Annu Int Conf IEEE Eng Med Biol Soc. 2021 Nov;2021:3601-3604. doi: 10.1109/EMBC46164.2021.9629601.
Gastric motility has an essential role in mixing and the breakdown of ingested food. It can affect the digestion process and the efficacy of the orally administered drugs. There are several methods to image, measure, and quantify gastric motility. MRI has been shown to be a suitable non-invasive method for gastric motility imaging. However, in most studies, gadolinium-based agents have been used as an oral contrast agent, making it less desirable for general usage. In this study, MRI scans were performed on 4 healthy volunteers, where pineapple juice was used as a natural contrast agent for imaging gastric motility. A novel method was developed to automatically estimate a curved centerline of the stomach. The centerline was used as a reference to quantify contraction magnitudes. The results were visualized as contraction magnitude-maps. The mean speed of each contraction wave on the lesser and greater curvatures of the stomach was calculated, and the variation of the speeds in 4 regions of the stomach were quantified. There were 3-4 contraction waves simultaneously present in the stomach for all cases. The mean speed of all contractions was 2.4±0.9 mm/s, and was in agreement with previous gastric motility studies. The propagation speed of the contractions in the greater curvature was higher in comparison to the lesser curvature (2.9±0.8 vs 1.9±0.5 mm/s); however, the speeds were more similar near to the pylorus. This study shows the feasibility of using pineapple juice as a natural oral contrast agent for the MRI measurements of gastric motility. Also, it demonstrated the viability of the proposed method for automatic curved centerline estimation, which enables practical clinical translation.Clinical Relevance- MRI is able to non-invasively provide dynamic images of the contraction patterns of the stomach, providing a novel clinical tool for assessing functional motility disorders. The use of a natural oral contrast agent such as pineapple juice, as opposed to a gadolinium-based contrast agent, makes MRI more widely accessible. Our semi-automated methods for quantifying contraction magnitude and speed will streamline analysis and clinical diagnosis.
胃动力在混合和消化摄入的食物方面起着重要作用。它可以影响消化过程和口服药物的疗效。有几种方法可以对胃动力进行成像、测量和定量。磁共振成像（MRI）已被证明是一种适合胃动力成像的非侵入性方法。然而，在大多数研究中，都使用钆基造影剂作为口服造影剂，因此不太适合广泛使用。在这项研究中，对 4 名健康志愿者进行了 MRI 扫描，其中使用菠萝汁作为胃动力成像的天然造影剂。开发了一种新的方法来自动估计胃的弯曲中心线。该中心线用作定量收缩幅度的参考。结果以收缩幅度图的形式可视化。计算了胃小弯和大弯上每个收缩波的平均速度，并量化了胃 4 个区域速度的变化。所有情况下，胃中同时存在 3-4 个收缩波。所有收缩的平均速度为 2.4±0.9mm/s，与之前的胃动力研究一致。与小弯相比，大弯收缩的传播速度更高（2.9±0.8 与 1.9±0.5mm/s）；然而，在接近幽门的部位，速度更相似。这项研究表明，使用菠萝汁作为 MRI 测量胃动力的天然口服造影剂是可行的。此外，还证明了所提出的自动弯曲中心线估计方法的可行性，这使得该方法能够在实际临床中应用。临床意义-MRI 能够非侵入性地提供胃收缩模式的动态图像，为评估功能性运动障碍提供了一种新的临床工具。与使用基于钆的造影剂相比，使用菠萝汁等天然口服造影剂使 MRI 更广泛地应用。我们用于量化收缩幅度和速度的半自动方法将简化分析和临床诊断。
