Transition to Clerkship – Radiology

1. Transition to Clerkship – Radiology Marc Gosselin, MD

2. What Penguins Fell Off The Iceberg Since We Last Meet?

3. Introduction:‘Medicine is the Science of Uncertainty and the Art of Probability’ – Sir William Osler • Goals • ·Become familiar with and practice using the webPACS system • ·Gain a basic approach to interpreting chest images • ·Gain a basic approach to interpreting bone images • ·Understand the use of the abdominal film • ·Understand the use of contrast • ·Understand practical issues with MRI

4. Key Points • ·  Understand the need for clinical information when ordering and interpreting radiological studies • ·  Understand how consultation with a radiologist before you order a study can help get the proper study • ·  Try to learn about the tests that you are ordering your patient to experience during your rotations. You may never have another chance!

5. BEWARE:The ‘Diamond Algorithm’ is Very Common! Do NOT Be Fooled!

6. Basics for Radiology • Contrast • MRI • Web sites • Images into a presentation

7. Contrast Contrast for x-ray related images is either: Iodinated Barium or Omni for Gastrointestinal tract Contrast for MRI is gadolinium based Some newer experimental agents are iron based.

8. Contrast What it’s used for • Vessels • Tumor detection • Infection detection • Better anatomic detail

9. Contrast- When to order • Brain (1st ? to ask - CT or just order MRI) • Looking for tumor • Infection • Spine • Rarely need • Canal infection (epidural abscess, MRI better choice) • Minimal use in “bone” tumors/mets • Chest, Neck, Abd, pelvis • Very helpful and usually used (except Chest) • Musculoskeletal system • Ask Radiologist • Mainly if need to know about vessels

10. Contrast - Risks • Risk of death, at worst 1 in 130,000 • Renal failure, stroke, other severe reaction is low as well • Contrast Induced Nephropathy may be more common than previously thought

11. Contrast – Risks – Allergy? • Reaction to iodinated contrast agents are not true allergies • too small of agent to act as antigen • no antibodies ever detected • Even if the patient has had a previous reaction, unlikely to have a reaction the next time • Although a prior reaction remains the best predictor of a future adverse event, the likelihood is in the range of 8 – 25% • If it were a true allergy the risk should approach 100%

12. Contrast – Risks – Allergy? • Other allergies or asthma • Only minimally predicts an increase risk • Not a reason to avoid injection • Asthma only predicts bronchospasm and then only in active asthma cases • Allergy to shellfish is not a predictor (organic iodine)

13. Contrast-Induced Nephropathy • Mainly a risk if there is some underlying compromise of renal function • BUN as a guide to state of hydration • Creatinine as a guide to whether there is true dysfunction • Better test is creatinine clearance (calculated) Alice Mitchell, MD et al: ACADEMIC EMERGENCY MEDICINE 2012; 19:618–625

14. Nephropathy – Risk Factors • Diabetes • Recurrent renal stones • Recurrent UTI • Hx of bladder outlet obstruction • Recent events • Major surgery • Dehydration!! (Adequate hydration prior and afteradministration is 1st step to prevent nephrotoxicity) • Cardiogenic shock • Other nephrotoxic agents • Gentamycin etc. • High-dose nonsteroidals • Certain chemotherapy agents

15. Contrast – Risks – Allergy? • Prior contrast reactions • Urticaria to anaphylactoid process • Use different agent (low osmolality, nonionic isotonic dimmer (iodixanol)) • Have equipment and expertise available to treat • Pre-medicate with corticosteroids and/or antihistamines • Prevents minor reactions • Not enough data to know if it prevents life-threatening reactions

16. MRI Safety • Who can and can’t get scanned • What are the risks • What is the cost • What things to think/worry about • Bottom line – risk vs. benefit vs. cost

17. Metal Ferromagnetic Non-ferromagnetic Location Orbit Vessels/heart Bones Brain Other Implantable devices Pacemakers, ICDs Pumps, stimulators Wires, lines Heart Valves Aneurysm clips Intravascular coils, filters, & stents MRI Safety Issues

18. MRI – other considerations • Claustrophobia • Noise • Heating (SAR – specific absorption rate) • Tattoos & permanent cosmetics • Pregnancy and Breast feeding • Magnetic Field Strength

19. Web Sites • American College of Radiology Appropriateness Criteria • www.acr.org/dyna/?doc=departments/appropriateness_criteria/text.html • UpToDate (I Call it ‘FOX NEWS’) • www.uptodate.com • The Number Needed to Treat • www.nnt.com • OHSU Medical Student page • http://sunweb1.ohsu.edu/radiology/med/

20. Web Sites • Virginia Web Site (sections on head CT, Cervical spine, ICU chest film, ER body CT, Skeletal Trauma) • http://www.med-ed.virginia.edu/courses/rad/ • Virtual Hospital, Introduction to Abdominal Radiology.http://www.vh.org/Providers/Lectures/icmrad/abdominal/Abdominal.html • University of Washington, Radiology Review:http://uwcme.org/site/courses/legacy/threehourtour/

21. 3rd Year Tips • Always try to helpful, in any way • Search for evidence on the disease or treatment regarding your patients each day • Give presentations with literaturefrom different specialties…good career habit! • Try to refer back to your basic science classes as much as possible! (Don’t throw your books away) • Don’t rock the boat…at least not yet! (There are serious “land mines” out there for students…watch your step, watch what you say!)

22. 3rd Year Tips • Generate Questions (to Yourself) Every day! • Generate Options for Work up or Therapy Every day (to Yourself) • Do NOT ‘Marry’ ANY Medical ‘Fact’ (Dogma) or ‘Standard of Care’! Watch out for ‘They say…’ or ‘Everybody knows…’ • Be Outraged (Quietly) When You see any of this: (I’ll likely get Vocal - you don’t…yet)

23. White Zinfandel is NOT a wine!

24. Scout for a CT of the “Head, Chest, Abdomen, Pelvis and Complete Spine”Has some abdomen and low back pain…Primary & Secondary Survey were ‘Done’