Acute abdominal series

The acute abdominal series is a common set of abdominal radiographs obtained to evaluate bowel gas.

Indications

The acute series is used for a variety of indications including:

• determine the amount of bowel gas, with possible bowel distention
• assess air-fluid levels
• query pneumoperitoneum

Projections

• AP supine view
• PA erect view
• PA erect chest view

The majority of the information is obtained from the AP supine view . The erect view adds more information about air-fluid levels. The erect PA chest radiograph is the more sensitive view for pneumoperitoneum (and chest pathology can sometimes present as abdominal pain).

Some have advocated eliminating the PA erect view from the series . Indeed in the UK the erect abdominal radiograph has virtually disappeared from clinical practice, studies in the 1980s show that the erect projection rarely changed management .

Modified acute series

The following is the modified acute series for patients who are unable to stand.

• AP supine view
• left lateral decubitus view
  • ​most sensitive for evaluating intraperitoneal free gas
• AP supine chest view

Practical points

In order to adequately evaluate for free intraperitoneal gas, the patient should be positioned in the erect and decubitus views for enough time to allow small amounts of free gas to drift up to the diaphragm or lateral liver edge, respectively. This often takes ~5-10 minutes.