The effect of posture on errors in gastric emptying measurements

Publisher Website
Google Scholar
Abstract
Scintigraphic gastric emptying measurements were made with [human] subjects supine and upright using a dual-detector rectilinear scanner. Variations of the depth of activity were found with both postures. Although there was no significant mean depth change in the group when upright, some individual variations were substantial. Measurements with a .gamma. camera demonstrated similar changes of depth of stomach contents with seated subjects. The variations of attenuation of the emergent radiation lead to appreciable errors in the emptying rates determined by unilateral detection. In .apprx. 1/2 the cases the mean movement of a 99mTc-labeled solid phase marker exceeded 1 cm; this size movement led to an average 20% error in emptying rate determination by an anterior detector. Depth changes of a liquid marker were less marked, exceeding 0.5 cm in 1/2 the subjects; this movement gave rise to an average 6% error when 113mIn was used as the tracer.