CT is Not Effective for Evaluating Shoulder Rotator Cuff Injuries
CT is virtually ineffective for diagnosing rotator cuff tears and should not be used as the primary imaging modality for evaluating rotator cuff injuries. 1
Limitations of CT for Rotator Cuff Evaluation
- CT has virtually no usefulness in diagnosing common traumatic soft-tissue injuries such as rotator cuff tears, labroligamentous injuries, and muscle tears 1
- Noncontrast CT is unable to assess rotator cuff pathology in the acute setting 1
- CT is considered inferior to MRI for diagnosing essentially all soft-tissue shoulder injuries 1
Recommended Imaging Modalities for Rotator Cuff Evaluation
Initial Assessment
- Plain radiographs should be the initial imaging modality to rule out fractures, dislocations, and other bony abnormalities 2
- Standard radiographs should include anteroposterior (AP) views in internal and external rotation, plus an axillary or scapula-Y view 1, 3
Preferred Imaging Modalities
- MRI without contrast is the best overall modality for assessing rotator cuff pathology with high sensitivity and specificity for full-thickness tears 2, 1
- Ultrasound is equivalent to MRI for evaluating full-thickness rotator cuff tears with a sensitivity of 85% and specificity of 90% 2, 1
- MR arthrography is superior to noncontrast MRI for diagnosing partial-thickness rotator cuff tears and intra-articular pathology 1, 2
When CT Might Be Appropriate
- CT arthrography can be considered as an alternative when MRI is contraindicated 1
- CT arthrography has similar performance to MR arthrography for detecting full-thickness rotator cuff tears, but significantly poorer performance for partial-thickness tears 1, 2
- CT is the gold standard for diagnosing and characterizing fractures, which may be associated with rotator cuff injuries 1
Comparative Performance of Imaging Modalities
- MRI and ultrasound both demonstrate high accuracy for full-thickness tears but more variable results for partial-thickness tears 4, 5
- MR arthrography is considered the gold standard for imaging traumatic shoulder pain 1
- Ultrasound is operator-dependent but offers advantages of being dynamic, non-invasive, and lower cost 6, 2
- FDG-PET/CT and bone scans are not routinely used for diagnosing rotator cuff tears 2
Clinical Implications
- Accurate diagnosis of rotator cuff tears is essential for guiding appropriate treatment and achieving favorable clinical outcomes 5
- Complete tears are the main decision point for pursuing surgical repair, making accurate detection particularly important 1
- In older patients with shoulder dislocation, associated rotator cuff tears are common and should not be overlooked 3
In conclusion, while CT is excellent for evaluating bony structures and fractures, it should not be used as the primary imaging modality for evaluating rotator cuff injuries. MRI, ultrasound, or MR arthrography are the appropriate first-line imaging studies after radiographs when rotator cuff pathology is suspected.