The Medical Imaging Detective Solving Medical Mysteries...
Transcript of The Medical Imaging Detective Solving Medical Mysteries...
Richard S. Breiman, M.D.Professor of Radiology and
Biomedical Imaging(Medical Imaging Detective)
UCSF
Solving Medical Mysteries with
Imaging
The Medical Imaging Detective
• Role in Patient Care
• History of Radiology
• Imaging Tools
• Radiologist’s Method
• Cases
• Non-Medical Applications
• Discussion
Peering into the Patient to Solve Mysteries
What Does a Radiologist Do?
• Designs & Monitors Exams• Interprets Exams for Dx & F/U• Communicates Results, Consults with Clinicians• Performs Interventions for Dx or Rx
• Percutaneous biopsy, drainage (abscess, etc)• Tumor ablation (kill tumor) • Open obstructed ducts and vessels• Embolize bleeding vessels, aneurysms, vascular
malformations, tumor blood supply
Radiology Subspecialities•Neuroradiology•Thoracic Imaging
•Pulmonary•Cardiac
•Abdominal Imaging•Gastrointestinal•Genitourinary
•Musculoskeletal Imaging
•Vascular Imaging•Interventional Radiology
•Pediatric Imaging•Women’s Imaging
•Breast•OB/GYN
•Nuclear Medicine•Radiation Oncology •Molecular Imaging •Future new fields
dependent on technology development
Non-Medical Applications
• Industrial Applications • Forensic Medicine• Historical Investigation• Image Mummies, Artifacts
• Study Prehistoric Creatures• X-ray Art
History of Radiology
• 1895: X-rays discovered by W.C. Roentgen, Nobel Prize 1901
• Edison develops the intensifying screen (& explores non-medical applications of X-ray tube: light bulb, photography)
• 1896: 1st (accidental) application of X-ray for therapy, deliberate XRT 1898
• Early 1900’s: Tube & intensifier developments, methods for opacification
• 1971: Godfrey Hounsfield invents CT, 1st computer-based imaging, Nobel Prize
The Appearance of Materials and Tissues on X-ray Depends on the Amount of X-rays they Absorb
Abdominal X-Ray
Diaphragm
Liver Spleen
Kidney
Psoas M
Stomach
Radiology Developments Prior to Computer-based Imaging
• Improved X-ray tubes & films
• Fluorescent screens, image intensifiers
• Automated film developers
• Large viewboxes, alternators
• Fluoroscopy: real-time X-ray
• Contrast to opacify structures: Oral, Rectal, Injected
Computer-based Medical Imaging The Radiology Detective’s Tools
• Powerful Imaging Exams: X-ray, CT, US, MR, NM (PET/CT), Interventional Techniques & Hardware
• PACS: Digital Archival, Retrieval & Display System
• Computer Workstations for Interpretation & Review: display, manipulation, comparison, editing, demonstration
• Voice Activated Transcription for Rapid Reports
• Remote Access (Teleradiology):
• LAN: Department, Clinics, Surgery, Regional Facilities
• WAN: Distant Facilities, Mobile, Patient CD’s
CT: Technological Advancements• Cross-sectional
• Eliminates problem of overlying dense structures obscuring less dense structures
• Utilizes detectors rather than film
• Distinguish tissues by X-ray absorption
• Digital data
• Image processing
• Digital archive
• Transmission of scans
CT: Volume Data Isotropic Data: X=Y=Z
Pixel=X+Y Voxel=X+Y+Z
Hounsfield #’s (HU)CT #’s
The Appearance of Materials & Tissues on CT
Depends on the Amount of X-rays they Absorb
The Appearance of Materials & Tissues on CT
Depends on the Amount of X-rays they Absorb
Higher Quality & # of ImagesVolume Rendering
Manipulate•Color•Opacity•Perspective•Cut Planes•Movement•Digital Access
Volume RenderingManipulate•Color•Opacity•Perspective•Cut Planes•Movement•Digital Access
• Improved detection of subtle abnormalities• More efficient review of large datasets• Improved confidence• Better communication of results to physicians & patients
• Demonstrate findings with fewer images• Easier to understand complex anatomy
3D Applications in Diagnosis
3D of Complex Pelvic Fractures Virtual Colonoscopy (CT)
• Simulation• Procedure planning• Pre-op practice• Reduce complications?
• Intra-operative guidance• Instrument position & imaging anatomy correlation• Robotic surgery• Remote procedures - performed by distant
specialist - battlefield for eg.
3D ApplicationsSimulation & Guidance of Invasive Procedures
Ruptured Aneurysm
The Radiologist’s Method
• Create & Manipulate Data (Medical Images)
• Search for Clues
• Analyze Findings
• Communicate Results
The Radiologist’s MethodCreate Data
• Select Appropriate Exam
• Assess Risk vs. Reward
• Minimize cost, radiation and risk where possible
• Design Appropriate Exam Protocol
• Monitor/Modify Exam
The Radiologist’s MethodSystematic Review of Images
• Display & Manipulate Images
• Search for Clues (Findings)
• Related to Clinical Problem
• Related to Other Significant Problem
• Incidental Findings
"It has long been an axiom of mine that the little things are infinitely the most important" Sherlock Holmes in A Case of Identity
The Radiologist’s MethodAnalysis
• Correlate with Clinical Presentation
• Assess Stability
• Determine Effect on Management & Urgency
• Determine if Results are Adequate or if Additional Exams Needed
• For Diagnosis
• For F/U
The Radiologist’s MethodCommunication of Results
• Dictate Report
• Conversation with Provider
• Communicate Urgent Results Effecting Management
• Correlate Clinical & Imaging Findings
• Assess Significance
• Patient Access to Results
• Report, CD
• Discussion, Educate
Radiology Workstation
65 yo Woman with Abdominal Pain 65 yo Woman with Abdominal Pain
Smoker: Difficulty Breathing Left Flank Pain + Hematuria - Why?
Left Adrenal Gland CancerExtent? Ultrasound
• High frequency sound
• Sound reflected back to probe
• Appearance depends on tissue characteristics + distance
• Real-time
• Doppler - Blood flow
• Intra-cavitary probes
• Air, calcium block sound
• Cyst vs. solid, abdominal & pelvic organs, vessels, biopsy guide
Magnetic Resonance• Magnetic field aligns nuclei, RF flips
nuclei, RF off, returning RF signal detected by an antenna
• No radiation, expensive, long exams, claustrophobia
• Good tissue discrimination
• Brain, spine, abdominal, pelvic organs, vessels
• Not good for air, movement
• MR Imaging (MRI)
• MR Spectroscopy (MRS)
• Assess quantity of creatine, choline, citrate
MR - Glial Tumor
T1 T2
Nuclear Medicine
• Radionuclide injected, accumulates in organs or tumor, emits radioactivity
• Whole body survey
• Limited anatomic detail
• Bone scan - 99mTc
• Thyroid scan - I131
• Liver scan - 99mTc
• Positron Emission Tomography (PET) + CT PET/CT - 18-FDG accumulates in areas of increased metabolism (certain tumors)
• Brain, head & neck, lung ca, colon ca, breast ca, lymphoma, melanoma
PET/CT
• Detect malignant foci
• Often before other imaging exams
• Direct attention to possible imaging abnormality
• Determine significance of imaging findings
• Assess success of therapy or detect recurrence
• May miss small (<5mm) malignant foci
• Not all FDG avid foci are malignant or even abnormal
Interventional RadiologyPancreatitis
Drainage for Diagnosis & Therapy
Thank You!
Richard S. Breiman, MD