Acute abdominal series


  • Differs from KUB in that patient is upright vs supine on KUB


Medical X-Ray imaging ALP02 nevit.jpg
  • Films
    • Upright chest film: r/o free air
    • Upright abd film: air-fluid levels
    • Supine abd film: width of bowel loops most visible (estimate of amount of distention)
  • Air in colon or rectum makes complete obstruction less likely (esp if symptoms >24hr)
  • If pt does not tolerate upright position left lateral decub abd film can substitute

To differentiate large and small bowel:

  • Small bowel has lines (plica circulares) all the way through the bowel
  • Large bowel has lines (haustra) only halfway through the bowel

Bowel Diameters: 3/6/9 rule

  • Small bowel - 3 cm
  • Colon - 6 cm
  • Cecum - 9 cm

Abdominal x-ray has poor Sn and Sp for SBO

  • If concerned need CT

See Also