Efficacy of ultrasonography-guided shoulder MR arthrography using a posterior approach

Shoulder MR arthrography has an important role in the assessment of rotator cuff lesions, labral tears, glenohumeral ligaments, rotator interval lesions, and postoperative shoulder status. Injection in direct MR arthrography can be performed with palpation, fluoroscopy, ultrasonography (US), or MRI. Recently, the posterior approach is the preferred method due to the presence of fewer stabilizers, absence of important articular structures and less extravasation, has been advocated. Our aim was to assess the efficacy of US-guided MR arthrography via a posterior approach on the glenohumeral joint. Thirty MR arthrographies were performed on 29 patients. Ultrasonography (Xario, Toshiba) examinations were conducted by a wide-band 5-12 Mhz linear array transducer set to muscle-skeleton. Diluted contrast medium (1 ml gadolinium chelate and 100 ml saline, approximately 15 ml) was delivered into the glenohumeral joint space from between the humeral head and posterior labrum with a 20-gauge spinal needle. MRI examination was conducted by a 1.5 T scanner. Fat-saturated T1-weighted spin echo was applied on coronal, axial, and sagittal planes within the first 30 min after contrast material injection. One (3.3%) arthrography was not successful due to technical reasons associated with obesity. Contrast extravasation around the infraspinatus and teres minor muscles was depicted in twelve examinations. One (3.3%) patient developed vasovagal collapse. Ultrasonography-guided posterior approach is an easy, reliable, fast, and comfortable method in experienced hands. It may be an alternative for fluoroscopy-guided shoulder MR arthrography.