Evaluation of Arterial Phase MDCT for the Characterization of Lower Gastrointestinal Bleeding in Infants and Children: Preliminary Results

Abstract

The purpose of this study was to prospectively evaluate the accuracy of MDCT for the characterization of occult lower gastrointestinal bleeding in infants and children. MDCT examinations were prospectively performed on 27 patients (2l boys, six girls; age range, 2 months-18 years). Patients with known causes of lower gastrointestinal bleeding were excluded from the study. Nonionic contrast medium was administered in an amount based on body weight. Images were obtained with a 16-MDCT scanner. For the arterial phase the section thickness was 1 mm; beam pitch, 1; and reconstruction interval, 0.7 mm. The scans were examined for abnormal vessels and extravasation of contrast medium. Two radiologists independently reviewed the images. The sensitivity, specificity, and diagnostic accuracy of MDCT were assessed with the pathologic findings or the final diagnosis as the reference standard. Twenty of 27 patients had abnormal MDCT findings: arteriovenous malformation in 17 patients and Meckel's diverticulum in three patients. Contrast extravasation was identified in four patients. Surgery was performed on 13 of the 27 patients, and the diagnosis was otherwise confirmed in two additional patients. In these 15 cases, the sensitivity, specificity, and diagnostic accuracy of MDCT were 82%, 50%, and 74%. The interobserver difference was not significant (McNemar exact test, p = 0.063). MDCT can be used to identify the location and source of lower gastrointestinal bleeding in infants and children.