Abdominal X-ray

Pathology

• Ileus
• Volvulus
• Free air
• Calcifications
• Other calcifications/densities

Ileus

Intestinal obstruction (= ileus) is a common problem. Mechanical/obstructive ileus (causes include adhesion, SOL, invagination, volvulus) and paralytic/non-obstructive ileus (causes include trauma, surgery and infection) may be distinguished. In paralytic ileus, all intestinal loops are generally dilated and there is no clear point of obstruction.
Be aware that the diagnosis of ileus is always a clinical diagnosis.
The sensitivity of an AXR in small intestinal ileus is 50% - 66%. Despite its low sensitivity, an AXR may provide an indication of the location of the obstruction.
In an ileus, the intestines will dilate proximal of the point of obstruction. The 3/6/9 rule is a good rule of thumb for pathologically widened intestinal loops. The upper limit of 3 cm applies to the small intestinal loops, 6 cm for the colon and 9 cm for the cecum (blind intestine).