Intestinal Ultrasound, Magnetic Resonance Enterography, and Conventional Assessment Tools Before and After Treatment of Intestinal Behcet's Disease

Background: The "treat-to-target" approach has recently been adopted in the treatment of inflammatory bowel disease (IBD). The basic premise is to define specific measurable targets and then adjust treatment until these targets are achieved and maintained. According to the Selecting Therapeutic Targets in Inflammatory Bowel Disease (STRIDE)-Ⅱ statement published in 2021, the long-term treatment targets for IBD are clinical remission, endoscopic healing, absence of disability, restoration of quality of life, and normal growth in children. Symptomatic relief and normalization of serum and fecal markers were determined as short-term targets. Transmural healing in Crohn's disease and histological healing in ulcerative colitis are not formal targets but should be assessed as measures of the remission depth. While endoscopic examination assesses the mucosal inflammatory status of the bowel wall, transmural inflammatory status needs to be evaluated with ultrasound, computed tomography (CT), or magnetic resonance enterography (MRE). Ultrasound is advantageous as it does not utilize ionizing radiation and is less costly and uncomfortable for patients, allowing more frequent use. Recent studies suggest that intestinal ultrasound is beneficial in treatment response assessment and planning in patients with Crohn's disease and ulcerative colitis. However, there is a paucity of study regarding the effectiveness of intestinal ultrasound in management of intestinal Behcet's disease. Furthermore, despite its accuracy and comprehensive imaging capabilities without radiation risk, MRE has not been widely used in the diagnosis and follow-up of the patients with intestinal Behcet's disease, and no studies have reported changes in MRE findings after treatment.