Acute abdominal series

Background

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

Diagnosis

Normal

Small bowel obstruction

Upright chest radiograph demonstrating free intra-abdominal air below the diaphragm. (Black arrows demonstrate the air below the diaphragm)

Cecal volvulus. Featureless dilated gas filled viscus, representing the volved caecum, in the left upper quadrant (black arrows) and small bowel obstruction (white arrows). No colonic gas is identified.

Multiple foreign bodies in the bowel; body-packing with multiple "balls" of hashish.

• 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

• SBO