Darius Biskup M.D.

1. What Imaging Study Should I Order for …?Approach to Imaging for Optimal Clinical Diagnosis: Musculoskeletal Disorders Darius Biskup M.D.

2. Disclosures • No financial disclosures

3. Objectives: • Review common musculoskeletal imaging modalities • Discuss advantages and disadvantages of imaging tests • Discuss use of contrast agents • Discuss imaging test approach to optimize clinical diagnosis of musculoskeletal disorders

4. Plain film Fluoroscopy CT MRI Nuclear Medicine Ultrasound Common Musculoskeletal Imaging Modalities

5. Advantages and Disadvantages • Knowing what a test can and can not assess will help optimize test ordering

6. Advantages Best initial test in most clinical settings Quick/available Excellent boney detail Broad assessment Can offer clues to narrow next diagnostic step Plain film

7. Disadvantages Poor assessment of soft tissues tendons, ligaments muscles organs Frequently negative for acute findings more likely positive in acute trauma Plain film

8. Advantages Offers dynamic assessment Needle guidance for arthrograms, joint injections, aspirations Fluoroscopy

9. Disadvantages Limited assessment of soft tissue Compliment with CT or MRI invasive – arthrogram, injection Fluoroscopy

10. Advantages Noninvasive, quick, convenient Excellent detail of osseous anatomy Surgical planning CT

11. Disadvantages Radiation Allergic reaction IV contrast Limitations in assessment of small soft tissue detail tendons, ligaments, effusions, bursitis CT

12. Advantages No radiation Excellent soft tissue detail Tendons, ligaments Cartilage Soft tissue, Muscles Marrow MRI

13. Disadvantages Pt claustrophobic sedation Limited assessment of osseous detail Weight limits Metal susceptibility artifact Motion sensitive Takes time Most scans 30 minutes MRI

14. Advantages No radiation Good targeted assessment Best initial test for vascular assessment DVT/ PVD Great test for pediatric patients Biopsy/aspiration guidance in soft tissues Ultrasound

15. Disadvantages Operator dependent Limited assessment Time dependant Ultrasound

16. Advantages Targeted exam Functional/metabolic exam Bone scan WBC Indium/gallium Nuclear Medicine

17. Disadvantages Targeted exam Limited spatial resolution May require additional imaging correlate abnormal activity on bone scan Nuclear Medicine

18. Renal function important! CT creatine < 1.5 MRI GFR > 45mL/min nephrogenic systemic fibrosis (NSF) No contrast for Dialysis If renal function is poor can always start with non-contrast study Allergic reactions Mild – hives pre-medicate Moderate bronchospasm, respiratory compromise consider another modality; do exam without contrast Severe- anaphylaxis – NO contrast IV contrast for CT or MRI

19. MRI/CT imaging of joints Most MSK studies for joint assessment do NOT need contrast Fractures – occult, nonunion Pre op planning IV contrast not needed

20. Any study assessing tumor/mass Allows better characterization Assess for “itis” Cellulitis/abscess osteomyelitis Post op lumbar spine MRA Lower extremity runoff - contrast When in doubt, let the radiologist figure it out Order MRI of … , contrast as needed. Consider authorization issues Talk to radiologist When to order IV contrast

21. Xray – most utilized modality and most commonly order in initial evaluation CT – multiplanar bony detail- complex fractures, osseous lesions MRI Tendons, ligaments, marrow edema contusions Internal derangement Nuclear medicine Bone scan Indium/sulfur colloid US Targeted assessment Choosing the right imaging test to optimize clinical diagnosis

22. Plain film • Excellent osseous detail • Key in initial evaluation of joints • Assess for fractures/dislocations • Arthritis • Osseous disorders/ mineralization • Hardware evaluation

23. CT • Excellent osseous detail • Good soft tissue detail • Useful for postoperative evaluation, complex fractures, occult fx, intra-articular loose bodies,fluid collections, soft tissue gas • Limited assessment of menisci, labra, ligaments, tendons, marrow assessment

24. MRI • Superior soft tissue detail • tendons, ligaments • Superior marrow evaluation • Edema, contusions, occult fx, osseous lesions • Limited osseous detail evaluation • Ferromagnetic susceptibility artifact • Motion • Claustrophobic pt – can sedate patients

25. Optimizing clinical diagnosis of MSK disorders with imaging

26. hx decreased ROM/ weakness/ impingement Plain film best initial test MRI to assess soft tissue Joint pain w/ negative findings/xray does not correlate

27. Tear vs Tendinosis

28. Full thickness tear

29. Partial articular surface tear

30. Patient has pacemaker – can we still evaluate rotator cuff? YES Arthrogram CT arthrogram adds anatomy Rotator cuff teas

31. Knee pain, negative xray Next step –MRI Menisci Ligaments Tendons

32. Is it useful? My patient has metal hardware, can I still order an MRI

33. How do I order it? eg – MRI right hip MARS protocol Assess soft tissue, effusions, fluid collections Tendons, ligaments Osteolysis adjacent to hardware Assessment of internal derangement if not joint replacement Metal Artifact Reduction Sequences (MARS)

34. Mass/lump felt by clinician or patient What to order first? Xray – best initial step Tumor/mass

35. Extremity soft tissue tumor/mass • Abnormal xray/ normal xray • If it can be normal, why order it? • Can aid in assessment of mass – calcifications, bone involvement • What to order next? • MRI • How to order it? • MRI w/ & w/o contrast tumor/mass protocol • e.g. MRI right lower extremity tumor/mass protocol w & w/o contrast

36. Capsule marker placed around mass If mass not initially found by patient, show exact location so the can reproduce site for exam Identifies target mass vs. additional not clinically detected lesions

38. Fall, back pain, age indeterminate compression fracture on xray

40. What if patient has pacemaker and there is a compression fracture deformity? • Bone scan

41. Back pain Xray initial best test Imaging of spine

42. CT spine– no IV contast Limited in assessment of spinal stenosis MRI spine w/o most routine work for LBP, radiculopathy MRI spine w/ & w/o Post op follow up Oncology Can’t do MRI, but I suspect central canal stenosis CT myelogram Imaging of spine

43. Low back pain, radiculopathy

44. Good option when can’t do MRI Pacemaker Post op metal Invasive Contrast injected into thecal sac CT myelogram

45. Nuclear Isotope Studies • Bone scan – infections, osteomyeltits, stress/insufficiency fx “ diffuse bone pain” • Limited spatial resolution – compliment with plain films • Indium/sulfur colloid – infections • esp with hardware • Gallium- infections

46. No hardware Plain film 3 phase bone scan Indium scan (gallium in spine) Hardware Plain film 3 phase bone Induim/sulfur colloid scan Marrow displacement I want to assess for osteomyeltis but my patient has a pacemaker

47. Plain film 3 phase bone scan Induim/sulfur colloid scan Marrow displacement I want to assess for hardware loosening vs infection

48. Objectives: • Review common musculoskeletal imaging modalities • Discuss advantages and disadvantages of imaging tests • Discuss use of contrast agents • Discuss imaging test approach to optimize clinical diagnosis of musculoskeletal disorders

49. Knowing what a test can and can not assess will help in optimal test ordering Xray most useful initial imaging modality MRI’s best done if targeted – soft tissue mass, joint, limb Protocols differ Many exams can be substituted to get a diagnosis if a condition prevents a desired exam Talk to your radiologist Take away pearls

50. Optimal for Mass/oncology “Itis” –infection, abscess Post op Lumbar spine Not needed MRI/CT of joints (not suspecting infection or mass) When in doubt, let the radiologist figure it out Talk to your radiologist Do I Need Contrast?