Usefulness of intravenous contrast-enhanced MRI for diagnosis of adhesive capsulitis.

OBJECTIVES

We aimed to compare the reliability and performance of MRI measures enhanced with intravenous (IV) injection of gadolinium contrast versus non-enhanced MRI measures for the diagnosis of adhesive capsulitis (AC). We also aimed to examine the association between MRI findings and clinical features in patients with AC.

METHODS

MRI of 42 patients with a clinical diagnosis of AC confirmed by arthrography and that of 42 patients in a control group were retrospectively studied by 2 blinded readers. Reliability and performance of MRI findings were compared between IV contrast-enhanced measures and non-enhanced MRI measures in T2-weighted fat-saturated and T1-weighted images. MRI findings were correlated with clinical stage, etiology, and pain.

RESULTS

Sensitivity (97.6%) and specificity (97.6%) of axillary-recess capsule signal enhancement for AC diagnosis were significantly superior (p = 0.02) to hyperintense signals on T2-weighted fat-suppressed images (sensitivity 90.5%, specificity 92.7%). Measures of the intensity signal in the area of the rotator interval were less performant for AC diagnosis but could be improved with joint capsule enhancement. Moreover, we found very high specificity (100%) of enhancement of the coracohumeral ligament signal for AC diagnosis. The early stage of adhesive capsulitis was positively correlated with joint capsule enhancement in the rotator interval. Secondary etiology of capsulitis was correlated with joint capsule hyperintensity signals of the rotator interval on T2-weighted fat-suppressed images.

CONCLUSION

IV contrast injection with MRI can be helpful for AC diagnosis in difficult cases. The stage of AC seems related to joint capsule enhancement in the rotator interval.

KEY POINTS

• IV gadolinium-enhanced MRI can improve the analysis of signal changes in the shoulder synovium and capsule of the shoulder that are related to adhesive capsulitis. • As an original finding, we observed that coracohumeral ligament enhancement had a 100% specificity for the diagnosis of adhesive capsulitis. • The intensity of enhanced signals in the rotator interval seems to be related to the early stage of frozen shoulder.