What kind of MRI is recommended for evaluating scapulothoracic dyskinesis?

MRI Protocol for Scapulothoracic Dyskinesis

For scapulothoracic dyskinesis, the recommended MRI protocol should include high-resolution T1-weighted and T2-weighted sequences with fat suppression in both neutral and arms-abducted positions to evaluate the scapulothoracic interface and identify inflammation or structural abnormalities. 1

Optimal MRI Protocol Components

Essential Sequences

• High-resolution T1-weighted sequences in sagittal and axial planes
• T2-weighted sequences with fat suppression (STIR or fat-saturated T2)
• Images should be obtained in both:
  • Neutral position
  • Arms-abducted position (provocative position)

Technical Considerations

• Imaging should cover the entire scapula and surrounding soft tissues
• Fluid-sensitive sequences are critical for identifying inflammation 2
• Sagittal imaging plane is particularly important for evaluating the scapulothoracic interface
• Axial imaging helps assess muscular attachments and potential sites of compression

Clinical Rationale

Scapulothoracic dyskinesis involves abnormal positioning and motion of the scapula that can lead to pain and functional limitations 3. MRI evaluation is beneficial because:

1. It can identify inflammation adjacent to bony deformities that may be causing symptoms 2
2. It allows evaluation of the periscapular muscles (particularly serratus anterior, trapezius, and rhomboids) that control scapular movement
3. It can detect structural abnormalities that may contribute to dyskinesis, such as:
   • Bony variations or prominences
   • Bursitis
   • Soft tissue lesions
   • Muscular pathology including fibrosis or denervation

Diagnostic Approach

The American College of Radiology guidelines for thoracic outlet syndrome recommend MRI with the following approach 1:

• Evaluate anatomic spaces in both neutral and arms-abducted positions
• Use sagittal T1-weighted imaging to demonstrate effacement of fat adjacent to the brachial plexus
• Include turbo spin-echo T2-weighted or STIR sequences to identify inflammation

When to Consider Contrast

Intravenous contrast (gadolinium) is generally not required for the initial evaluation of scapulothoracic dyskinesis unless there is concern for:

• Inflammatory conditions
• Neoplastic processes
• Infection
• Vascular abnormalities

Common Pitfalls to Avoid

1. Failure to image in both neutral and provocative positions, which may miss dynamic compression
2. Inadequate coverage of the entire scapula and surrounding soft tissues
3. Omitting fluid-sensitive sequences, which are crucial for identifying inflammation
4. Relying solely on imaging findings without clinical correlation, as anatomical variations may be present in asymptomatic individuals

Additional Considerations

In some cases, complementary imaging may be beneficial:

• Plain radiographs to identify bony abnormalities or cervical ribs
• CT for detailed evaluation of bony structures when MRI findings are equivocal
• Dynamic ultrasound can be useful for real-time evaluation of scapular motion but has limitations in visualizing deeper structures

By following this protocol, clinicians can accurately identify the underlying causes of scapulothoracic dyskinesis and develop appropriate treatment strategies to improve patient outcomes.