AP OBLIQUE WRIST - Anteroposterior Oblique Projection

Exposure Factors

55-60

Kilovoltage (kV)

4-5

Milliampere-seconds (mAs)

Fine Focus

Focus Type

100 cm

Source-to-Image Distance (SID)

No Bucky

Configuration

Optimal parameters: Similar to standard wrist projection but with specific rotation.

Visible Anatomical Structures

This projection specifically highlights the medial column of the carpus:

Pisiform: Observed in profile, separated from the triquetrum.
Hamate (Hook of Hamate): Better visualization of its medial aspect.
Triquetrum: Clearer view of its joint surfaces.
Distal Radio-ulnar Joint: Evaluated from an oblique perspective.
Ulnar Styloid Process: Clearly visible.

Image Receptor Size and Orientation

18 × 24 cm

Portrait (Vertical)

One half of the plate can be used if comparing with another projection.

Patient Positioning

Patient seated at the end of the table.

Forearm resting on the table with the posterior (dorsal) surface against the chassis.

From the AP position, rotate the wrist medially (internally) 45°.

Use a 45° foam wedge to ensure stability and precise angle.

Extend fingers slightly to avoid superimposition over the carpus.

Central Ray Specifications

Perpendicular

Point of Entry: Mid-carpal area (midpoint between the styloid processes).

Direction: Straight to the center of the image receptor.

Collimation: Must include distal radius/ulna and proximal metacarpals.

Acceptable Image Criteria

Rotation

Medial 45° rotation clearly evident.

Separation

Pisiform seen in profile and separated.

Detail

Clear trabecular patterns of carpal bones.

Overlap

Minimum superimposition of the distal ulna.

Clinical Selection: AP vs PA Oblique

AP Oblique (Medial Rotation) is indicated for:

Medial carpal pain (Pisiform, Triquetrum, Hamate).
Evaluation of the Pisiform without superimposition.
Ulnar side trauma of the wrist.
Foreign bodies in the medial area.

PA Oblique (Lateral Rotation) is indicated for:

Lateral carpal pain or trauma.
Suspected Scaphoid or Trapezium fracture.
Osteoarthritis evaluation of lateral joints.
Rhizarthrosis (Trapeziometacarpal arthritis).

Choose based on the location of symptoms or the structures to be evaluated.

AP OBLIQUE WRIST PROJECTION