special Flash

Topics. In each chapter authors from different countries in Asia, Europe and America give detailed information about how SOMATOM Definition Flash is used in their departments. With its unique technologies, such as Dual Source Dual Energy or the Flash Spiral high-pitch mode, the SOMATOM Definition Flash opens up new possibilities for CT scan-ning. This book provides an excellent overview of these new uses. It allows the reader to look behind the scenes of well-known clinical departments and offers a guide to an optimized use of the scanner in daily routine. Free copies can be ordered via the Customer Information Portal on the Siemens Internet.

Flash ImagingAchenbach

JohnsonLee

LengsfeldUlzheimer

(Eds.)

Flash Imaging

This compendium provides a comprehensive source of scan and contrast protocols as well as additional information for all important indications for the second-generation DSCT scanner, the Siemens SOMATOM Defi nition Flash.

The focus of all contributing centers has been on the optimization of both scan and contrast parameters, since contrast media delivery has become an increasingly critical element of contrast-enhanced procedures

in modern CT imaging. The protocols also aim to achieve excellent images with the lowest possible radiation exposure by exploiting the unique features of the SOMATOM Defi nition Flash.

Refl ecting expertise and experience from across the globe, contributions to this volume have been elicited from renowned radiology centers in Europe, America, and Asia.

Achenbach • Johnson • Lee • Lengsfeld • Ulzheim

er (Eds.)Flash Im

aging

springer.de


Customer Excellence

Customer Excellence

How can you speed up the workflow in intervention and still save on dose? Since the syngo CT 2011A software ver-sion was introduced for the SOMATOM® Definition Flash, SOMATOM Definition and SOMATOM Definition AS, it has become possible to significantly speed up the workflow and use a lower dose in 3D Interventions.*Maximum image quality can be achieved using minimum dose for each patient by a combination of the Adaptive Dose Shield, which eliminates over-radiation in every spiral scan, and the real-time dose modulation offered by CARE Dose4D™. In clinical routine, an ad hoc situation sometimes requires a CT intervention. Prior to the intervention a normal spiral

alignment with the images in the tomo-segment.Another option to speed up the work-flow during intervention is to load a series from the “Patient Browser” or a prior scanned series and use them as a reference. To do this, open the “Patient Browser”, select the series (for example, CT or MR) and then drag and drop them to the reference segment onto the inter-vention card.Dragging and dropping onto the refer-ence segment can also be used to load images straight from the scans prior to the intervention.

Frequently Asked Question By Ivo Driesser, Computed Tomography, Siemens Healthcare, Forchheim, Germany

Clinical Workshops 2012 / 2013As a cooperation partner of many leading hospitals, Siemens Healthcare offers continuing CT training programs. A wide range of clinical workshops keeps participants at the forefront of clinical CT imaging.

Workshop Title / Special Interest Date Location Course Director Link

Clinical Workshop on Cardiac CT / Cardiac

Dec, 12 – 14, 2012 Munich, Germany

Siemens Healthcare – Prof. Becker, MD

www.siemens.com/SOMATOMEducate

Clinical Workshop on DE / Dual Energy

Feb, 8 – 9, 2013 Forchheim, Germany

Siemens Healthcare – PD Johnson, MD



Feb, 20 – 22, 2013 Munich, Germany



or 3D sequence scan is performed and then an intervention scan is added. The thin slices from the first scan can easily be used for 3D planning of the interven-tion.Select a 3D layout, select the recon job with the thin slices (Fig. 1, marked in red), and drag and drop them onto one of the MPR segments (Fig. 1). Now it is possible to plan the intervention immediately, for instance to obtain an overview of the situation and anatomical structures.Thus, one extra scan (for example, an i-Spiral) of the affected body area can be eliminated, and therefore less dose is applied. Time can even be saved: by clicking somewhere in one of the three MPR segments there is an automatic

1 Select the recon job with the thin slices (marked in red) and drag and drop them onto one of the MPR Segments. The images from the prior scan can then be used for planning or orientation.

1

* Option


Customer Excellence

Title Dates Short Description Location Contact

Arab Health Jan, 28 – 31 Arab Health Dubai, UAE www.arabhealthonline.com

ECR Mar, 7 – 11 European Society of Radiology Vienna, Austria www.myesr.org

Cardiac MRI & CT Apr, 19 – 21 Cardiac Magnetic Resonance Imaging & Computed Tomography

Cannes, France http://cannes2013.medconvent.at

Africa Health May, 7 – 9 Africa Health Johannesburg, South Africa

www.africahealthexhibition.com

EuroPCR May, 21 – 24 European Association of Percutaneous Cardiovascular Interventions

Paris, France www.europcr.com

esc May, 28 – 31 European Stroke Conference London, England www.eurostroke.eu

ESPR June, 3 – 7 European Society of Paediatric Radiology

Budapest, Hungary

www.espr.org

ESTI June, 8 – 11 European Society of Thoracic Imaging Seoul, Korea www.myesti.org

ISCT June, 17 – 20 International Society for Computed Tomography

Washington DC, USA

www.mdctcourse.com

ECIO June, 19 – 22 European Conference on Interventional Oncology

Budapest, Hungary

www.ecio.org

SCCT July, 11 – 14 Society of Cardiovascular Computed Tomography

Montreal, Canada

www.scct.org

ESC Aug, 31 – Sept, 4

European Society of Cardiology Amsterdam, The Netherlands

www.escardio.org

In addition, you can always find the latest CT courses offered by Siemens Healthcare at www.siemens.com/SOMATOMEducate

Upcoming Events & Congresses 2013

Hands-on Workshop at ECR 2013 / Multiple

Mar, 7 – 11, 2013 Vienna, Austria Siemens Healthcare www.myESR.org

CTA Interpretation Course / Cardiac Mar, 14 – 15, 2013 Erlangen, Germany

Siemens Healthcare – Prof. Achenbach, MD


Hands-on at the ESGAR Workshop / Colonography

Apr, 18 – 20, 2013 Copenhagen, Denmark

ESGAR – P. Lefere, MD C. Lauridsen, MD

www.esgar.org

Hands-on at the ESGAR Congress / Colonography

June, 4 – 7, 2013 Barcelona, Spain

ESGAR – Prof. Carmen Ayuso, MD

www.esgar.org


June, 12 – 14, 2013 Munich, Germany



Oncology Imaging Course 2013 / Oncology

June, 27 – 29, 2013 Dubrovnik, Croatia

OIC – Prof. M. Reiser, MD www.oncoic.org

Customer Excellence



Subscriptions

Siemens Healthcare PublicationsOur publications offer the latest information and background for every healthcare field. From the hospital director to the radiological assistant – here, you can quickly find information relevant to your needs.

For current and past issues and to order the magazines, please visit www.siemens.com/healthcare-magazine.

Medical SolutionsInnovations and trends in healthcare. The magazine is designed especially for members of hospital manage-ment, administration personnel, and heads of medical departments.

MAGNETOM FlashEverything from the world of magnetic reso-nance imaging. The magazine presents case reports, technology, product news, and how-to articles. It is primarily designed for physicians, physicists, and medical technical personnel.

AXIOM InnovationsEverything from the worlds of interventional radiology, cardiology, fluoroscopy, and radiog-raphy. This semi-annual magazine is primarily designed for physicians, physicists, researchers, and medical technical personnel.

eNewsRegister for the global Siemens Healthcare Newsletter at www.siemens.com/healthcare-eNews to receive monthly updates on topics that interest you.

IMAGING LifeEverything from the world of molecular imag-ing innovations. This bi-annual magazine presents clinical case reports, cus-tomer experiences, and product news, and is pri-marily designed for phy-sicians, hospital manage-ment and researchers.

SOMATOM Sessions Online This website is a digital equivalent of the existing print magazine, including news from the world of computed tomography. With its reports and case studies, it is primarily designed for physicians, physicists, and medical technical personnel. www.siemens.com/SOMATOM-Sessions


Imprint

Note in accordance with § 33 Para.1 of the German Federal Data Protection Law: Despatch is made using an address file which is maintained with the aid of an automated data processing system.SOMATOM Sessions with a total circulation of 22,000 copies is sent free of charge to Siemens Computed Tomography customers, qualified physicians and radiology departments throughout the world. It includes reports in the English language on Computed Tomography: diagnostic and therapeutic methods and their application as well as results and experience gained with corresponding systems and solutions. It introduces from case to case new principles and procedures and discusses their clinical potential.The statements and views of the authors in the individual contributions do not necessarily reflect the opinion of the publisher.The information presented in these articles and case reports is for illustration only and is not intended to be relied upon by the reader for instruction as to the practice of medicine. Any health care practitioner reading this information is reminded that they must use their own learning, training and expertise in dealing with their individual patients. This material does not substitute for that duty and is not intended by Siemens Medical Solutions to be used for any purpose in that regard.

The drugs and doses mentioned herein are consistent with the approval labeling for uses and/or indications of the drug. The treating physician bears the sole responsibility for the diagnosis and treatment of patients, including drugs and doses prescribed in connection with such use. The Operating Instructions must always be strictly followed when operating the CT System. The sources for the technical data are the corresponding data sheets. Results may vary.Partial reproduction in printed form of individual contributions is permitted, pro-vided the customary bibliographical data such as author’s name and title of the contribution as well as year, issue number and pages of SOMATOM Sessions are named, but the editors request that two copies be sent to them. The written consent of the authors and publisher is required for the complete reprinting of an article.We welcome your questions and comments about the editorial content of SOMATOM Sessions. Manuscripts as well as suggestions, proposals and information are always welcome; they are carefully examined and submitted to the editorial board for attention. SOMATOM Sessions is not responsible for loss, damage, or any other injury to unsolicited manuscripts or other materials. We reserve the right to edit for clarity, accuracy, and space. Include your name, address, and phone number and send to the editors, address above.

SOMATOM Sessions – IMPRINT© 2012 by Siemens AG, Berlin and Munich All Rights Reserved

Publisher: Siemens AG Medical SolutionsComputed Tomography & Radiation Oncology Siemensstraße 1, 91301 Forchheim, Germany

Chief Editors: Monika Demuth, PhDStefan Ulzheimer, PhD

Clinical Editor:Xiaoyan Chen, MD

Project Management:Miriam Kern, Sandra Kolb

Responsible for Contents:Peter Seitz

Editorial Board:Xiaoyan Chen, MD; Monika Demuth, PhD;Heidrun Endt, MD; Andreas Fischer; Jan Freund; Julia Hölscher; Axel Lorz; Peter Seitz; Stefan Ulzheimer, PhD

Authors of this issue:Hans-Christoph R. Becker, MD, Grosshadern Clinic, Ludwig-Maximilians-University (LMU) Munich, Germany

Zhaoping Cheng, MD, Shandong Medical Imaging Research Institute, Shandong University, Jinan, Shandong, P. R. China

P. Coelho, RT, SAMS Hospital, Lisbon, Portugal

J. Costa, RT, SAMS Hospital, Lisbon, Portugal

Yanhua Duan, MD, Shandong Medical Imaging Research Institute, Shandong University, Jinan, Shandong, P. R. China

Yi Huan, MD, Xijing Hospital, the Fourth Military Medical University, Xian, P.R. China

D. Jesus, RT, SAMS Hospital, Lisbon, Portugal

Xiaopeng Ji, MD, Shandong Medical Imaging Research Institute, Shandong University, Jinan, Shandong, P. R. China

Thorsten R. C. Johnson, MD, Ludwig-Maximilians-University Hospital Munich, Germany

Felix G. Meinel, MD, Ludwig-Maximilians-University Hospital Munich, Germany

Zhen Minwen, MD, Xijing Hospital, the Fourth Military Medical University, Xian, P. R. China

Pei Nie, MD, Shandong Medical Imaging Research Institute, Shandong University, Jinan, Shandong, P. R. China

J. Ramalho, RT, SAMS Hospital, Lisbon, Portugal

P. Oliveira, RT, SAMS Hospital, Lisbon, Portugal

P. G. Pedro, MD, SAMS Hospital, Lisbon, Portugal

L. Pereira, RT, SAMS Hospital, Lisbon, Portugal

H. Pereira, RT, SAMS Hospital, Lisbon, Portugal

Ximing Wang, MD, Shandong Medical Imaging Research Institute, Shandong University, Jinan, Shandong, P. R. China

Martin Wong, Pusat Jantung Hospital Umum Sarawak, Malaysia

Taku Yasumoto, MD, PhD, Toyonaka Municipal Hospital, Osaka, Japan

Qiaowei Zhang, MD, Department of Radiology, Sir Run Run Shaw Institute of Clinical Medicine of Zhejiang University, P. R. China

Shizheng Zhang, MD, Prof., Sir Run Run Shaw Institute of Clinical Medicine of Zhejiang University, P. R. China

Hongliang Zhao, MD, Xijing Hospital, the Fourth Military Medical University, Xian, P. R. China

Irène Dietschi, science and medical writer, Switzerland; Ingrid Horn, PhD, scientific and medical writer, Germany; Eric Johnson, external journalist, Germany; Oliver Klaffke, science and business writer, Switzerland and France; Regina Sailer, PhD, freelance journalist, Austria; Ruth Wissler, MD, scientific and medical writer, Germany

Ana Chaves, RT; Fu Fu Chen, MD; Jiuhong Chen, MD, PhD; Wai Leng Chin; Monika Demuth, PhD; Ivo Driesser; Heidrun Endt, MD; Chenwei Li, MD; Katharina Linseisen; Hong Tao Liu, MD; Katharina Otani, PhD; Andreas Rumpp; Stefan Ulzheimer, PhD; Susanne von Vietinghoff

Photo Credits:plainpicture/fStop; Michael Löwa, Laif; Claude Pauquet, Agence Vu Paris; Stephan Sahm, Laif; Thorsten Rother; Stacy L. Pearsall, Aurora; Kurt Hörbst, Anzenberger; Martin Leissl, Laif; Stephan Sahm, Laif; Miquel Gonzalez, Laif

Production and PrePress: Norbert Moser, Kerstin Putzer, Siemens AG, Healthcare Sector

Reinhold Weigert, Typographie und mehr... Schornbaumstrasse 7, 91052 Erlangen

Proof-Reading: Sheila Regan

Design and Editorial Consulting: Independent Medien-Design, Munich, Germany In cooperation with Primafila AG, Zurich, SwitzerlandManaging Editor: Sonja Waldschuk Photo Editor: Julia BergLayout: Andreas Brunner, Claudia Diem, Mathias Frisch, Heidi Kral, Irina PascenkoAll at: Widenmayerstraße 16, 80538 Munich, Germany

The entire editorial staff here at Siemens Healthcare extends their appreciation to all the experts, radiologists, scholars, physicians and technicians who donated their time and energy – without payment – in order to share their expertise with the readers of SOMATOM Sessions.

On account of certain regional limitations of sales rights and service availability, we cannot guarantee that all products included in this brochure are available through the Siemens sales organization worldwide. Availability and packaging may vary by country and is subject to change without prior notice. Some or all of the features and products described herein may not be available in the United States.

The information in this document contains general technical descriptions of specifications and options as well as standard and optional features which do not always have to be present in individual cases.

Siemens reserves the right to modify the design, packaging, specifications and options described herein without prior notice. Please contact your local Siemens sales representative for the most current information.

Note: Any technical data contained in this document may vary within defined tolerances. Original images always lose a certain amount of detail when reproduced.

The statements by Siemens’ customers described herein are based on results that were achieved in the customer’s unique setting. Since there is no “typical” hospital and many variables exist (e.g., hospital size, case mix, level of IT adoption) there can be no guarantee that other customers will achieve the same results.

Not for distribution in the US.

www.siemens.com/healthcare-magazine

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Siemens AGMedical SolutionsComputed Tomography& Radiation OncologySiemensstraße 191301 Forchheim GermanyPhone: +49 9191 18-0 www.siemens.com/healthcare

Local Contact Information

Asia/Pacific:Siemens Medical SolutionsAsia Pacific HeadquartersThe Siemens Center60 MacPherson RoadSingapore 348615Phone: +65 9622-2026 www.siemens.com/healthcare

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Europe/Africa/Middle East:Siemens AGHealthcare SectorHenkestraße 127D-91052 ErlangenGermanyPhone: +49 9131 84-0 www.siemens.com/healthcare

Latin America:Siemens S.A.Medical SolutionsAvenida de Pte. Julio A. Roca No 516, Piso 7C1067ABN Buenos Aires ArgentinaPhone: +54 11 4340-8400 www.siemens.com/healthcare

USA:Siemens Medical Solutions U.S.A., Inc.51 Valley Stream ParkwayMalvern, PA 19355-1406USAPhone: +1-888-826-9702 www.siemens.com/healthcare

Global SiemensHealthcare Headquarters

Siemens AGHealthcare SectorHenkestraße 12791052 ErlangenGermanyPhone: +49 9131 84-0www.siemens.com/healthcare

Global Siemens Headquarters

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Order No. A91CT-41016-90M1-7600 | Printed in Germany | CC CT 41016 ZS 1112/22. | © 11.2012, Siemens AG

Somatom sessions 31

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Transcript of Somatom sessions 31