Conventional direct arthrography is usually performed prior to MR or CT exam in order to better depict subtle changes of cartilage and periarticular soft tissues. However, in the case of gross pathology, it could be used for making a definite diagnosis. 

Since subacromial-subdeltoid bursa does not normally communicate with the joint space, its depiction during arthrography is pathognomonic of full-thickness tear of a rotator cuff tendon.