Validation of a Novel 3-Dimensional Sonographic Method for Assessing Gastric Accommodation in Healthy Adults

Objectives-A novel automated 3-dimensional (3D) sonographic method has been developed for measuring gastric volumes. This study aimed to validate and assess the reliability of this novel 3D sonographic method compared to the reference standard in 3D gastric sonography: freehand magneto-based 3D sonography. Methods-A prospective study with 8 balloons (in vitro) and 16 stomachs of healthy volunteers (in vivo) was performed. After a 500-mL liquid meal, 1 preprandial and 3 postprandial volume scans of the stomachs were performed by the novel 3D sonographic method and the current reference-standard 3D sonographic method. Results-The in vitro study showed a mean volume difference between the novel method and the true balloon volume of -1.3 mL; limits of agreement (LoA) were small (-39.3 to 12.3 mL), with an intraclass correlation coefficient (ICC) of 0.998. The in vivo study showed a mean gastric volume of 321 mL between the novel method and the freehand magneto-based method, with a mean volume difference of -4.4 mL; LoA were -40.1 to 31.2 mL, and the ICC was 0.991. The intraobserver and interobserver variability rates were low, at 0.8 mL (LoA, -24.0 to 25.6 mL), with an ICC of 0.995, and 0.5 mL (LoA, of -26.8 to 27.8 mL), with an ICC of 0.999, respectively. Conclusions-The novel 3D sonographic method with automated acquisition showed good agreement with the current reference-standard gastric 3D sonographic method, with low intraobserver and interobserver variability. This novel 3D sonographic method is a valid and reliable technique for determining gastric accommodation.