Hand PA Oblique is a radiography positioning projection of the Upper Extremity. Seated with hand obliqued 45 degrees, radial side raised. SID 40". The centering point is located 3rd MCP joint, with the hand rotated 45 degrees. The central ray is perpendicular to the IR, directed to the 3rd MCP joint. Image-quality criteria include 45-degree oblique: metacarpal midshafts do not overlap, with some overlap of the 3rd, 4th and 5th distal heads, all phalanges, metacarpals, and carpals included. A sample technique is 66 kVp with DR 0.8 or CR 2 mAs, at an SID of 40 inches (102 cm).
Watch the setup
All steps (4)
- Seat the patient at the end of the table with the hand and forearm extended.
- Pronate the hand on the IR, long axis of the hand along the long axis of the IR.
- Rotate the entire hand and wrist laterally 45 degrees, thumb side up.
- Support the hand on a radiolucent step block so the digits are separated and parallel to the IR.
3D anatomy: BodyParts3D, © The Database Center for Life Science. Posed, rendered and labelled by RadTechPrepper. These animations are licensed CC BY-SA 4.0. Credits
Anatomy demonstrated
- Phalanges of all five digits.
- Metacarpals of all five rays.
- Carpal bones of the wrist.
- MCP and IP joint spaces.
Patient preparation
- WARNING: with possible spinal injury or severe trauma, do not attempt to move the patient; do not rotate a severely injured part or remove splints (Bontrager). Merrill's: do not attempt true AP or lateral positioning of a severely injured limb; take two projections 90 degrees apart, moving it as little as possible, and move the IR and tube if the patient cannot reach the position.
- Verify patient identity using two identifiers.
- Remove rings, bracelets, and radiopaque items from the hand.
- Seat the patient at the end of the table with the hand and forearm extended.
- Pronate the hand on the IR, long axis of the hand along the long axis of the IR.
- Rotate the entire hand and wrist laterally 45 degrees, thumb side up.
- Support the hand on a radiolucent step block so the digits are separated and parallel to the IR.
Position & centering point
3rd MCP joint, with the hand rotated 45 degrees.
Central ray
Perpendicular to the IR, directed to the 3rd MCP joint.
Exposure / technique
- kVp
- 66
- mAs
- DR 0.8 / CR 2
- SID
- 40" (102 cm)
- Notes
- Tabletop technique. Radial side raised 45 degrees. Bontrager digital range: 55 to 65 kV; Merrill's chart prints 66 kVp. Sample technique: DR 0.8 / CR 2 mAs at 66 kVp, 40 in SID, for a 5 cm part. Adjust for your equipment.
kVp and mAs are sample values. Use caution when applying them in your department.
Image-quality criteria
- 45-degree oblique: metacarpal midshafts do not overlap, with some overlap of the 3rd, 4th and 5th distal heads.
- All phalanges, metacarpals, and carpals included.
- Joint spaces open and clearly visible.
- Bone trabeculae and soft tissue sharp, no motion blur.
- Collimation: 1 inch on all sides, 1 inch proximal to ulnar styloid.
Common errors
- 1 Hand rotated less than 45 degrees (under-rotated): the metacarpals separate too much.
- 2 Hand rotated more than 45 degrees (over-rotated): the metacarpals overlap too much.
- 3 Digits not parallel to the IR (fingertips down): IP joints closed, phalanges foreshortened.
- 4 CR off-centered clips digits or wrist anatomy.
- 5 Hand rotated less than 45 degrees minimizes the oblique.
- 6 Excess metacarpal overlap means over-rotation; too much separation means under-rotation.
- 7 Fingers flexed or overlapped obscures joint spaces.
- 8 CR not at the 3rd MCP joint.
Clinical indications
- Fractures and dislocations of the phalanges, metacarpals and all joints of the hand.
- Suspected hand joint arthritis or degenerative changes.