Solving Medical Mysteries with Imaging Richard S. Breiman, M.D. Professor of Radiology and Biomedical Imaging (Medical Imaging Detective) UCSF The Medical Imaging Detective Peering into the Patient to Solve Mysteries Role in Patient Care History of Radiology Imaging Tools Radiologist s Method Cases Non-Medical Applications Discussion What Does a Radiologist Do? Radiology Subspecialities 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 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 X-ray Art Historical Investigation Image Mummies, Artifacts Study Prehistoric Creatures History of Radiology 1895: X-rays discovered by W.C. Roentgen, Nobel Prize 1901 Edison develops the intensifying screen (& explores nonmedical 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
Liver Kidney Diaphragm Spleen Stomach Psoas M 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 Pixel=X+Y CT: Volume Data Isotropic Data: X=Y=Z Voxel=X+Y+Z 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 Hounsfield # s (HU) CT # s
Higher Quality & # of Images Volume Rendering Manipulate Color Opacity Perspective Cut Planes Movement Digital Access Volume Rendering Manipulate Color Opacity Perspective Cut Planes Movement Digital Access 3D Applications in Diagnosis 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 of Complex Pelvic Fractures Virtual Colonoscopy (CT) 3D Applications Simulation & Guidance of Invasive Procedures Ruptured Aneurysm 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.
The Radiologist s Method Create & Manipulate Data (Medical Images) Search for Clues Analyze Findings Communicate Results The Radiologist s Method Create 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 Method Systematic 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 Method Analysis 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 Method Communication 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 Cancer Extent? 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 - 99m Tc Thyroid scan - I 131 Liver scan - 99m Tc 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 Radiology Pancreatitis Drainage for Diagnosis & Therapy Thank You! Richard S. Breiman, MD