| Radiographs |
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- Shoulder trauma series includes at least:
- “true” anteroposterior view
- axillary lateral view
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| Computed Tomography |
- Overview
- provides better detail of cortical and trabecular bone structures than MRI at cost of higher radiation exposure
- there for optimal for visualization of bony defects
- magnification artifacts that are associated with radiographs do not occur with CT
- Axial Shoulder Images
- useful to visulaize
- Reverse Hill Sachs
- Coronal Shoulder Images
- Sagittal Shoulder Images
- useful to visualize
- anterior-inferior glenoid insufficiency
- 3D Reconstructions
- useful to visualize
- glenoid version for total shoulder arthroplasty
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| Magnetic Resonance Imaging |
- Overview
- MRI is best for evaluating soft tissue structures and evaluating bone contusions or trabelcular microfractures
- the stronger the magnet, the higher the intrinsic signal-to-noise ratio (e.g. a 3 Tesla MRI machine has 9x the proton energy of a 1.5 Tesla MRI machine)
- T1-weighted sequence
- uses a short repetition time (TR) and short echo time(TE)
- bright= fat
- dark= fluid, bone, ligament, bone marrow, and fibrocartilage
- often combined with MR arthrograms
- useful to visualize
- T2-weighted sequence
- uses a long TR and long TE
- bright= fluid (inflammation) and bone marrow
- dark= bone, ligament, muscle, and fibrocartilage
- useful to visualize
- rotator cuff pathology
- full thickness tear
- Short tau inversion recovery (STIR)
- Fat saturation (e.g. suppression) technique
- technique that reduces signal from fat and increases signal from fluid and edema
- helps to determe edema versus fatty infiltration in the rotator cuff muscles
- useful to visualize
- ABER (abduction external rotation) position
- sequence beyond the conventional 3 sequences (coronal, sagittal, and axial)
- patient places affected hand behind their head instead of a true 90-90 degree abduction-external rotation position
- position tensions the anteroinferior glenohumeral ligament and labrum and relaxes the capsule
- useful to visualize
- Bankart lesions
- partial- and full-thickness tears of the rotator cuff tendons
- internal impingement
- MR arthrogram
- commonly used to augment MRI to diagnose soft-tissue problems such as SLAP tears
- dilute gadolinium-containing solution is percutaneously injected into the joint.
- optimal for
- labral and ligament pathology
- Bankart lesion
- Superior labrum anterior-posterior tear (SLAP)
- Glenoid labral articular disruption (GLAD)
- Anterior labral periosteal sleeve avulsion (ALPSA)
- Humeral avulsion of the glenohumeral ligament (HAGL)
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