Glenohumeral joint instability is extremely common. With regard to primary anterior shoulder dislocations, the incidence is between 8.2 and 23.9 per 100 000 person-years, with an estimated prevalence of 1.7%. Many imaging methods, including arthrography, CT arthrography, MR arthrography, have been used to image the glenoid labrum and the associated structures of the capsular mechanism. The aim of the study is to prove MR arthrography is the preferred imaging technique for the investigation of patients with shoulder instability. MR arthrography reliably shows subtle lesions of the labroligamentous complex, providing information essential to the surgeon concerning the surgery or arthroscopic repair .Thirty Patients with clinically evident or suspected shoulder impingemint or glenohumeral instability.of both sexes were included , conventional MRI was performed for all patients followed by CT guided intraarticular contrast injection then MRI Arthrography images taken within thirty minutes. Data were collected, revised, coded and entered to the Statistical Package for Social Science (IBM SPSS) version 20.