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