- Fracture of distal radius or ulna or isolated fractures of radial or ulnar styloid processes, as well as fractures of individual carpal bones, are demonstrated. Some pathologic processes, such as osteomyelitis and arthritis, also may be demonstrated.
Technical Factors:
- IR size- 18 x 24 cm (8 x 10 inches)
- Division in half, crosswise
- Detail screen, tabletop
- Digital IR - use lead masking
- 60 or add upto 6kv range
Shielding:
- Place lead shield over patient's lap to shield gonads.
Patient Position:
- Seat patient at end of table, with elbow flexed about 90degrees and hand and wrist resting on cassette, palm down.
Part Position:
- Align and center hand and wrist to portion of IR that is being exposed.
- From pronated position, rotate wrist and hand laterally 45degrees.
- For stability, place a 45degrees support under thumb side of hand to support hand and wrist in a 45degrees oblique position (fig. 5-91), or partially flex finger to arch hand so that fingertips rest lightly on cassette (fig. 5-90).
Central Ray:
- CR perpendicular to IR, directed to midcarpal area
- Minimum SID of 40inches (100cm)
Collimation:
Collimate to wrist on four sides; include distal radius and ulna and the mid-metacarpal area, at least.
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Radiographic Criteria:
Structure Shown:
- Distal radius, ulna, carpals, and at least to mid-metacarpal area are visible
- The trapezium and scaphoid should be well visualized, with only slight superimposition of other carpals on their medial aspects.
Position:
- Long axis of the hand, wrist, and forearm should be align with IR.
True 45degrees oblique of the wrist is evidenced by the following:
- Ulnar head partially superimposed by distal radius;
- Proximal third through fifth metacarpals (metacarpal bases) should appear mostly superimposed.
Collimation and CR:
- Collimation should be visible on four sides to area of affected wrist.
- CR and center of collimation field should be to midcarpal area.
Exposure Criteria:
- Optimal density and contrast with no motion demonstrate the carpals and their overlapping borders, soft tissue margins, and clear, sharp bony trabecular markings.
