Musculoskeletal Ultrasound Fundamentals

Transcription

1 Fundamentals Benjamin D. Levine, M.D. Associate Professor of Radiology Musculoskeletal Imaging Dept. of Radiological Sciences UCLA Health System

2 I. Image Optimization II. Image Interpretation Artifacts III. Applications Soft Tissue Foreign bodies Peripheral nerves Dynamic imaging Imaging around hardware Guided procedures Focal tendon abnormality Evaluation of cyst/fluid collection

3 Image Optimization

4 Equipment: Musculoskeletal Ultrasound Image Optimization High frequency (> 10 MHz) linear transducers Knobology Depth Focal zone Gain Doppler Extended Field of View Cine

5 Image Interpretation Artifacts

6 Artifacts Anisotropy Musculoskeletal Ultrasound Image Interpretation Variation of ultrasound interaction with fibrillar tissue Sound beam not perpendicular to long axis of a structure Small degrees (5 ) of beam angulation can result in anisotropy Tendons and ligaments Rutten JC, et al. Radiographics 2006; 26:

7 Artifacts Musculoskeletal Ultrasound Image Interpretation Anisotropy

8 Applications

9 Applications Ideal alternative or complement to MRI for imaging superficial structures MRI standard of care for Ligament (most) Cartilage Intraosseous/marrow abnormalities

10 Foreign Bodies FB as small as 0.5 mm Non radioopaque wood and plastic Identifies FB and complications Can mark skin for surgical removal

11 Peripheral Nerves Hypoechoic individual nerve fascicles Honeycomb in short axis

12 Dynamic Imaging Specific maneuver needed to elicit the pathology Tendon or nerve subluxation/dislocation Snapping syndromes Muscle hernia Impingement syndromes Partial vs. complete tears

13 Imaging around Hardware Reverberation artifact is deep to metal Can image overlying tendons/ligaments Dynamic imaging of soft tissues over hardware Ultrasound guided aspiration

14 Guided Procedures Iliopsoas bursal/peritendinous injection Safe and effective Useful in excluding the tendon as the cause of pain Guides surgical decision making (tendon release) Adler RS, et al. AJR 2005; 185:940-43

15 Focal Tendon Abnormality Tenosynovitis

16 Focal Tendon Abnormality Tendinopathy Loss of fibrillar echotexture Heterogeneous Thickened Hypoechoic Smooth subcortical bone

17 Tear Musculoskeletal Ultrasound Focal Tendon Abnormality Non visualization Focal hypoechoic tendon defect Flattening of bursal surface Secondary Signs Cortical irregularity Bursal fluid Joint effusion

18 Focal Tendon Abnormality Partial Thickness Tear Articular Intrasubstance Bursal

19 Focal Tendon Abnormality Full Thickness Tear Articular/intrasubstance/bu rsal Loss of superior convexity Retraction

20 Evaluation of a Benign Cyst/Fluid Collection Popliteal (Baker s) cyst Communication to joint between medial gastroc and semimembranosus tendons Leaking/rupture can present as complex mass in calf

21 I. Image Optimization II. Image Interpretation Artifacts III. Applications Soft Tissue Foreign bodies Peripheral nerves Dynamic imaging Imaging around hardware Guided procedures Focal tendon abnormality Evaluation of cyst/fluid collection

22 Fundamentals Benjamin D. Levine, M.D. Associate Professor of Radiology Musculoskeletal Imaging Dept. of Radiological Sciences UCLA Health System