POSTERIOR OBLIQUE POSITION—GLENOID CAVITY: SHOULDER (NONTRAUMA)

 Pathology demonstrated :

 Fractures or dislocations of proximal humerus

• Fractures of glenoid labrum or brim

• Bankart lesion, erosion of glenoid rim, the integrity of the scapulohumeral joint, and other degenerative conditions.

IR size :

18 × 24 cm (8 × 10 inches).

IR POSITION :

crosswise / inpucky.

Shielding :

 Shield radiosensitive tissues outside region of interest.

Patient position :

Perform radiograph with patient in an erect or supine position. (The erect position is usually less painful for patient, if condition allows.)

Part position :

• Rotate body 35° to 45° toward affected side (see Note). If the radiograph is performed with the patient in the supine position, place supports under elevated shoulder and hip to maintain this position.

• Center midscapulohumeral joint to CR and to center of IR.

• Adjust cassette so that top of IR is about 2 inches (5 cm) above shoulder and side of IR is about 2 inches (5 cm) from lateral border of humerus.

• Abduct arm slightly with arm in neutral rotation.

CR :

CR perpendicular to IR, centered to scapulohumeral joint, which is approximately 2 inches (5 cm) inferior and medial from the superolateral border of shoulder.

Collimation :

Collimate so that upper and lateral 

borders of the field are to the soft tissue margins.

criteria :

Anatomy Demonstrated: 

• Glenoid cavity should be seen in 

profile without superimposition of humeral head.

Position: 

• Scapulohumeral joint space should be open.

• Anterior and posterior rims of glenoid cavity are superimposed.

• Collimation to area of interest.

Exposure: 

• Optimal density (brightness) and contrast with no motion visualize soft tissue margins and clear, sharp bony trabecular markings. 

• Soft tissue detail of the joint space and axilla should be visualized.