Displaying and Critiquing Images

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Displaying and CritiquingImages

• Denise Ogilvie
• July 2007

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Display

• Torso, Vertebrae and Head
• Images viewed as if you are facing the patient
• Right side of patient on viewers left
• Left side of patient on viewers right
• AP-marker facing up on the IR
• PA marker facing down on IR

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Display

• Extremities
• As if viewers eyes were the x-ray beam
• Right hand viewed so right thumb toward viewers
  left side
• Marker placed on IR facing up (as in AP for trunk)

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Radiographic Analysis or Critique

• PACEMAN
• Method of critiquing images- devised by Roger
  Windle
• Approach every image you create with this
  technique.

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P

• Patient (part) position is it a true AP,
  Lateral etc, no rotation

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A

• Area covered does it cover adjacent joints etc.
  all anatomy required on the film

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C

• Collimation is it adequate and can it be seen
  on all 4 sides

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E

• Exposure
• Contrast (usually OK when the optimum kVp is set
  black white
• Density correct mAs? see trabecula patterns,
  soft tissue

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M

• Markers correct orientation within collimated
  area, accurate position, straight, level
• Place on IR instead of patient or table less
  distortion- avoid Star Wars placement

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A

• Aesthetically pleasing collimation parallel
  with edge of film, centre of exposed area to
  centre of film, all body parts facing the same
  direction, smallest possible IR, no unwanted
  artefacts

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N

• Name included correct details- Patient name,
  age, date of birth, date of examination,
  facilities name.
• Is the ID plate positioned so it does not obscure
  any anatomy- have ID plate out of collimation
  away from anatomical structures

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Example
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PA Hand

• No rotation
• Open MCP interphalangeal joints
• Slightly separated digits with no soft tissue
  overlap
• All anatomy distal to radius and ulna
• Soft tissue bony trabeculation

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Oblique hand

• Minimal overlap of 3rd-4th and 4th-5th matacarpal
  shafts
• Slight overlap of metacarpal bases heads
• Separation 2nd 3rd metacarpals
• Open interphalangeal MCP joints
• Digits separated slightly with no overlap of soft
  tissues
• All anatomy distal to radius ulna
• Soft tissue bony trabeculation

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Norgaards

• Demonstrate both hands from carpal area to finger
  tips
• Metacarpal heads free of superimposition
• Useful level of density over heads of metacarpals

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PA Wrist

• Demo distal radius ulna, proximal half
  metacarpals
• No rotation
• Soft tissue bony trabeculation
• No excessive flexion to overlap obscure
  metacarpals with digits

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Lateral wrist

• Distal radius, ulna, carpals, proximal half of
  metacarpals
• Superimposed distal radius ulna
• Superimposed metacarpals
• Density similar to PA (compensate for increased
  thickness)

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How to assess rotation?

• Need to select 2 points different distances from
  IR eg styloid processes in lateral wrist
• Place own body part in same position
• Imagine path of X-ray beam eg AP, PA, lat etc
• Decide which way to rotate part to correct
  position

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References

• Lecture notes Roger Windle,2006
• McQuillen Martenson, K,Radiographic image
  analysis,2nd edn
• Ballinger,P,Frank,E, Merrills atlas of
  radiographic positions radiologic procedures,
  10th edn