Measurement of Bowel Wall Thickness by Transabdominal Ultrasonography Is Useful to Detect the Inflammation of Colon in Ulcerative Colitis Patients : A Retrospective Study

Abstract Background: Transabdominal ultrasonography (TUS) is a non-invasive method that can be performed repeatedly. Although the usefulness of TUS in ulcerative colitis (UC) has been reported, no well-established data exist yet. This study aimed to determine the usefulness of TUS, compared with colonoscopy (CS), in detecting the presence of mucosal inflammation in each segment of the colon among patients with UC. Methods: Eighty UC patients who underwent US within 14 days after CS were retrospectively registered. We divided the colon into five segments and measured the bowel wall thickness (BWT) using TUS. The results were then compared with the Mayo endoscopic subscore classification (MES) in order to determine their accuracy.Result: We evaluated a total of 268 lesions for each segment among 80 UC patients. The proportion of BWT decreased with an increase in the MES of each segment (p < 0.0001, Cochran-Armitage trend test). The sensitivity, specificity, and accuracy of positive BMT (BWT >2 mm) for detecting mucosal inflammation (MES >0) of each segment were 0.85-1.00, 0.78-0.93, and 0.87-0.98, respectively. Conclusion: This study concluded that TUS was a useful method for detecting the presence or absence of inflammation sites among UC patients due to its high accuracy when BMT >2 mm was considered as a positive finding. This non-invasive method may help control the disease activity of UC.