P0551 TB or Not TB: The Role of Intestinal Ultrasound in Differentiating Intestinal Tuberculosis from Crohn’s Disease

Abstract Background Intestinal tuberculosis (ITB) and Crohn’s disease (CD) are chronic granulomatous disorders that share many overlapping clinical, endoscopic and histological features, making it difficult to distinguish between the two -especially in TB-endemic regions. IUS has emerged as a valuable, non-invasive tool for assessing and monitoring inflammatory bowel disease, but its role in diagnosing and monitoring ITB and differentiating it from CD remain limited and not yet well established. Methods We report a case series of patients who were treated as ITB based on clinical history, radiological and/or histopathological findings suggestive of TB. All patients underwent baseline IUS in addition to initial colonoscopy evaluations. Results The first case is a 57 year-old who presented with abdominal pain and constitutional symptoms. Her computed tomography of thorax, abdomen and pelvis (CTTAP) reported large mesenteric lymph nodes. Her colonoscopy revealed large and deep circumferential caecal ulcers. IUS demonstrated increased bowel wall thickness (BWT) of caecum and terminal ileum, without hyperaemia. The second case, a 61 year-old who presented with diarrhea and abdominal pain, with colonoscopy showing circumferential ascending colon (AC) ulcers. IUS demonstrated prominent submucosa at AC without hyperaemia. The third patient is a 65 year-old who presented with abdominal pain and constitutional symptoms. Her colonoscopy had circumferential caecal ulcers while CTTAP reported large mesenteric lymph nodes. IUS illustrated increased BWT at caecum with mild hyperaemia. The fourth case is a 65 year-old who presented with chronic diarrhea and abdominal pain. Colonoscopy revealed circumferential caecal ulcers and IUS showed increased BWT at caecum with no hyperaemia. The fifth patient, a 72 year-old who presented with loss of appetite, had a narrowing with ulcerations and friability at 60 cm from anal verge on colonoscopy. IUS demonstrated increased BWT of right colon with loss of wall stratification but no hyperaemia. In all five patients, despite having active inflammation on colonoscopy and presence of increased BWT and mesenteric hyperechogenecity, there was low-grade or absent vascularity on Doppler imaging. This contrasts with CD, where increased mural hyperaemia is typically seen. Conclusion IUS is a valuable, non-invasive imaging modality for evaluating ITB and may help differentiate it from CD based on its characteristic sonographic features. These findings support the role of integrating IUS into routine evaluation of suspected ITB. Incorporating IUS into diagnostic algorithms, particularly in TB-endemic populations such as Malaysia, may help improve diagnostic accuracy and guide in providing appropriate treatment strategies. References: 1. Lee DH, Ko YT, Yoon Y, Lim JH. Sonographic findings of intestinal tuberculosis. J Ultrasound Med. 1993;12(9):537-540. doi:10.7863/jum.1993.12.9.537 2. Sharma R, Madhusudhan KS, Ahuja V. Intestinal tuberculosis versus Crohn’s disease: clinical and radiological recommendations. Indian J Radiol Imaging. 2016;26(2):161-172. doi:10.4103/0971-3026.184417 3. Jain R, Sawhney S, Bhargava DK, Berry M. Diagnosis of abdominal tuberculosis: sonographic findings in patients with early disease. AJR Am J Roentgenol. 1995;165(6):1391-1395. doi:10.2214/ajr.165.6.7484572 4. Hilmi IN, Nik Muhamad Affendi NA, Shahrani S, Thalha AM, Leow AH, Khoo XH. High accuracy of a simplified, practical algorithm in differentiating Crohn’s disease from intestinal tuberculosis. Dig Dis. 2023;41(4):581-588. doi:10.1159/000529238 Conflict of interest: Dr. Shahrani, Shahreedhan: No conflict of interest Alalawi, Maryam: No conflict of interest Hilmi, Ida: No conflict of interest