When gastric motility is studied, most attention is given to gastric peristalsis. In most studies, gastric diameters were measured at equally distributed points perpendicular to the stomach axis. On the basis of this diameter calculation, peristaltic contractions are detected, and their frequency is calculated [4, 15]. Other authors advocate the use of dark parallel tagging lines that can be applied in the images in the cranio-caudal direction in a manner similar to that described for cardiac MRI. The gap between two tagging lines can be measured, and the distance that a peristaltic wave had passed, by counting the number of tagging lines, can be quantified (Figs. 3 and 4) [3, 29].
Fig. 3 For comparison purposes, T2-weighted and T1-weighted hydro-MR images of subject 1 are shown. a T2-weighted hydro-MR coronal projection image of subject 1: The stomach is loaded with 500 ml of 10% dextrose solution. b T1-weighted coronal projection image of subject 1 24 h later. The stomach is loaded with 500 ml of 10% dextrose solution and 1.0 mM of the contrast agent Gd-DOTA