Quantification of the Regional Properties of Gastric Motility Using Dynamic Magnetic Resonance Images.

Goal : To quantify the regional properties of gastric motility from free-breathing dynamic MRI data. Methods : Free-breathing MRI scans were performed on 10 healthy human subjects. Motion correction was applied to reduce the respiratory effect. A stomach centerline was automatically generated and used as a reference axis. Contractions were quantified and visualized as spatio-temporal contraction maps. Gastric motility properties were reported separately for the lesser and greater curvatures in the proximal and distal regions of the stomach. Results : Motility properties varied in different regions of the stomach. The mean contraction frequencies for the lesser and greater curvatures were both 3.1±0.4 cycles per minute. The contraction speed was significantly higher on the greater curvature than the lesser curvature (3.5±0.7 vs 2.5±0.4 mm/s, p<0.001) while contraction size on both curvatures was comparable (4.9±1.2 vs 5.7±2.4 mm, p = 0.326). The mean gastric motility index was significantly higher in the distal greater curvature (28.13±18.89 mm 2 /s) compared to the other regions of the stomach (11.16-14.12 mm 2 /s). Conclusions : The results showed the effectiveness of the proposed method for visualization and quantification of motility patterns from MRI data.