Correspondence (letter to the editor): Ultrasound First

The following is a direct quotation concerning ultrasound from the cme paper on ileus: “It plays a less important role in the evaluation of ileus, as its utility is limited by artifacts from air in the distended abdomen.” This is incorrect: many publications rate ultrasound (US) and computed tomography (CT) imaging as equally good (2).

The only available meta-analysis (3) clearly finds that plain abdominal radiograph is inferior, so it should no longer be relied upon. The sensitivity and specificity for CT were 87% (83 to 90) and 81% (74 to 87) respectively. The corresponding figures for US were 97% (92 to 99) and 90% (84 to 95) respectively.

This finding is unsurprising, as the criteria underlying US and CT findings are almost identical (4). US requires no orally or anally administered contrast medium and is the only method able to visualize peristalsis in vivo. This means that US can provide a diagnosis several hours earlier than CT and can detect the causes of intestinal occlusion very effectively during this phase, at this time largely unaffected by intestinal gas. This is more difficult only in advanced ileus, due to increasing gas formation. The diagnostic potential of CT using intravenous contrast is increasingly matched by sensitive color Doppler and intravenous contrast-enhanced ultrasound without contraindications.

US and CT are the methods of choice for the diagnosis of ileus. Ultrasound should be used as the first-line method, as it is a repeatable at any time, can be performed at the patient’s bedside, and is free of radiation. In addition, primary X-ray is not indicated on the strength of an “indication that justifies it.”

The lack of importance attached to US for ileus in this publication (1) may be a consequence of both an insufficient literature research and a lack of personal experience of such examinations on the part of the authors.

References