Magnetic resonance imaging in the evaluation of the gastric emptying and antral motion: feasibility and reproducibility of a fast not invasive technique

Purpose: The aim of this study was to evaluate reproducibility of a fast MRI protocol to measure gastric emptying and motility of the gastric antrum.

Methods and materials: Gastric emptying and antral speed were measured in 12 type 1 diabetic patients (mean age 43 years) and 9 healthy volunteers (mean age 31 years). Subjects, fasting from 6h, were evaluated in supine position using a 1.5T MR scanner and a eight-channels phased-array body coil after ingestion of 400 ml of a vanillas pudding mixed with 5 ml of Gd-DTPA. Axial 3D T1w sequence at 0 and 30 min for volume evaluation and cine-steady state acquisition every 5 min for a total time of 30 min for gastric wave speed assessing were acquired. Two blinded observers extrapolated T(1/2) from gastric volume assessment and speed of gastric waves.

Results: All the patients tolerated the examination. The T(1/2) cut-off was of 115 min with an accuracy in differentiate controls from diabetics of 96% (95% CI 0.766-0.992; p<0.001), while the antral speed cut-off was of 0.15 mm/s with an accuracy of 87% (95% CI 0.628-0.977; p<0.001). The inter-observer agreement for the volumes at time 0 and 30 min was respectively 0.983 (95% CI 0.9628-0.9929; p<0.001) and 0.9933 (95% CI 0.9847-0.9971; p<0.001) with an agreement of 0.9918 (95% CI 0.9853-0.9954; p<0.001), while for antral speed it was of 0.935 (95% CI 0.9097-0.9528; p<0.001).

Conclusions: MRI is a reproducible technique for the evaluation of gastric emptying and antral motility.