ACUTE ABDOMEN RADIOLOGICAL IMAGING

acute abdomen radiological imaging : Ultrasound has an increasingly important role in the initial evaluation of the acute abdomen. Many trauma centres recognize the value of ultrasound as a first-line investigation in properly trained hands. Small portable scanners now offer bedside—even roadside—assessment that can speed the triage process, whereas higher-specification scanners enable the experienced operator to diagnose detailed pathology in the acute abdomen. CT also has an increasing role in this situation. It is readily available in most centres and is proven to be highly accurate. But CT is static, takes longer to arrange and perform and is not always possible, particularly in acutely ill and unstable patients.

There is little doubt that the accuracy of the ultrasound scan is directly attributable to the skill and experience of the operator. For instance, a detailed knowledge of the anatomy, and therefore potential communications, of the peritoneal and retroperitoneal fascial spaces is essential in order to understand the significance and likely origin of an abdominal fluid collection. A left iliac fluid collection may simply be due to local causes such as a diverticular abscess, but could be the result of fluid tracking from a leaking aortic aneurysm or an acutely inflamed or ruptured pancreas.

One other significant advantage of ultrasound is that it is usually an ‘interactive’ process. In the acute setting, the simple question ‘Where does it hurt?’ will frequently direct the operator to the underlying pathology, for example in acute bowel inflammation or acute cholecystitis. Clinical signs, such as erythema ab igne, which results from pain relief by the patient applying a hot water bottle to the symptomatic area, may also help to focus the examination. The operator should be alert to potential clues and be prepared to step outside standard scanning protocols, adapting to the many possible presentations of trauma or other acute abdominal conditions.