In vivo colon wall imaging using endoluminal coils: feasibility study on rabbits

PURPOSE: To assess in vivo distal colon wall magnetic resonance imaging (MRI) feasibility on rabbits using an endoluminal radio frequency (RF) coil on a 1.5-T clinical scanner. MATERIALS AND METHODS: The endoluminal coil signal-to-noise ratio (SNR) was compared to a clinical four-element phased-array body coil. High-resolution (HR) MRI of rabbit colon walls was performed on six rabbits. The imaging protocol combined T1-weighted fast low-angle-shot (FLASH) sequences with and without fat saturation (FS), T2-weighted True-Fast imaging with steady state precession (Fisp), turbo spin-echo (TSE), and T1-weighted FLASH FS after contrast media injection. Images were compared to histological sections. Catheter tracking using an endoluminal coil in addition to external coils was also evaluated on two rabbits. RESULTS: HR images allow visualization and identification of rabbit colon wall layers. Real-time tracking allows a clear visualization and a good positioning of the endoluminal coil within the rabbit. CONCLUSION: Compared to a clinical multielement array coil, a dedicated endoluminal RF coil provides an important SNR increase at the region of interest (ROI). Very HR images of in vivo rabbit colon walls were achieved providing detailed information on the different wall layers. This technique could be considered on humans for accurate tumoral and inflammatory bowel disease diagnosis.