Patient Factors

• What patient factors influence required radiographic technique?

  • size and shape (body habitus)
  • anatomy density (thickness)
  • pathology
  • composition (chest vs abdomen)
• Sthenic


  “strong, active”. Average size
• Hyposthenic


  thin but healthy in appearance
• Hypersthenic

  large framed and usually overweight
• Asthenic


  small, frail, emaciated and often elderly
• The thicker the patient the more x-rays are needed to penetrate to expose the image receptor
• kV is based on body part thickness
• Do not guess thickness use calipers
• Composition Measuring the thickness of a part doesn’t automatically release the technologist from excercising some additional judgement when selecting the proper technical factors
• Chest

  • lung (air), ribs (bone), heart (muscle)
  • high contrast: black/white minimal grays
• Abdomen

  • stomach, bowels, liver, kidney, spleen, pancreas, diaphragm, urinary, bladder
  • low contrast: many shades of gray
• Radiopaque

  • difficult to penetrate
  • bone, metal
• Radiolucent

  • easy to penetrate
  • air, soft tissue
• Pathology type,size, and composition will influence radiographic technique
• Obtaining good patient history and previous exams will help assessment
• destructive process causing tissues to be more radiolucent ex) osteoporosis
• constructive in increase mass density and composition ex) osteopetrosis