Yes, CT arthrography is an excellent alternative when MRI cannot be performed for shoulder injury evaluation.
If MRI is contraindicated or unavailable, CT arthrography of the shoulder is a highly accurate diagnostic option that provides comparable sensitivity and possibly improved specificity for detecting labral lesions and can better visualize osseous abnormalities. 1
When CT Arthrography is Particularly Useful
CT arthrography excels in several specific scenarios:
- Absolute MRI contraindications: Patients with pacemakers, defibrillators, or other implanted electronic devices 2
- Metallic hardware: Patients with surgical metal implants near the shoulder that create MRI artifacts 2
- Claustrophobia: Patients unable to tolerate MRI 2
- Post-surgical shoulders: CT arthrography demonstrates 94% accuracy in operated shoulders compared to only 25% with MRI 2
Diagnostic Performance
The evidence demonstrates strong diagnostic accuracy for CT arthrography:
- Labral lesions: Sensitivity of 85-88% for detecting Bankart and SLAP lesions, with comparable performance to MR arthrography 3, 4
- Full-thickness rotator cuff tears: Sensitivity of 73% 4
- Bony abnormalities: Superior visualization of glenoid rim fractures, Hill-Sachs lesions, and other osseous pathology 1, 3
- Overall accuracy: 96% accuracy when compared to arthroscopic findings 5
Important Limitations to Consider
CT arthrography has specific weaknesses you should recognize:
- Partial-thickness rotator cuff tears: Significantly inferior to MRI for detecting these lesions 3
- Soft tissue detail: Cannot assess rotator cuff and labroligamentous pathology as comprehensively as MRI 1
- Capsular lesions: Lower sensitivity (44%) compared to CT arthrography's 96% for capsular pathology 5
- Radiation exposure: Involves ionizing radiation, unlike MRI
Clinical Algorithm
When MRI is not possible, proceed as follows:
- For instability/labral concerns: CT arthrography is an excellent choice with comparable diagnostic accuracy to MR arthrography 1, 3
- For bone loss assessment: CT arthrography provides superior visualization of glenoid and humeral head osseous defects 1
- For rotator cuff evaluation: Consider that full-thickness tears are well-detected, but partial tears may be missed 3, 4
- Post-operative evaluation: CT arthrography is significantly superior to MRI in this setting 2
Common Pitfall
The most recent ACR guidelines 1 note that while CT arthrography provides excellent labral visualization, there is interobserver variability in reporting labral lesions. Ensure your radiologist has musculoskeletal expertise for optimal interpretation 2.