PA Oblique Projection - Lateral Rotation Wrist Xray Positioning

Lateral Rotation

Image Receptor: 8 x 10 inches, lengthwise or crosswise for 2 images on one IR.

Patient Position:

Let patient seat at the end of the radiographic table, placing the axilla in contact with the table.

Part Position

• Rest the palmar surface of the wrist on the IR.
• Adjust the IR so that its center point is under the scaphoid when the wrist is rotated from the pronated position.
• From the pronated position, rotate the wrist laterally or externally until it forms an angle of approximately 45 degrees with the plane of the image reception. For exact positioning and to ensure duplication in follow-up examinations, place a 45 degrees foam wedge under the elevated side of the wrist.
• Extend the wrist slightly, and if the digits do not touch the table, support them in place.
• When the scaphoid is under examination, adjust the wrist in ulnar deviation. Place a sandbag across the forearm.
• Shield gonads.

Central ray:

Central ray is perpendicular to the midcarpal area. It enters just distal to the radius.

Structure shown:

This projection demonstrates the carpals on the lateral side to the wrist, particularly the trapezium and the scaphoid. The scaphoid is superimposed on itself in the direct PA projection.

Evaluation Criteria:

• The following should be clearly demonstrated:
• A well demonstrated scaphoid and trapezium. 
• Distal radius and ulna, carpals and proximally half of metacarpals.
• Soft tissue and bony trabeculation

Usually, adequate amount of obliquity in the following circumstances.

1. Slight interosseous space between the 3rd to 4th metacarpal shafts
2. Slight overlap of the distal radius and ulna