VIGA (VIrtual GAster): An integrated analysis platform for quantitative assessments of gastric geometry and motility using MRI

BACKGROUND: Current methodologies, such as scintigraphy and gastric manometry, for assessing gastric physiology exhibit notable limitations, particularly in capturing the dynamic changes of the gastric wall during filling and emptying. PURPOSE: To address this gap, we introduce a novel integrated analysis platform named VIGA (VIrtual GAster), designed to quantify stomach geometry and motility using Magnetic Resonance Imaging (MRI). METHODS: The platform, along with its standardized analytical pipeline, was developed and applied to both static and dynamic MRI datasets from 12 healthy individuals after the ingestion of a 600 mL test meal, enabling the evaluation of both morphology and dynamic changes of the stomach wall. Gastric morphology was quantified by measuring the volume and surface geometry of the fundus, corpus, and antrum. Gastric motility was visualized using a comprehensive motility map, from which contraction frequency, amplitude, and speed were derived. RESULTS: The gastric morphology and motility properties can be quantified and visualized interactively on the VIGA platform using individual-specific MRI datasets. The analysis revealed region-specific differences in gastric contractions, with the distal region demonstrating greater occlusion of the contractions (15.8 ± 4.0% in distal stomach vs. 8.9 ± 4.0% in proximal stomach, p < 0.001). Additionally, the distal stomach tended to exhibit higher contraction propagation speed (4.87 ± 1.7 mm/s in distal vs. 4.01 ± 0.9 mm/s in proximal stomach, p = 0.07). Gastric configurations also varied among the compartments, with the fundus having the highest inverse mean curvature: an indicator of the ratio of the wall tension to intragastric pressure (p = 0.003). CONCLUSIONS: The VIGA interface effectively integrates gastric functional assessment using non-invasive imaging, offering potential to advance the clinical evaluation of gastric function in diseases.