Figure 2a. Normal anatomy as depicted on coronal oblique T1-weighted magnetic resonance (MR) arthrographic images (repetition time msec/echo time msec = 700/10) obtained with fat saturation after intraarticular administration of dilute gadolinium compound. (a) Rotator interval is anatomically defined by superior border of subscapularis tendon (*) and anterior border of supraspinatus tendon. Also shown is distal portion of normal coracohumeral-superior glenohumeral ligamentous anchor (arrow) at site of insertion on the lesser tuberosity medial to and intimately associated with the long head of the biceps brachii tendon (arrowhead in a and b). Long head of the biceps brachii tendon slips over the coracohumeral-superior glenohumeral ligamentous anchor to insert on the superior labrum, as shown on (b) subsequent image. The "pulley" effect of this ligamentous anchor can be inferred from a.