Fig. 5  a Left: Volunteer in RP inside the 1.5-T whole-body MRI system. Rectangular surface coils were fixed around the abdomen. Right: Three sagittal MR image slices (two proximal and one distal) of a volume scan in RP with outlined stomach wall. Air and meal are indicated in the MR images by arrows (F: feet, H: head, A: anterior, P: posterior). b Left: Volunteer sitting inside the 0.5-T open-configuration MRI system. A send-receive coil was fixed around the abdomen. Right: Three sagittal MR image slices (two proximal and one distal) of a volume scan in SP with outlined stomach wall. Air and meal are indicated in the MR images by arrows (F: feet, H: head, A: anterior, P: posterior)