INFEROSUPERIOR AXIAL SHOULDER X-RAY

 

INFEROSUPERIOR AXIAL PROJECTION: SHOULDER

| WEST POINT METHOD

Stucture Shown:

• The resulting image shows bony abnormalities of the anterior inferior rim of the glenoid in patient with instability of the shoulder.

Technical Factor:

• IR size - 18 x 24 cm (8 x 10 inches), crosswise placed in contact with the superior surface of the shoulder
• 70 +- 5 kV range
• mAs 10

Shielding:

• Place lead shield over pelvis and radiosensitivity regions.

Inferosuperior axial shoulder joint: West Point method

Patient Position:

• Adjust the patient in the prone position with approximately a 3 inches ( 7.6 cm ) pad under the shoulder being examined.
• Turn the patient's head away from the side being examined.

Part Position:

• Abduct the arm of the affected side 90 degrees, and rotate so that the forearm rest over the edge of the table or a bucky tray, which may be used for support.
• Place a vertically supported IR against the superior aspect of the shoulder with the edge of the IR in contact with the neck.
• Support the IR with sandbags or a vertical IR holder

West Point method with anterior and medial central ray angulation

Central Ray:

• Directed at a dual of 25 degrees anteriorly from the horizontal and 25 degrees medially.
• The CR enters approximately 5 inches (13 cm) inferior and 1 1/2 inch (3.8 cm) medial to the acromial edge and exits the glenoid cavity.

Collimation:

• Collimate closely on four sides.

Respiration:

• Suspend respiration during exposure.

RADIOGRAPHIC CRITERIA ON WEST POINT METHOD

Structure Shown:

• Humeral head projected free of the coracoid process
• Articular between the head of the humerus and the glenoid cavity
• Acromion superimposed over the posterior portion of the humeral head
• Shoulder joint

• Collimation should be visible on four sides to the affected shoulder.

Exposure Criteria:

• Optimal density and contrast with no motion will demonstrate clear, sharp bony trabecualr markings.
• The bony margins of the acromion and coracoid process will be visible through the humeral head.