A New Validated MRI Method for Measuring Colonic Transit Time

Gemma Louise Chaddock¹

We developed a novel MRI technique to measure colonic transit time using MRI marker capsules. We validated this new method against the gold standard X-ray radiopaque markers. 20 subjects took part in the study twice (test-retest). On each study week they swallowed 5 MRI transit marker capsules 24 hours before undergoing an MRI scan. Subjects also undertook the X-ray test, swallowing 20 radiopaque markers on 3 consecutive days with a single abdominal x-ray taken on day 4 as validated in the literature. We found that the MRI transit marker and radiopaque marker results correlated well (Spearmans r= 0.85, p<0.0001).This could provide an alternative test for measuring colonic transit which is simple to carry out and interpret, convenient, non invasive, and does not involve exposure to ionising radiation.