An ROI is drawn around the activity in the entire
stomach in anterior and posterior views (or the left
anterior oblique view, if acquired). The ROI should
include any visualized activity in the fundic (proximal)
and antral (distal) regions of the stomach, with
care to adjust the ROI to avoid activity from adjacent
small bowel, if possible. A marker placed on the
patient in a fixed position such as the iliac crest may
be helpful for ensuring reproducibility in gastric
positioning and ROI placement.