Length of the healthy and pathological small intestine in patients with Crohn's disease: calculations using computed tomography and magnetic resonance enterography.

Many patients with Crohn's disease (CD) require surgical intervention during their lifetime. A correct preoperative assessment of the intestinal length is necessary to predict and quickly treat postoperative nutritional disorders. The aim of this paper is to explain the method used in our hospital to measure intestinal length in patients with CD and its usefulness for making the correct therapeutic decision. Vessel analysis software is used to measure small bowel length through computed tomography enterography (CTE) or magnetic resonance enterography (MRE). The method permits two-dimensional and three-dimensional curved multiplanar reconstructions and allows each loop to be stretched using a point-by-point identification of the intestinal lumen. Subsequently, the software allows the creation of a virtual image, on which the intestinal length is measured linearly. This methodology was tested on three patients; patients 1 and 3 were examined using CTE, and patient 2 was examined using MRE. The outcomes were discussed at a multidisciplinary team meeting (MDT). As a result, surgical ileocolic resection was recommended for patient 1 and medical therapy for patients 2 and 3. Intestinal length measurements have proved vital during MDTs for making appropriate therapeutic decisions.