Extra-articular contrast material leaks into locations unrelated to the injection path in shoulder MR arthrography

To evaluate the localisation, frequency and amount of extravasation in patients with extra-articular contrast material leak into locations unrelated to the injection path in shoulder magnetic resonance (MR) arthrography and associated shoulder disorders.

The sites of extravasation were determined on the shoulder MR arthrography of 40 patients. The extravasations were measured on three vertical planes of the MR arthrography. Sufficient joint distension was assessed according to the transverse diameters of the axillary recess on coronal MR images.

Extravasation of the contrast material occurred through the subscapular recess, the synovium of the biceps, and the axillary recess. In four cases, extravasations were observed in more than one anatomic location. The most common site of extravasation was along the subscapularis muscle. Superior labrum anterior-posterior (SLAP) lesions were found to be most frequently associated with extravasations. The amount of extravasation was significantly higher in patients with adhesive capsulitis compared with the patients with a different diagnosis (p = 0.022).

The extravasations adjacent to the axillary recess do not always indicate glenohumeral ligament pathology. Massive subscapular extravasations were most frequently associated with adhesive capsulitis and SLAP lesions, and might be considered in the MR arthrography report.

• Contrast material extravasation may reduce the diagnostic value of shoulder MR arthrography. • The extravasations may occur into locations unrelated to the injection path. • The extravasations adjacent to axillary recess can be misleading for HAGL lesion. • Massive subscapular extravasations were frequently associated with adhesive capsulitis and SLAP lesions.