Small-intestinal length measurement on MR enterography: comparison with in vivo surgical measurement

The purpose of this study is to assess the feasibility and accuracy of small-bowel length measurement on MR enterography examinations compared with surgical in vivo measurements.

Thirty-one consecutive patients who were undergoing elective laparotomy for Crohn disease were included in the study. These patients underwent a prior MR enterography examination, and true fast imaging with steady-state precession MR enterography images from the examinations were used to measure small-intestinal length. The MR enterography measurement was compared with a surgical measurement to assess accuracy and correlation.

MR enterography measurements had a significant positive correlation with surgical measurements (r(2) = 0.98; p < 0.001) irrespective of bowel length. The average (± SD) percentage difference between MR enterography and surgical intestinal length measurement was 4.59% ± 0.44%. An average time of 36.5 ± 2.8 minutes was required for bowel length measurement on MR enterography. A significantly longer time was required for measurement of bowel length greater than 300 cm versus shorter bowel length.

Small-bowel length measurements on MR enterography are accurate compared with anatomic measurements. MR enterography can provide an effective noninvasive investigation in planning surgical and nutritional intervention in patients with compromised bowel length.