Antral motility measurements by magnetic resonance imaging

Magnetic resonance imaging has been recently proposed as a promising, nonin vasive technique to assess the motility of the gastric antrum. However, so far the reproducibility and dependence on test meal composition has not bee n evaluated. In this study, snapshot echo-planar magnetic resonance imaging was used to measure the frequency, propagation speed and percentage occlus ion of antral contractions in 28 healthy volunteers. They were fed either l iquid (n=12), mixed liquid/solid (n=8) or mixed viscous/solid (n=8) nutrien t (1350 kJ) test meals, and a total of 208 motility measurements were perfo rmed. No effect of meal type on antral motility parameters was observed. An tral contraction frequency was 3.0 +/- 0.2 min(-1) (mean +/- SD, n=164), pr opagation speed was 1.6 +/- 0.2 mm s(-1) (n=164) and the percentage occlusi on was 58 +/- 14% (n=76). Overall, 21% of measurements did not provide usef ul antral motility data, because, in the supine position, the antrum was no t filled by the test meal. Simple methods to overcome this and reduce scann ing time to a minimum are proposed. The results show that the noninvasive m agnetic resonance imaging evaluation of antral motility is accurate and rep roducible and has potential to become a standard tool for such investigatio ns.