Scaphoid - PA

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Radiographic Positioning


Adult
Other related pages of interest

Name of projection Scaphoid - PA
Area Covered Entire scaphoid bone (wrist)
Pathology shown Fracture, dislocation, foreign body, infection, tumour, arthritis, see scaphoid radiography
Radiographic Anatomy Wrist Radiographic Anatomy
IR Size & Orientation 18 x 24cm
Landscape
Film / Screen Combination Detail
(CR and DR as recommended by manufacturer)
Bucky / Grid No
Filter No
Exposure 52 kVp
2.5 mAs
FFD / SID 100cm
Central Ray Directed to midcarpal area
Perpendicular to IR
Collimation Centre: Midcarpal area
Shutter A: From mid metacarpal to one quarter of the distal radius and ulna
Shutter B: Skin margin
Markers Distal and Lateral
AP orientation
Shielding Gonadal (check your department's policy guidelines)
Respiration Not applicable
Positioning
  • Patient seated at end of table
  • Elbow flexed to 90°
  • Hand pronated (palm down)
  • Hand and forearm resting on table
  • IR under wrist
  • Hand arched to place wrist and carpals close to cassette
Critique

Positioning
  • No rotation of the wrist is demonstrated by:
    • Styloids of radius and ulna are at extreme edges
    • Articulation between the radius and ulnar is open (or slightly super-imposed)
    • Minor super-imposition of the metacarpal bases
  • No foreshortening of distal radius
  • Posterior margin of distal raius projects slightly to obscure radiocarpal joints
  • Carpometacarpal joints 2 through to 5 are open
  • Scaphoid slightly foreshortened
  • Lunate is trapezoidal
  • Long axis of hand, wrist, and forearm is aligned with IR
  • Equal concavity shapes are on each side of the shafts of the proximal metacarpals
  • Near equal distances among the proximal metacarpals
  • Separation of the distal radius and ulna present, except possible minimal superimposition at the distal radioulnar joint
Area Covered
  • Proximal to midmetacarpals, carpals, and distal radius and ulna
Collimation
  • Centre: midcarpal area
  • Shutter A: From mid metacarpal to one quarter of the distal radius and ulna
  • Shutter B: Skin margin
Exposure
  • Bony trabecular patterns and cortical outlines are sharply defined
  • Soft tissues are visualised
  • Sufficient contrast and density to demonstrate the scaphoid fat stripe
Special Notes