Kinematic MRI of the shoulder

Area of Science:

• Radiology
• Orthopedic Imaging
• Musculoskeletal Imaging

Background:

• Shoulder pain evaluation is challenging due to its dynamic and positional nature.
• Soft tissue deformation during motion complicates static imaging of the glenoid humeral joint.

Purpose of the Study:

• To assess the utility of dynamic cyclic cine imaging for evaluating the glenoid humeral joint.
• To improve the accurate diagnosis of shoulder pathologies through motion-based imaging.

Main Methods:

• Kinematic MRI with a dedicated shoulder coil was performed.
• The Bonutti cine shoulder system facilitated incremental rotational movement (10-degree intervals).
• Images were reformatted into dynamic cine loops from internal to external rotation.

Main Results:

• Dynamic cine imaging readily identified normal glenoid labrum variations and capsular attachments.
• Labral signal and morphology varied significantly with rotation, deeming static assessment unreliable.
• Subcoracoid impingement was identified by a <11 mm subcoracoid space narrowing in internal rotation.

Conclusions:

• Dynamic cine MRI is essential for accurate diagnosis of the capsular/labral complex.
• Static MRI is insufficient for assessing morphologic changes that vary with extremity position.
• Cine studies accurately and reproducibly identify capsular attachments and subcoracoid impingement.