Technical Evaluation

• Technical evaluation: Film on viewer correctly - to see if right and left sides are the right way round:

  • heart should be 2/3 to the left of midline
  • aortic arch should be to the left of the midline
  • right hemidiaphragm should be a little higher than the left
  • under the left hemidiaphragm there might be a gastric bubble
  • Essential for accurate diagnosis
• Technical evaluation: correct patient / date:

  • check labels
  • Essential for accurate diagnosis and evaluating series of XR
• Technical evaluation: Erect or supine

  • Hemidiaphragms are higher & mediastinum are wider in supine
• Technical evaluation: Projection

  • most X-rays are PA (posterior to anterior), so patients arms are abducted so medial border of scapula are not shown in xray
  • if theyre AP (anterior to posterior) the medial border of scapula will be seen in xray
  • Scapular shadow seen on AP
  • Heart shadow larger on AP
  • May need to modify interpretation
• Technical evaluation: Rotation

  • how to check if patients have rotated during xray:
  • medial borders of clavicles should be in equal distance from the trachea, if not, the patient has rotated
  • Structures appear shifted
• Technical evaluation: Penetration

  • underexposure = too white
  • overexposure = too black
  • should be able to see intervertebral discs above the heart, but not towards the bottom
• Technical evaluation: Depth of inspiration:

  • have to count anterior ribs on right hand side
  • somewhere between 5th and 7th ribs should intercept the hemidiaphragm
  • if the interception is before 5th rib it shows poor lung volume
  • if its after 7th ribs, it shows hyperinflation
• Technical evaluation: Entire chest on film:

  • make sure all of the lungs are visible on the x-ray, Laterally and vertically