Intestinal Ultrasonography as a Tool for Monitoring Disease Activity in Patients with Ulcerative Colitis

Background. Ultrasonography is a noninvasive, inexpensive, and widely available diagnostic tool. In the last two decades, the development of ultrasound techniques and equipment has significantly increased the usage of intestine ultrasound (US) in the assessment of the gastrointestinal tract in patients with inflammatory bowel disease (IBD). Although current guidelines suggest routine utilization of US in patients with Crohn's disease, data regarding US usage in ulcerative colitis are still scarce. We aimed to assess the reliability of intestinal ultrasonography in the assessment of disease activity and extension of patients with ulcerative colitis. Methods. Fifty-five patients with a histologically confirmed diagnosis of ulcerative colitis, treated at University Clinical Center of Serbia in the period from 2019 to 2022 were included in this retrospective observational study. The data were obtained from the patient's medical records including history, laboratory, US, and endoscopy findings. US examined parameters were as following: bowel wall thickness (BWT), presence of fat wrapping, wall layer stratification, mesenteric hypertrophy, presence of enlarged mesenteric lymph nodes, and absence or presence of ascites. Results. Our results suggest that there is a strong correlation of BWT and colonoscopy findings regarding disease extension (r = 0.524, p=0.01, p < 0.05). Furthermore, our results have shown a statistically significant correlation of BWT with the Mayo endoscopic score (r = 0.434, p=0.01, p < 0.05), disease activity score (r = 0.369,p=0.01, p < 0.05), degree of ulcerative colitis burden of luminal inflammation (r = 0.366, p=0.01, p < 0.05), and Geboes index (r = 0.298, p=0.027, p < 0.05). Overall accuracy of US for disease extension and activity was statistically significant (p < 0.05). Conclusions. Our results suggest that US is a moderately accurate method for the assessment of disease activity and localization in patients with UC.