Intestinal Transit and Motor Function Studied by Means of MultinuclearMRI (Magnetic Resonance Imaging)

Tobias Hahn
Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland

Abstract:

The aim of this work was to implement acombined fluorine (19F) and proton (1H) Magnetic Resonance Imaging (MRI) framework for the non invasive assessment ofintestinal motor function and transit of non-digestible solids in combination with the acquisition of high-resolution anatomical information. An imaging framework was developed, consisting of biologically inert capsules (length 1.15cm, diameter0.72mm), filled with 140μl perfluoro-[15]-crown-5-ether as 19F marker,a clinical 3T MRI system and a 19F abdominal RF dual surface coil. A dedicated 19F projection imaging sequence allowed capsule tracking with a temporal resolution of 0.133s and spatial resolution of 4mm.The passage of one and two ingested 19F capsules through intestinal sections was monitored in two healthy volunteers. Capsule coordinates were successfully co-registered with anatomical reference scans. Intestinal motility, residence times and lengths as well asforward velocities were determined. Additional in vitro pilot experiments showed that multiple capsule tracking is also feasible by using different 19F markers, i.e.  perfluoro-[15]-crown-5-ether, hexafluorobenzene, perfluorodecalin, and interleaved selective excitation at a temporal resolution of 400ms.By providing the means for real-time multiple capsule tracking and high resolution anatomical imaging, the presented framework has the potential to provide important supplemental information for physiological and pharmaceutical research.