GLENOHUMERAL JOINT - COMPARISON OF SHOULDER POSITIONS AT MR ARTHROGRAPHY

PURPOSE: To compare neutral, external rotation, and abduction external rotation positions of the glenohumeral joint during magnetic resonanc e (MR) arthrography in the assessment of the joint capsule, biceps-lab ral complex, and glenohumeral ligaments. MATERIAL AND METHODS: MR imag ing with intraarticular administration of gadopentetate dimeglumine wa s performed in 10 adult cadaveric glenohumeral joints. Fat-suppressed oblique coronal, oblique sagittal, and axial T1-weighted spin-echo ima ging and axial three-dimensional spoiled gradient-recalled imaging wer e performed with each shoulder in the neutral, external rotation, and abduction external rotation positions. Shoulders were sectioned in the planes that yielded optimal MR images Anatomic and MR imaging finding s were correlated. RESULTS: The biceps-labral complex was best visuali zed on oblique coronal and axial images obtained in external rotation. Oblique axial abduction external rotation imaging best delineated the inferior glenohumeral ligament but did not improve assessment of the superior and middle glenohumeral ligaments in comparison with findings in neutral and external rotation. CONCLUSION: Although MR arthrograph y of the glenohumeral joint clearly delineates the biceps-labral compl ex and glenohumeral ligaments, external rotation of the shoulder optim izes visualization of the former structures. Abduction external rotati on is the best position for evaluation of the inferior glenohumeral li gament and anterior capsular attachment.