Musculoskeletal Ultrasound Fundamentals

Benjamin D. Levine, M.D.Associate Professor of Radiology

Musculoskeletal Imaging

Dept. of Radiological Sciences

UCLA Health System

Musculoskeletal UltrasoundI. 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

Image Optimization

Musculoskeletal UltrasoundImage Optimization

Equipment:

• High frequency (> 10 MHz) linear transducers

• Knobology Depth

Focal zone

Gain

Doppler

Extended Field of View

Cine

Image Interpretation

Artifacts

Musculoskeletal UltrasoundImage Interpretation

Artifacts

• Anisotropy

• 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; 26:589-604

Musculoskeletal UltrasoundImage Interpretation

Artifacts

• Anisotropy

Applications

Musculoskeletal UltrasoundApplications

• Ideal alternative or complement to MRI for imaging superficial structures

• MRI standard of care for• Ligament (most)

• Cartilage

• Intraosseous/marrow abnormalities

Musculoskeletal UltrasoundForeign Bodies

• FB as small as 0.5 mm

• Non radioopaque wood and plastic

• Identifies FB and complications

• Can mark skin for surgical removal

Musculoskeletal UltrasoundPeripheral Nerves

• Hypoechoic individual nerve fascicles

• Honeycomb in short axis

Musculoskeletal UltrasoundDynamic Imaging

Specific maneuver needed to elicit the pathology

• Tendon or nerve subluxation/dislocation

• Snapping syndromes

• Muscle hernia

• Impingement syndromes

• Partial vs. complete tears

Musculoskeletal UltrasoundImaging around Hardware

• Reverberation artifact is deep to metal

• Can image overlying tendons/ligaments

• Dynamic imaging of soft tissues over hardware

• Ultrasound guided aspiration

Musculoskeletal UltrasoundGuided Procedures

Iliopsoas bursal/peritendinousinjection

• 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

Musculoskeletal UltrasoundFocal Tendon Abnormality

Tenosynovitis

Musculoskeletal UltrasoundFocal Tendon Abnormality

Tendinopathy

• Loss of fibrillar echotexture

• Heterogeneous

• Thickened

• Hypoechoic

• Smooth subcortical bone

Musculoskeletal UltrasoundFocal Tendon Abnormality

Tear• Non visualization

• Focal hypoechoic tendon defect

• Flattening of bursal surface

• Secondary Signs Cortical irregularity

Bursal fluid

Joint effusion

Musculoskeletal UltrasoundFocal Tendon Abnormality

Partial Thickness Tear

• Articular

• Intrasubstance

• Bursal

Musculoskeletal UltrasoundFocal Tendon Abnormality

Full Thickness Tear

• Articular/intrasubstance/bursal

• Loss of superior convexity

• Retraction

Musculoskeletal UltrasoundEvaluation 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

Musculoskeletal UltrasoundI. 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

Musculoskeletal Ultrasound Fundamentals

Benjamin D. Levine, M.D.Associate Professor of Radiology

Musculoskeletal Imaging

Dept. of Radiological Sciences

UCLA Health System