Thumb (lateral view)

Dr Aditya Shetty et al.

The thumb lateral view is an orthogonal projection of AP/PA view and helps in the localisation of a foreign body in the thenar eminence, as well as providing valuable information of suspected dislocations.

  • patient is seated alongside the table
  • the forearm is placed on table
  • the wrist is kept in ulnar deviation and thumb abducted
  • lateral aspect of thumb is brought into contact with the cassette by curling fingers (see Figure 1)
  • posteroanterior/anteroposterior projection
  • centring point
    • first metacarpophalangeal joint space
  • collimation
    • laterally to the skin margins
    • distal to skin margin
    • proximal to the carpometacarpal joint 
  • orientation  
    • portrait
  • detector size
    • 18 cm x 24 cm
  • exposure
    • 50-60 kVp
    • 3-5 mAs
  • SID
    • 100 cm
  • grid
    • no

The first digit is positioned laterally, evidenced by open joint spaces and superimposition of the phalangeal and metacarpal heads. 

This position is easily achieved with a gentle internal rotation of the hand until the thumbnail is running perpendicular to the detector. Doing it ulna deviation is the ideal method to attaining an image of high quality, yet previous injuries may prevent the patient from doing it. If the joint spaces are not open, and you have been conservative with raising the hand into the lateral position, you may need to place a small sponge under the patient's hand to maintain a lateral thumb without putting pressure on the hand. If the second metacarpal base is superimposed over the thumb, you have raised the hand too much.  


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Article Information

rID: 29866
Section: Radiography
Synonyms or Alternate Spellings:
  • Lateral view of the thumb

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Cases and Figures

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    Left Thumb Latera...
    Figure 1: left thumb lateral positioning
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    Left Thumb Lateral
    Figure 2: left thumb lateral radiograph
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    Figure 3: lateral view
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