Small Intestine Contrast Ultrasonography

Abstract

Radiology and transabdominal ultrasonography (TUS) are used in the evaluation of the small bowel; however, the former technique is limited by radiation exposure, and the latter by its inability to visualize the entire small bowel. To evaluate the diagnostic accuracy of small intestine contrast ultrasonography (SICUS) to assess the presence, number, site, and extension of small bowel lesions. TUS, SICUS, and small bowel follow-through (SBFT) were performed in 148 consecutive patients (78 women; age range, 12 to 89 yr), 91 with undiagnosed conditions, and 57 with previously diagnosed Crohn's disease (CD). In the undiagnosed patients, the sensitivity and specificity of TUS and SICUS were 57% and 100%, and 94.3% and 98%, respectively. In the CD patients, the sensitivity of TUS and SICUS was 87.3% and 98%, respectively. In comparison with SBFT, the extension of lesions was correctly assessed with SICUS and greatly underestimated with TUS. The concordance index between SBFT and SICUS for the number and site of lesions was 1 and 1 (P < 0.001), respectively, in undiagnosed patients, and 0.81 and 0.83 (P < 0.001), respectively, in CD patients. Between SBFT and TUS, the concordance index was 0.28 and 0.27 (not significant), respectively, in undiagnosed patients, and 0.28 and 0.31 (not significant), respectively, in CD patients. The diagnostic accuracy of SICUS is comparable to that of a radiologic examination, and is superior to that of TUS in detecting the presence, number, extension, and sites of small bowel lesions. These findings support the use of noninvasive SICUS for an initial investigation when small bowel disease is suspected and in the follow-up of CD patients.