MR arthrography has specifically outperformed noncontrast MRI in assessment of glenohumeral ligament and anterior labral injuries [17,19], which are commonly seen in shoulder instability. MR arthrography has also outperformed noncontrast MRI in diagnosis of rotator cuff tears [17,19], which is a common associated finding in older patients with shoulder dislocation. However, high sensitivities reported for MR arthrography in the detection of labral pathology may not be applicable to patients with clinically unstable shoulders. A retrospective review of 90 patients with clinically unstable shoulders selected for arthroscopy [60] found that MR arthrography had a sensitivity of 65% for detection of labral tears. The authors proposed that this discrepancy with prior studies was the result of different patient selection criteria (clinically unstable in their study versus less-specific symptoms such as shoulder pain in others) and the interpretation of MR arthrography by experienced musculoskeletal radiologists [60]. For this document, it is assumed the procedure is performed and interpreted by an expert. MRI Shoulder MRI without contrast may be preferred to MR arthrography in the setting of acute shoulder dislocation when a post-traumatic joint effusion is present to provide sufficient visualization of soft-tissue structures. In the subacute or chronic setting, the glenohumeral joint effusion is usually too small to provide adequate joint distention for optimal assessment of soft-tissue structures. Noncontrast MRI has been shown to be inferior to MR arthrography in diagnosing labroligamentous and rotator cuff injuries [17,19]. Noncontrast MRI performs comparably to CT in evaluating glenoid and humeral head bone loss [12,18], which may obviate the need for noncontrast CT. CT Arthrography Shoulder CT Arthrography Shoulder CT arthrography is effective in evaluation of shoulder instability.
Shoulder Pain Traumatic PCAs. MR arthrography has specifically outperformed noncontrast MRI in assessment of glenohumeral ligament and anterior labral injuries [17,19], which are commonly seen in shoulder instability. MR arthrography has also outperformed noncontrast MRI in diagnosis of rotator cuff tears [17,19], which is a common associated finding in older patients with shoulder dislocation. However, high sensitivities reported for MR arthrography in the detection of labral pathology may not be applicable to patients with clinically unstable shoulders. A retrospective review of 90 patients with clinically unstable shoulders selected for arthroscopy [60] found that MR arthrography had a sensitivity of 65% for detection of labral tears. The authors proposed that this discrepancy with prior studies was the result of different patient selection criteria (clinically unstable in their study versus less-specific symptoms such as shoulder pain in others) and the interpretation of MR arthrography by experienced musculoskeletal radiologists [60]. For this document, it is assumed the procedure is performed and interpreted by an expert. MRI Shoulder MRI without contrast may be preferred to MR arthrography in the setting of acute shoulder dislocation when a post-traumatic joint effusion is present to provide sufficient visualization of soft-tissue structures. In the subacute or chronic setting, the glenohumeral joint effusion is usually too small to provide adequate joint distention for optimal assessment of soft-tissue structures. Noncontrast MRI has been shown to be inferior to MR arthrography in diagnosing labroligamentous and rotator cuff injuries [17,19]. Noncontrast MRI performs comparably to CT in evaluating glenoid and humeral head bone loss [12,18], which may obviate the need for noncontrast CT. CT Arthrography Shoulder CT Arthrography Shoulder CT arthrography is effective in evaluation of shoulder instability.