Glenohumeral joint: comparison of shoulder positions at MR arthrography.
OBJECTIVE
To compare neutral, external rotation, and abduction external rotation positions of the glenohumeral joint during magnetic resonance (MR) arthrography in the assessment of the joint capsule, biceps-labral complex, and glenohumeral ligaments.


METHODS
MR imaging with intraarticular administration of gadopentetate dimeglumine was performed in 10 adult cadaveric glenohumeral joints. Fat-suppressed oblique coronal, oblique sagittal, and axial. T1-weighted spin-echo imaging and axial three-dimensional spoiled gradient-recalled imaging were 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 findings were correlated.


RESULTS
The biceps-labral complex was best visualized 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.


CONCLUSIONS
Although MR arthrography of the glenohumeral joint clearly delineates the biceps-labral complex and glenohumeral ligaments, external rotation of the shoulder optimizes visualization of the former structures. Abduction external rotation is the best position for evaluation of the inferior glenohumeral ligament and anterior capsular attachment.
Department of Radiology, Veterans Administration Medical Center, San Diego, USA.
S M
SM
Kwak
R R
RR
Brown
D
D
Trudell
D
D
Resnick
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001175:Arthrography; D005260:Female; D006801:Humans; D007089:Image Enhancement; D007091:Image Processing, Computer-Assisted; D008023:Ligaments, Articular / Q000033:anatomy & histology; D008279:Magnetic Resonance Imaging; D008297:Male; D016059:Range of Motion, Articular / Q000502:physiology*; D012016:Reference Values; D012785:Shoulder Joint / Q000473:pathology*