Three-dimensional dynamic x-ray-computed tomography imaging of stomach motility

The dynamic spatial reconstructor (DSR), an x-ray-computed, tomography-based imaging machine, scans a cylindrical volume up to 39 cm in transaxial diameter and 21.5 cm in axial height with scan repetition rate up to 60 per second. We applied this technique to three dogs in order to investigate the accuracy with which stomach shape, dimensions, and motility can be measured. Single peristaltic waves of one dog's stomach filled with air and two other dogs' stomachs filled with different volumes of contrast-enhanced semisolid meals (10% Gastrografin) were scanned at 2-s intervals at scan apertures between 0.011- and 1-s duration. On completion of the scan sequence, images of oblique sections perpendicular to the local long axis of the stomach fundus, corpus, and antrum were computed from the DSR scan data. Measurements of differential motion of defined points on the stomach wall surface, propagation velocities, acceleration, and amplitudes of peristalsis as well as gastric volume determinations were made. This approach overcomes problems of superposition and ambiguity inherent in projection imaging. Measurements of the volumes of ingested first meal were accurate to within 1.5% (of the actual volume of solid food introduced into the stomach) using a 0.40-s scan aperture. Wall motion could be detected with an SEE of 1.5 mm (pixel size used was 1.4 mm) using a 0.40-s scan aperture.