The IBUS Scientific Committee is thrilled to announce the successful application of a 3-years project funded by the Helmsley Foundation: Calculating the Lemann index using intestinal ultrasound.

The Lémann Index (LI) is a recently developed and validated index that assesses and quantitatively measures structural bowel damage over time in patients with Crohn’s disease (CD). However, the requirement of MR enterography to calculate the LI may represent an obstacle for widespread LI implementation, due to inherent limitations of this technique, such as cost, accessibility, and patient acceptability. In addition, in patients with colonic involvement, colonoscopy is needed. The use of intestinal ultrasound (IUS) is an attractive alternative to MRE and colonoscopy, yet needs validation.

In the EXTENT project, we will first run a Delphi consensus with IUS experts, radiologists from ESGAR and investigators involved in the development of the LI, to define damage lesions on IUS equivalent to damage lesions assessed by MRE/colonoscopy. Subsequently, we will perform a cross-sectional study using IUS to measure LI and to compare to conventionally measured LI using MRE. The calculated LI using IUS and the LI calculated using standard examination will be compared for concordance per segment and global organ. The development of an LI-IUS to assess cumulative bowel damage in CD will expand LI implementation in disease modification trials and prospective outcome studies, which will improve the understanding and evaluation of the natural history of CD.