| Intestinal ultrasound (IUS) is now considered a promising monitoring tool for the inflammatory bowel disease (IBD) therapeutic strategy. Meanwhile, there still be several challenges. Since the gold standard to assess IBD disease activity is endoscopy, developing IBD-IUS criteria to estimate endoscopic findings is crucial. Also, it is critical to determine if IBD-IUS findings can predict the treatment response and prognosis. In this context, establishing the sonographic improvement/remission concept seems necessary like the endoscopic improvement/remission. From these viewpoints, we are conducting several clinical studies. We developed a new parameter, the submucosa index (SMI), to estimate the endoscopic activity of ulcerative colitis (UC). SMI is defined as the ratio of the submucosal thickness to the total bowel wall thickness (BWT). Our criterion including BWT and SMI demonstrated around 95% positive predictive value for the endoscopic improvement. Also, we observed that the improvement in BWT at 3 months after starting a molecular-targeted medication was associated with steroid-free clinical remission at 6 months in patients with UC. IUS scoring systems for UC, including ours, suggest that some patients achieved endoscopic improvement at 3 months and showed a preferable prognosis. These findings support the notion that IBD-IUS can contribute to earlier clinical decision-making. We believe, at this point, disseminating IBD-IUS in daily practice is necessary for patients' benefits as well as further clinical evidence by multi-center studies. |
