Radiologic diagnosis of appendicitis in children

Abstract

Suspected appendicitis is the most common cause of emergency abdominal surgery in children. Because of the often atypical clinical findings, the diagnosis of appendicitis is difficult and may be delayed. Perforation has been reported to occur in 23-73% of children with acute appendicitis. The negative appendectomy rate has been reported to be 15-25%. Since the complication rate is not negligible, it is desirable to avoid unnecessary laparotomies.

The diagnostic accuracy of ultrasonography (US) and additional abdominal computed tomography (CT) was studied in a prospective study that included 600 children. It was found that US is a valuable and highly specific tool in the diagnosis of appendicitis in children. The sensitivity can be increased significantly by performing abdominal CT in addition to US. A negative appendectomy rate of 3.7% and a perforation rate of 21% were achieved.

The diagnostic accuracy of different CT techniques, namely non-enhanced helical CT limited to the lower part of the abdomen, CT of the entire abdomen after intravenously administered contrast medium, and the combination of both, were studied in a retrospective review of prospectively acquired data including 306 CT examinations. It was found that the limited nonenhanced CT had a significantly lower sensitivity than the contrast-enhanced CT, while the combination of both sequences did not further improve the diagnostic accuracy. Hence, the limited non-enhanced scan can be excluded, which results in a reduction of the radiation dose.

The negative appendectomy rate and the perforation rate were studied in a retrospective study including 600 children who underwent appendectomy because of suspected appendicitis during the past decade. A gradual and substantial decrease in the negative appendectomy rate was found during the years studied. The overall perforation rate remained stable, while the rate of perforations after admission appeared to decrease over time. Since nothing was changed in the management of suspected appendicitis apart from the increasing use of US and CT, it may be assumed that the findings result from the preoperative radiologic imaging.

The impact of radiologic imaging procedures, including US only or US and abdominal CT, on the surgeon s decision-making process in the management of suspected appendicitis was studied in a prospective study including 600 children. Radiologic imaging was found to provide valuable guidance as to whether a child with suspected appendicitis should be discharged, observed, or given surgical treatment. Following this guidance may lead to beneficial changes in the management plan. False negative imaging results are infrequent but may still occur and therefore, a close clinical re-examination and communication with the radiologist is of utmost importance for the appropriate final decision.