Oblique Hand Positioning

1Tube Parameters

Exposure: 52 kVp, 2 mAs
SID: 100 cm
Tube Angle: Perpendicular (0°)
Cassette Size: 18x24cm Portrait
Grid: Without Grid

2Patient Preparation

Seat the patient alongside the table. Have them rest their affected arm flat on the table, bringing the hand to the same level as the shoulder. Ensure all radiopaque artifacts (rings, watches, bracelets) are removed.

Trauma Note: If the patient is supine on a trolley/bed, gently slide the detector under the affected hand. Do not force the arm to lay flat if severe injury is suspected.

3Patient Positioning

Initially place the palmar surface of the hand flat against the cassette (PA/DP).
Externally rotate the hand 45 degrees so that the thumb side is raised off the cassette.
Ensure the fingers are separated and resting naturally (use a radiolucent step wedge if available for support).

Trauma Note: If the patient cannot hold the 45-degree angle, utilize radiolucent sponges to build support under the thumb and index finger to maintain the oblique position without causing pain.

4Centering & Marker

Centering: Central ray directed to the 3rd Metacarpophalangeal Joint (MCPJ).
Marker Placement: Place the correct anatomic marker on the lateral (radial) side, oriented AP.

5Collimation

Proximal (Wrist): Collimation should extend approximately 2.5 cm proximal to the radiocarpal joint (wrist).
Distal (Fingers): Include all distal phalanges to the skin margins.
Side to side: Include all lateral and medial skin margins of the hand and thumb.

Image Evaluation Criteria

Coverage: The entire hand must be visualized, from the tufts of the distal phalanges down to 2.5 cm proximal to the wrist joint.
Rotation: A true 45° oblique is evidenced by partial superimposition of the 3rd, 4th, and 5th metacarpal bases and heads, while the 2nd and 3rd remain mostly separated.
Separation: The midshafts of the metacarpals should not overlap. Fingers must be separated to prevent soft tissue/bony superimposition.