Quantification of The Comb Sign in Crohn’s Disease Using Time of Flight Magnetic Resonance Angiography

Abstract

Crohn’s disease (CD) is an inflammatory bowel disease affecting 115k people in the UK. The ‘Comb Sign’ describes increased vascularity and arborization of vessels in the mesentery, due to intestinal inflammation. Radiologists observe this sign on cross-sectional imaging as an indication for CD, but it has never been quantified. We used time of flight MR angiography to visualize the vessels in the abdomen without using contrast agents. Images were analyzed using in-house developed software that traces vessels and counts branching points. Scans from 15 healthy volunteers(HV) and 6 CD patients showed patients had more vessel branching points compared to HV.