Introduction to Radiology

1. Introduction to Radiology Casey Sams, MD

2. Introduction to Radiology • I: Radiology • Who we are • What we do • Our tools • How can you help us help you • II: Contrast • III: Plain Film Imaging of the Abdomen • IV: Radiology at UNC • V: Parting Thoughts

3. Definition of Radiology • Radiology is a medical specialty using medical imaging technologies to diagnose and treat patients.

4. So what does this mean? • We do NOT spend all day in a small dark room staring at a computer screen ….just most of the day

5. A widely varied discipline • Read a chest x ray • Stage lymphoma • Do a TIPS procedure • Do a biopsy (lung, bone, thyroid, breast…) • Inject a joint • Do a barium swallow

6. With multiple subspecialties • Breast • Body • Neuro • MSK • Peds • IR

7. What our are tools? • X-rays • CT • MRI • Ultrasound • Nuc Medicine • Fluoroscopy • Mammography

8. Conventional Radiography “X-Ray” • Lingo: • Density • Opacity • Observable Densities: • Metal • Bone • Soft Tissue • Gas

9. Computed Tomography (CT) • Lingo: • Attenuation • Density • Enhancement • Hounsfield Units • -1000 air *** • -100 fat • 0 water *** • 20-80 soft tissues • 100’s bone/Ca/contrast • >1000’s metal • Large radiation dose

11. Nuclear Medicine (NM) • Lingo: • Counts or Activity • Physiologic imaging • Radionuclides • (Technetium) • Radiopharmaceuticals • (Choletec) • Radioactivity stays with the patient until cleared or decayed

12. Ultrasound • Lingo • Echogenicity • Shadowing • Doppler for flow • No radiation • Can be portable • Relatively inexpensive

13. Magnetic Resonance Imaging (MRI) • Lingo: • Signal intensity • T1 • T2 • Enhancement • No radiation • Strong magnetic field • No pacemakers • No electronic implants • Small, loud tube • Patients must hold still • Relatively expensive

14. Fluoroscopy • Lingo • Filling defect • Density • Opacity • Real time information • Radiation dose dependent on length of exam http://www.med-ed.virginia.edu/courses/rad/gi/index.html

15. Mammography http://www.mdgrant.com/images/NormalMammogram.jpg • Lingo • Microcalcifications • Mass • Asymmetric density • Screening exam consisting of 2 views recommended yearly for women over 50 • We still recommend it!

16. When will you interact with Radiology? • Anytime you read a report on a study • As a part of rounds (critical care and ID rotations in particular) • When we call you up to ask about more information before we do a study • When you call us to ask about which study should be done

17. And if you want more… • Rad 401 elective is a great way to get a broad introduction to radiology. Very helpful for people not interested in pursuing a career in radiology (plus those who are!) • Pediatric radiology rotation • Neuroradiology rotation • Choose your own adventure….

18. How can you help us help you? • Indication, indication, indication • How will this study impact your clinical decision making? If it won’t, perhaps its useful to rethink the need for the study. • Become adept at how to read basic studies (chest and abdominal films for line and tube placement in particular)

19. Why is indication so important? • It provides a paradigm for the picture we are reading. • More information will help tailor the report to your clinical question. • Depending on the indication, the hospital may not be reimbursed for the study

21. Contrast • Oral contrast is frequently used in CT of the abdomen and pelvis and is very safe • There are 2 types of intravenous contrast. • Iodinated contrast for CT • Gadolinium based contrast for MRI • Radiologists like contrast !! BUT Contrast is not without risks

22. Allergic Reactions to iodinated contrast • Can range from mild to severe (hives to anaphylaxis) • If mild allergic reaction, can pretreat with prednisone (50mg administered 13, 7, and 1 h prior to scan + Benadryl 1 hour before the scan) • If severe allergic reaction, contrast is contraindicated!

23. Iodinated contrast and renal failure • Contraindicated in renal failure (acute and chronic) because of risk of contrast induced nephropathy (CIN); Strict UNC cut off is Cr of 1.8. • Avoiding contrast in the setting of acute renal failure is important, but it is difficult for the radiologist, because the creatinine may be normal. (ie <1.8) • In hyper-acute renal failure, the creatinine hasn’t risen yet. Decreased urine output or anuria is acute renal failure – regardless of the creatinine. • Remember; first do no harm! Non-contrast studies can often be quite helpful.

24. MR Contrast and NSF • Risk of nephrogenic sclerosing fibrosis (NSF) increases with decreasing GFR; contraindicated <30 • Progressive fibrosis of skin in patients with renal failure (typically on dialysis) which result in painful contractures and, possibly, death. http://jama.ama-assn.org/content/vol297/issue3/images/medium/jmn60162fa.jpg

25. Reading an abdominal film

26. Where can you look at images • PACS workstations • ED • ICUs • WebCIS based PACS (java script) • Web Based PACS

27. Basics:Looking at Imaging Studies: • Adequate Study? • Correctly labeled with patient’s name, MR#, and the date of the study? • Technically adequate? • Systematic versus Focused look at a study: • Radiologist does both! • As the requesting clinician, you should also look at your patient’s study (at least plain films), as well as follow up on the final report. • PTX, PNA, pleural effusions, SBO, free air • Evaluate lines and tubes (especially the ones you placed!)

28. Several different type of abdominal film series • KUB (kidneys, ureter, bladder) • 2 View---AP supine and erect abdomen • Acute abdomen series: 2 view with upright chest • Lateral decubitus (Left or Right) • Cross table lateral---prone or supine

29. Systematic process • Lines and tube (enteric tube, feeding tube, foley catheter, rectal tube, fem lines) • Bowel gas pattern (dilated loops, air where it shouldn’t be) • Visceral contours (hepatomegaly, abnormal soft tissue mass) • Abnormal calcifications (gallstones, kidney stones) • Bones

30. Enteric tube (NG/OG) placement • Tip AND sidehole need to be within the stomach body for proper suction

31. REALLY BAD – enteric tube in lung http://icvts.ctsnetjournals.org/content/vol4/issue5/images/large/429fig1.jpeg

32. Small Bowel Obstruction (SBO) • Gasless abdomen if bowel loops are fluid filled • Dilated small bowel loops (>3cm) • Sometimes difficult to differentiate between SBO and ileus (both colon and small bowel tend to be dilated) http://archive.student.bmj.com/issues/02/04/education/102.php

33. Paucity of gas

34. CT correlate: SBO

35. Dilated loops of small bowel

36. CT correlate: more gas, & SBO

37. Pneumoperitoneum

38. Pneumoperitoneum

39. Abnormal calcifications: Gallstones supine and erect Air-fluid levels

40. CT correlate: Gallstones

41. Abnormal Calcifications: Nephrolithiasis

42. CT correlate: Nephrolithiasis

43. Abnormal calcifications: Appendocolith http://www.hawaii.edu/medicine/pediatrics/pemxray/v6c18.html

44. Plain film imaging of the Abdomen: Bones http://www.szote.u-szeged.hu/radio/trauma2/a2trau3a.htm

45. Radiology at UNC • The Department of Radiology at the University of North Carolina at Chapel Hill has eight clinical sections: • Abdominal Imaging (Body CT, US, MRI, Flouro studies such as UGI and SBFT, Biopsies) • Breast Imaging • Cardiopulmonary Imaging (Chest, Cardiac) • Musculoskeletal Imaging (Bone, ER RR, MSK MRI’s) • Neuroradiology (brain/spine CT & MRI; lumbar punctures) • Nuclear Medicine (wide variety, PET-CT, bone scans, Cards) • Pediatric Imaging (wide variety) • Vascular-Interventional (wide variety)

46. Calling Radiology • Try to call the right reading room (RR). • Each subspecialty has their own reading room • Calling the Neuro reading room to talk about a chest x ray will not get you far (like asking ENT to perform an appendectomy) • When paging, it’s nice to put your name/pager number immediately after the call back number • After hours: • 6-8850 Lower Level/ER RR • 216-2826 Upper Level (VIR, Doppler US, MRI) • DON’T call 6-8850 during the day • unless it’s an MSK radiology issue • When you call, identify yourself, and expect whoever answers to identify themselves. • Improves accountability • Always good policy to know who talked to

47. Please page us if our report is confusing!

48. Parting thoughts (for Radiology and beyond!) • Always try to be polite. This will be difficult when you are sleep deprived and overworked, but “please” and “thank you” go a long way in maintaining cordial relationships with your co-workers. • Try to resist the urge to “bad mouth” other specialties. • Speak up when you see something wrong!

49. RECAP • Radiology is a cool specialty. Think whether it’s a good fit as you go through the year. • CT is a great tool but provides a high does of radiation • Provide good indications! • IV Contrast + Sick Kidneys = BAD • If worried about free air in the abdomen, order upright or decubitus films

50. Hx: Please Evaluate New Line. “?!@#!%!” Thanks for listening! Questions?