(Wrist) PA Projection (Ulnar deviation)
Central ray
* Perpendicular to the scaphoid * Central ray angulation of 10 to 15 degrees proximally or distally sometimes required for clear delineation
Evaluation Criteria: The following should be clearly shown:
*Evidence of proper collimation *Distal radius of ulna, carpals, and proximal half of metacarpals *Scaphoid with adjacent articulations open *No rotation of wrist *Maximum ulnar deviation, as revealed by the angle formed between the longitudinal axis of the ulna and the longitudinal axis of the fifth metacarpal *soft tissue and bony trabecular detail
Position of part
*position the wrist on the IR for a PA projection *Without moving the forearm, turn the hand outward until the wrist is in extreme ulnar deviation * shield gonads
Collimation
2.5 inches (6 cm) proximal and distal to the wrist joint and 1 inch (2.5 cm) on the sides
Position of patient
Seat the patient at the end of the radiographic table with with the arm and forearm resting on the table. The elbow should be at a 90 DEGREE ANGLE
Structures Shown
This position reduces foreshortening of the scaphoid, which occurs with a perpendicular central ray. It also opens the spaces between adjacent carpals>