Physical Principles and Recent Advances of Medical Imaging...
Transcript of Physical Principles and Recent Advances of Medical Imaging...
AASCIT Journal of Health
2018; 5(1): 21-27
http://www.aascit.org/journal/health
ISSN: 2381-1277 (Print); ISSN: 2381-1285 (Online)
Keywords
Radiology Imaging,
X-Rays,
Radioactive,
X-Photon,
Nuclear Medicine,
CT-Scan,
MRI
Received: February 26, 2018
Accepted: March 15, 2018
Published: April 27, 2018
Physical Principles and Recent Advances of Medical Imaging Systems
Hamidreza Shirzadfar*, Mahtab Khanahmadi
Department of Biomedical Engineering, Sheikhbahaee University, Esfahan, Iran
Email address
*Corresponding author
Citation Hamidreza Shirzadfar, Mahtab Khanahmadi. Physical Principles and Recent Advances of
Medical Imaging Systems. AASCIT Journal of Health. Vol. 5, No. 1, 2018, pp. 21-27.
Abstract
In this paper, a variety of medical imaging systems including Ultrasonography,
MRI, Bone Densitometry, Optical Coherence Tomography, Arthrography, etc. are
reviewed and their advantages and disadvantages are also described. In addition to
these methods, new techniques in medical imaging such as Shear Wave
Elastography and Ultrashort Echo Time are also being reviewed. One of the most
important of these methods is radiology imaging. Radiology is one of a variety of
methods for imaging various parts of the body. Basically, the first assessment of the
patient is radiology. Radiology is a non-invasive and rapid method for diagnosis.
The basis of this method is the ionizer radiation rays. Radiology medicine is divided
into two parts: diagnostic and therapeutic. Radiology medicine based on the energy
used is divided into two types: radiology and nuclear medicine. The basis for the
function of radiology is X-rays and the basis for the performance of nuclear
medicine is radioactive material. Radiology is more dangerous than nuclear
medicine, and is not suitable for pregnant women and children. But radiology is
more accurate and faster than other methods. In addition to its advantages, this
method also includes dangers for the human body. Wilhelm Röntgen was the first
scientist to discover X-rays and record the first radiology image. This paper
describes the components of a radiology device, including a X-ray tube, a
collimator, a detector, and so on.
1. Introduction
Radiology is derived from the word Radius, which means radiation. Ionized rays
in radiology, for diagnosis and treatment [1]. Diagnostic radiology includes
Radiography, Computed Tomography, Mammography and Fluoroscopy, and so on.
Therapeutic radiology is also used for radiation therapy for the treatment of various
types of cancer which includes radiotherapy devices. Electromagnetic spectrum
used for radiology include X-rays, gamma rays, visible light and radio waves. X-
rays can be created by throwing an electron toward an atom [2]. X-rays are divided
into two types, Braking radiation and Characteristic radiation. In Braking radiation,
the electron crosses near the core, and then its speed and energy are changed and
converted to the X-photon. In Characteristic radiation when an electron is thrown
towards the core, it hits one of the electrons and removes it from the orbit. This free
space in the orbit causes energy difference and the release of the X-ray photon [3].
These two types of radiation are shown in Figure 1.
22 Hamidreza Shirzadfar and Mahtab Khanahmadi: Physical Principles and Recent Advances of Medical Imaging Systems
Figure 1. Two types of X-ray radiation [4].
2. Method
In the following, the X-ray generating device, the
radiology device, Nuclear Medicine method and Other recent
of Imaging Methods are described. Also, the advantages and
disadvantages of these methods are also described.
2.1. X-Ray Generating Device
X-ray generating device are different according to their
function. In general, all of them include: X-ray tube (Figure
2), high-voltage generator and control panel.
Figure 2. X-ray tube [5].
One of the important parts of this device is the X-ray tube,
which is an electronic vacuum tube equipped with a cathode
electrode and anode electrode which the cathode is the
negative pole of the tube and the anode is the positive pole of
the tube. The anode is in two forms, fixed and rotating [6].
The fixed type is the Target of Tungsten type which is for
imaging that does not require high power. In the rotating
anode, the Target is a rotating disk of Tungsten type which is
rotated by an electromagnetic induction motor. The reason
for using Tungsten is because it is thermic conductor and has
a high melting point. In an X-ray tube, the cathode infuses
and the electrons are thrown toward the anode, and the
electrons hit the target and X-rays are produced. A high-
voltage generator is designed to produce a potential
difference between the two sides X-ray tube. This part
includes: high-voltage transformer, filament transformer and
rectifier. The control panel is also for controlling the device,
which creates functions for the operator [7].
2.2. Radiology Device
Types of radiological devices include: X-ray tube,
collimator, high-voltage generator, detector, resonator,
control circuit, user's panel and processor device. The
collimator is beam size regulator that has lights and mirrors.
Detector of this device is a radiology film that has a base and
emulsion. These films are an old method for detection, and
today in most countries these images are digitally stored in
databases. Film cassettes have a plate called Grid that is used
to remove irregular beams. The processor is an automatic
device for creating radiology film. Radiological devices are
available in both portable and fixed form. The traditional
radiology has limitations which these limitations include:
time-consuming, high-noise images, low-quality images, and
inability to display at the same time in different locations [8].
Today, with the advancement of technology and the
development of computer systems, two technologies,
Computer Radiology (CR) and Digital Radiology (DR) are
used to detect radiological images. In the CR method, the X-
rays hit a plate of phosphorus, and then read by the scanner
and converted to digital data for computer with the ADC
converter. In the DR method, X-rays hit flat panel detectors,
converted to digital data by an ADC converter, and sent to
the computer for storage. The advantages of these two
technologies, compared to traditional methods, are that they
can be processed before and after recording the results also
have high resolution and high quality images. This
information can be transmitted to other locations by Tele
Radiology system at the same time [9]. One of the most
important uses of radiology is the examination of internal
organs of the abdomen and the digestive tract, diagnosis of
bone fractures, imaging of the lungs, teeth, jaw and face, as
well as the imaging and diagnosis of kidney stones. And also
radiology in therapy to remove tumors and cancer cells [10].
2.2.1. Diagnostic Radiology
Diagnostic radiology for the Diagnosis is a variety of
disorders in the human body, including Radiography,
Computed Tomography, Mammography and Fluoroscopy,
and so on. In radiography, X-rays are exposed to electrical
conditions, and can be diagnosed with various parts of the
body's disease. In simple radiography, external materials are
not required for imaging, but in some cases, the need for
contrast agents is required to detect some tissues.
Consequently, the contrast agents enter the body and then the
imaging is done. In the tomography technique, the X-ray tube
and the detector around the tissue are rotated, then the
imaging is done. Computed Tomography or CT scan,
transmits radiation to the patient's body and is received by
the detectors and convert to the signal and then sent to the
computer. These data are processed by the computer and
displayed. In this method, images are obtained based on the
difference in linear absorption coefficient of the body organ.
Computed Tomography is based on the scan movement, to
different types [11]. Mammography is a method for detecting
abnormal breast changes. In this method, the patient is placed
AASCIT Journal of Health 2018; 5(1): 21-27 23
on the front of the device and the imaging is done. Through
this method, can detect tumors or cancer cells in the breast
[12]. Fluoroscopy method is the simplest method of
radiology. In this method, the patient is placed behind the
fluoroscope and in a short time imaging is done. The
disadvantages of this method are the excessive transmission
of radiation to the patient. This method is used for respiratory
movements of the lung, aperture movements and heart
movements [13].
2.2.2. Therapeutic Radiology
The ionizing rays, by changing the instruction of the atoms
of the human body, causes biological effects in the body.
These rays can also cause cancer and can also treat cancer.
These rays destroy cancerous cells and tumors. These rays
are irradiated relative to the cancerous cell type and the
patient's body physics and measured the amount of radiation
and sent it to the patient according to the required amount
[14].
2.2.3. Advantages of Radiology
The first method for diagnosing diseases is the use of
radiology imaging. This method has a high speed and is very
efficient. This method is very useful in detecting, and the
images that it offers have high contrast and high resolution.
This method is very effective in detecting artery stenosis and
stenting. This method is less costly and easier than other
methods [15].
2.2.4. Disadvantages of Radiology
X-rays produced in this way and radiating to the patient's
body have dangers. These beams are a factor in changing
atoms in the body that cause cancer also cause disorder cell
function. Therefore, this method should not be used too
much. This radiation is very harmful to pregnant women and
causes a genetic mutation in newborns. Therefore, pregnant
women should not use this method as far as possible [16].
2.3. Nuclear Medicine
As previously mentioned, Radiology medicine based on
the energy used is divided into two types: radiology and
nuclear medicine. Imaging is done in nuclear medicine based
on nuclear properties and radioactive materials which the
radioactive radiation used is gamma rays. In nuclear
medicine, visual information is obtained from the metabolic
function of the body. Radiopharmaceuticals used for this
method include isotopes or drugs that are marked with an
isotope. These drugs are injected into the body by
intravaginal injection, subcutaneous injection, oral and
respiration [17]. Instruments used in nuclear medicine
include: Geiger-Muller Counter, Photomultiplier-Tube
(PMT), Absorption Probes, Scintillator Detector, Collimator,
and Dosage Meter. Each of the nuclear medicine devices has
a gamma camera, scanner and electronic circuit X and Y
[18]. Two devices used in nuclear medicine, MRI and CT
scan devices. The methods used for imaging in nuclear
medicine include: (PET) Positron Emission Tomography
[19], Single Photon Emission Computed Tomography
(SPECT), PET-CT, SPECT-CT, SPECT-CT-PET (Figure 3)
and PET-MR.
Figure 3. SPECT-CT-PET imaging system [20].
In the PET method, imaging is based on the detection of
gamma photons created by the destruction of positrons and
electrons. Its function is for neurological diseases and
oncology. Due to the number of crystals and electronic
components, it is more expensive than other methods, and the
number of centers with this method is very few because they
should be alongside an accelerator for isotopes [21]. The
SPECT method is like a PET method, but in the SPECT
method, other radioisotopes are used, and the half-life of
these radioisotopes is higher [22]. The SPECT images show
less detail than the PET method. The SPECT method is less
costly than the PET method, the number of these centers is
high [23]. In the PET-CT combination method, first the CT
scanner is located and then the PET scanner is located. In this
way, 2-dimensional and 3-dimensional images are displayed.
This method is used for neurological diseases, cancer, heart
attacks and epilepsy [24]. In the SPECT-CT method, first the
SPECT scanner is located and then the CT scanner is located.
In this method, the applied information from the SPECT and
the anatomical information from CT are obtained, and then
this information is combined together. In this combination
method, CT data is used to modify the SPECT data [25]. The
PET-MR method, the PET scanner, is located inside the MRI
device, and the imaging is done simultaneously. The pet's
device uses PMT. Because PMT is sensitive to the magnetic
field, in this combination method with MRI, other detectors
are used instead of PMT. These alternative detectors include:
Avalanche photodiode and silicon photomultiplier. The
function of nuclear medical devices includes bone scan, heart
scan, thyroid scan, lung perfusion scan, lung ventilation scan,
and brain perfusion scan [26].
2.4. Other Recent of Imaging Methods
Ultrasonography is one of the most common methods of
imaging. In this method ultrasonic waves are sent by the
probe to the patient's body, and then these waves hit the
target tissue and are reflected and received by the receiver
and an image is displayed on the monitor. This method is
most useful for examining the condition of the fetus, uterus,
and ovaries. This method is safe and does not pose a risk to
the fetus [27].
Bone densitometry is another method of imaging. In this
24 Hamidreza Shirzadfar and Mahtab Khanahmadi: Physical Principles and Recent Advances of Medical Imaging Systems
method, the severity of the bones of the body is measured.
This type of imaging is for people who are exposed to
osteoporosis [28]. Several methods are available, but the
most commonly used method is Dual Energy X-ray
Absorptiometry (DEXA). In this method, two x-ray tubes are
used for radiation to the bone. The higher the bone density,
the greater the amount of radiation absorbed. The beam
received by the detector is transferred to the computer, where
processing and calculation are performed. The reason is the
use of two sources for more accurate measurement. In this
method, two types of environmental scanners and central
scanners are used [29].
Magnetic Resonance Imaging (MRI) is another imaging
method. In this way, instead of X-rays, radio waves and
magnetic waves are used, and therefore they do not pose a
risk to the human body. The patient is placed in a magnetic
field and then the radio waves are emitted to the patient's
body. Then the reflected waves of the patient's body are
analyzed by the computer. Compared with the CT scan
method, this method is purely for imaging soft tissues such as
tendons, veins, nerves and cartilage in the body. But the CT
scan is more commonly used to examine bone problems. In
some cases, the drug is injected into the patient before doing
the imaging. In this method, the patient must remove all the
metal devices because they are absorbed by the magnetic
field. Therefore, people who have implants or pacemakers
cannot use this method [30].
Venography is one of the complementary methods of
radiology that the contrast agents are injected into the arteries
or veins [31]. Then x-rays are radiating to the body. With this
method, blood clots in the main vessels can be detected [32].
Myelography is also one of the complementary methods of
radiology. In this method, the contrast agent is injected into
the patient's spinal cord, and X-rays are irradiated. This
method is used to detect the pressure of the disk on the spinal
cord and the neural roots [33].
In Arthrography, a contrast agent is injected with the air
into the joints and x-rays are radiating to the body. This
method is used to detect cruciate ligament and meniscus
damage and rupture of the rotator cuff shoulder [34].
Shear Wave Elastography (SWE) is one of the newest
methods in medical imaging. Due to the fact that the
elasticity of the healthy and unhealthy tissues is different, it
is possible to detect unhealthy tissues on this basis. This type
of method is based on tissue consistency [35]. In this method,
the liver chronic masses are examined without the need for
sampling and non-invasive. This method can detect the
severity of tissue damage in hepatitis and liver fibrosis. This
method can also be used to evaluate malignant tumors in the
thyroid, breast, and prostate [36]. Diagnosis of fatty liver
with SWE method is shown in figure 4.
Figure 4. Diagnosis of fatty liver with Shear Wave Elastography method [37].
AASCIT Journal of Health 2018; 5(1): 21-27 25
THz imaging is based on terahertz waves. This method has
two fundamental types: Transmission Based and Reflection
Based. This method is used to diagnose skin cancer, breast
cancer and corneal moisture measurement. The Optical
Coherence Tomography method is a cross-sectional
methodology that is the basis of its optical interferometry.
This method creates 3-dimensional images [38].
Another method is Ultrashort Echo Time (UTE). This
method is one of a variety of MRI methods. The echo time is
the time between the frequency radio pulse and the peak sent
in the coil. This is a method for recording lung parenchymal.
Using this method, it can display complete lung anatomy and
detect pulmonary disorders. This method is without ionizing
radiation, so there is no danger and is therefore more
appropriate than CT scan [39]. This method creates 2-
dimensional and 3-dimensional images [40, 41]. The image
taken from the lungs, at different echo times, is shown in
Figure 5.
Figure 5. The image taken from the lungs with UTE method, at different echo times [42].
3. Result
Initially, a radiology device, including a X-ray tube, a
collimator, a detector, a high-voltage generator, resonator,
etc., was described. The X-ray generator is responsible for
producing x-rays using two anode and cathode electrodes.
The collimator also adjusts the size and radius of the beam
and radiology films are detectors of this device. Radiological
device in diagnostic and therapeutic fields. Radiology is
harmful for the human body because of the use of X-rays, but
more accurate and faster than other methods. In nuclear
medicine, imaging is performed based on nuclear properties
and radioactive material. Also, Instruments used in nuclear
medicine include: Geiger-Muller Counter, Photomultiplier-
Tube (PMT), Absorption Probes, Scintillator Detector,
Collimator, and Dosage Meter. Imaging based on nuclear
medicine involves various methods that each of them has
different advantages and disadvantages.
4. Discussion
Radiology method is based on X-rays and a nuclear
medicine method based on radioactive material. Radiology is
very dangerous for pregnant women due to the use of
ionizing radiation and causes a genetic mutation in the fetus.
The methods used for imaging in nuclear medicine include:
(PET) Positron Emission Tomography, Single Photon
Emission Computed Tomography (SPECT), PET-CT,
SPECT-CT, SPECT-CT-PET and PET-MR. An
Ultrasonography method is based on ultrasound that enters
the body by the probe. Bone densitometry is used to measure
the degree of bone hardness that is based on X-rays. The
MRI imaging method is based on magnetic field resonance s
that do not have the harm caused by ionizing radiation. In the
Shear Wave Elastography method, based on the elasticity of
the tissue, it can detect unhealthy tissue that is most
commonly used for liver disease. Ultrashort Echo Time is an
MRI imaging technique used to record parenchymal lung.
26 Hamidreza Shirzadfar and Mahtab Khanahmadi: Physical Principles and Recent Advances of Medical Imaging Systems
5. Conclusion
In this paper, types of imaging methods have been
investigated. One of the most important of these methods is
radiology imaging that is faster and more accurate than other
methods. But this method has some disadvantages due to the
use of X-rays. This method is very dangerous for pregnant
women and children. In nuclear medicine, nuclear properties
and radioactive materials are used. Radioactive material is
also harmful to the body, but its intensity is less than that of
X-rays. Methods that are based on the Magnetic field
intensification spend more time than the radiological method
but do not have the dangers of ionizing radiation. In this
method, all metal objects and objects that are sensitive to the
magnetic field should be away from the patient at the time of
imaging. These imaging methods are diagnostic and
therapeutic. These imaging methods are invasive and non-
invasive. Some imaging techniques require contrast agents to
display the tissue properly. All the methods described have
advantages and disadvantages each of which, according to
their function, are used in various diseases.
References
[1] Yurt, A., Çavuşoğlu, B., Günay, T. (2014): GünayEvaluation of Awareness on Radiation Protection and Knowledge About Radiological Examinations in Healthcare Professionals Who Use Ionized Radiation at Work. Molecular Imaging and Radionuclide Therapy. Vol. 23, Issue 2 Pg 48-53.
[2] Shapiro, D. A., et al. (2014): Chemical composition mapping with nanometre resolution by soft X-ray microscopy. NATURE PHOTONICS. Vol. 8, Pg 765-769.
[3] Zmarz Ly, D., Nagi, L., Borucki, S., Boczar, T. (2014): Analysis of Ionizing Radiation Generated by Partial Discharges. ACTA PHYSICA POLONICA. Vol. 125, Issue 6 Pg 1377-1379.
[4] http://www.physics.isu.edu/health-physics/tso/rad_training/ussalpha.html
[5] https://radiologykey.com/the-x-ray-tube-2/
[6] Maire, E., Withers, P. J. (2014): Quantitative X-ray tomography. International Materials Reviews. Vol. 59, Issue 1 Pg 1-43.
[7] Nasseri, M. M. (2016): Determination of tungsten target parameters for transmission X-ray tube-A simulation study using Geant 4. Nuclear Engineering and Technology. Vol. 48, Issue 3 Pg 795-798.
[8] Koukorava, C., Farah, J., Struelens, L., Clairand, I., Donadille, L., Vanhavere, F., Dimitriou, P. (2014): Efficiency of radiation protection equipment in interventional radiology: a systematic Monte Carlo study of eye lens and whole body doses. Journal of Radiological Protection. Vol. 34, Issue 3 Pg 509-528.
[9] European Society of Radiology. (2014): ESR white paper on teleradiology: an update from the teleradiology subgroup. Springer. Insights into Imaging. Vol. 5, Issue 1 Pg 1-8.
[10] Meidanchi, A., Akhavan, O., Khoei, S., Shokri, A., Hajikarimi, Z., Khansari, N. (2015): ZnFe2O4 nanoparticles as
radiosensitizers in radiotherapy of human prostate cancer cells. Science Direct. Materials Science and Engineering C. Vol. 46, Pg 394-399.
[11] Tekin, H. O., Manici, T., Ekmekci, C. (2016): Investigation of Backscattered Dose in a Computerized Tomography (CT) Facility during Abdominal CT Scan by Considering Clinical Measurements and Application of Monte Carlo Method. Journal of Health Science. Vol. 4, Pg 131-134.
[12] Damases, C. N., Brennan, P. C., McEntee, M. F. (2016): Mammographic density measurements are not affected by mammography system. Journal of Medical Imaging. Vol. 2, Issue 1 Pg 1-5.
[13] Guan, Sh., Gray, H. A., Keynejad, F., Pandy, M. G. (2016): Mobile Biplane X-Ray Imaging System for Measuring 3D Dynamic Joint Motion During Overground Gait. IEEE TRANSACTIONS ON MEDICAL IMAGING. Vol. 35, Issue 1 Pg 326-325.
[14] Park, B., Yee, C., Mi Lee, K. (2014): The Effect of Radiation on the Immune Response to Cancers. International Journal of Molecular Sciences. Vol. 15, Issue 1 Pg 927-943.
[15] Dettmer, S., Weidemann, J., Fischer, V., Wacker, F. K. (2015): Integrative Teaching in Radiology – A Survey Integrative Lehre in der Radiologie – eine Bestandsaufnahme. Academic Radiology. Vol. 187, Pg 260-268.
[16] Autsavapromporn, N., et al. (2015): Genetic changes in progeny of bystander human fibroblasts after microbeam irradiation with X rays, protons or carbon ions: The relevance to cancer risk. International Journal of Radiation Biology. Vol. 91, Issue 1 Pg 62-70.
[17] Lecouvet, F. E., er. (2014): Monitoring the response of bone metastases to treatment with Magnetic Resonance Imaging and nuclear medicine techniques: A review and position statement by the European Organisation for Research and Treatment of Cancer imaging group. ScienceDirect. European Journal of Cancer. Vol. 50, Issue 15 Pg 2519-2531.
[18] Saha, G. B. (2017): Instruments for Radiation Detection and Measurement. Fundamentals of Nuclear Pharmacy. Pg 33-47.
[19] Matthies, Ph., Gardiazabal, J., Okur, A., Vogel, J., Lasser, T., Navab, N. (2014): Mini gamma cameras for intra-operative nuclear tomographic reconstruction. Medical Image Analysis. Vol. 18, Issue 8 Pg 1329-1336.
[20] http://www.mediso.hu/products.php?fid=1,9&pid=69
[21] Ariza, M., Kolb, H. C., Moechars, D., Rombouts, F., Andrés, J. I. (2015): Tau PET Imaging: Past, Present and Future. Journal of Medicinal Chemistry. Vol. 58, Issue 11 Pg 4365-4382.
[22] Zhu, L., Ploessl, K., Kung, H. F. (2014): PET/SPECT imaging agents for neurodegenerative diseases. Chemical Society Reviews. Vol. 43, Issue 19 Pg 6683-6691.
[23] Andrzejewska, A., Nowakowski, A., Janowski, M., Bulte, J., Gilad, A., Walczak, P., Lukomska, P. (2015): Pre- and postmortem imaging of transplanted cells. International Journal of Nanomedicine. Vol. 10, Pg 5543-5559.
[24] Kolthammer, J. A., Hao Su, K., Grover, A., Narayanan, M., Jordan, D. W., Muzic, R. F. (2014): Performance evaluation of the Ingenuity TF PET/CT scanner with a focus on high count-rate conditions. Institute of Physics and Engineering in Medicine. Vol. 59, Pg 3843-3859.
AASCIT Journal of Health 2018; 5(1): 21-27 27
[25] Bailey, D. L., Willowson, K. P. (2014): Quantitative SPECT/CT: SPECT joins PET as a quantitative imaging modality. Eur J Nucl Med Mol Imaging.
[26] Wehrl, H. F., Sauter, A. W., Divine, M. R., Pichler, B. J. (2015): Combined PET/MR: a Technology Becomes Mature. Journal of Nuclear Medicine. Vol. 58, Issue 2 Pg 165-168.
[27] Chung, Y. E., Kim, K. W. (2014): Contrast-enhanced ultrasonography: advance and current status in abdominal imaging. Ultrasonography. Vol. 34, Issue 1 Pg 3-18.
[28] Knapp, K. M., Welsman, J. R., Hopkins, S. J., Shallcross, A., Fogelman, I., Blake, G. M. (2014): Obesity Increases Precision Errors in Total Body Dual-Energy X-Ray Absorptiometry Measurements. Journal of Clinical Densitometry: Assessment & Management of Musculoskeletal Health. Pg 1-8.
[29] Nana, A., Slater, G. J., Stewart, A. D., Burke, L. M. (2014): Methodology Review: Using Dual-Energy X-Ray Absorptiometry (DXA) for the Assessment of Body Composition in Athletes and Active People. International Journal of Sport Nutrition and Exercise Metabolism. Vol. 24, Pg 198-215.
[30] Joseph, R. P., Singh, C. S., Manikandan, M. (2014): BRAIN TUMOR MRI IMAGE SEGMENTATION AND DETECTION IN IMAGE PROCESSING. International Journal of Research in Engineering and Technology. Vol. 3, Issue 1 Pg 1-5.
[31] Houshmand, S., Salavati, A., Hess, S., Ravina, M., Alavi, A. (2014): The role of molecular imaging in diagnosis of deep vein thrombosis. Am J Nucl Med Mol Imaging. Vol. 4, Issue 5 Pg 406-425.
[32] Peshkova, A. D., Malyasev, D. V., Bredikhin, R. A., Giang, L. M., Litvinov, R. I. (2016): Contraction of Blood Clots Is Impaired in Deep Vein Thrombosis. Springer Science. Vol. 6, Issue 4 Pg 457-459.
[33] Yoshii, T., et al. (2014): Dynamic Changes in Spinal Cord Compression by Cervical Ossification of the Posterior Longitudinal Ligament Evaluated by Kinematic Computed Tomography Myelography. CERVICAL SPINE. Vol. 39, Issue 2 Pg 113-119.
[34] Sebro, R., Oliveira, A., Palmer, W. E. (2014): MR Arthrography of the Shoulder: Technical Update and Clinical Applications. Semin Musculoskelet Radiol. Vol. 18, Issue 4 Pg 352-364.
[35] Saldera, K., Naqvi, N. F., Mahmood, T., Shaikh, S. S. (2016): SHEAR WAVE ELASTOGRAPHY; ASSESSMENT OF LIVER FIBROSIS IN A PATIENT OF CHRONIC LIVER DISEASE ASSOCIATED INFECTED BY HEPATITIS B AND C. The Professional Medical Journal. Vol. 23, Issue 1 Pg 99-103.
[36] Ferraioli, G., Parekh, P., Levitov, A. B., Filice, C. (2014): Shear Wave Elastography for Evaluation of Liver Fibrosis. American Institute of Ultrasound in Medicine. Vol. 23, Pg 197-203.
[37] https://www.auntminnieeurope.com/index.aspx?sec=ser&sub=def&pag=dis&ItemID=613216
[38] Ouchi, T., Kajiki, K., Koizumi, T., Itsuji, T., Koyama, Y., Sekiguchi, R., Kubota, O., Kawase, K. (2014): Terahertz Imaging System for Medical Applications and Related High Efficiency Terahertz Devices. Springer Science. Vol. 35, Issue 1 Pg 118-130.
[39] Burris, N. S., Johnson, K. M., Larson, P. E. Z., Hope, M. D., Nagle, S. K., Behr, S. C., Hope, T. A. (2015): Detection of Small Pulmonary Nodules with Ultrashort Echo Time Sequences in Oncology Patients by Using a PET/MR System. TECHNICAL DEVELOPMENTS. Pg 1-8.
[40] Delso, G., Carl, M., Wiesinger, F., Sacolick, L., Porto, M., Hüllner, M., Boss, A., Veit-Haibach, P. (2014): Anatomic Evaluation of 3-Dimensional Ultrashort-Echo-Time Bone Maps for PET/MR Attenuation Correction. THE JOURNAL OF NUCLEAR MEDICINE. Vol. 55, Issue 5 Pg 780-785.
[41] Shirzadfar, H. (2014). Conception et réalisation d'un biocapteur à GMR pour la caractérisation de milieux biologiques (Doctoral dissertation, Université de Lorraine).
[42] https://www.itnonline.com/content/toshiba-introduces-ultrashort-echo-time-sequence-pulmonary-mr-imaging