FTMS Laboratory for Human Health Research, Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States.
Toxicology Program, Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina 27695, United States.
J Am Soc Mass Spectrom. 2023 Sep 6;34(9):2043-2050. doi: 10.1021/jasms.3c00210. Epub 2023 Aug 1.
Increasing the spatial resolution of a mass spectrometry imaging (MSI) method results in a more defined heatmap of the spatial distribution of molecules across a sample, but it is also associated with the disadvantage of increased acquisition time. Decreasing the area of the region of interest to achieve shorter durations results in the loss of potentially valuable information in larger specimens. This work presents a novel MSI method to reduce the time of MSI data acquisition with variable step size imaging: nested regions of interest (nROIs). Using nROIs, a small ROI may be imaged at a higher spatial resolution while nested inside a lower-spatial-resolution peripheral ROI. This conserves the maximal spatial and chemical information generated from target regions while also decreasing the necessary acquisition time. In this work, the nROI method was characterized on mouse liver and applied to top-hat MSI of zebrafish using a novel optical train, which resulted in a significant improvement in both acquisition time and spatial detail of the zebrafish. The nROI method can be employed with any step size pairing and adapted to any method in which the acquisition time of larger high-resolution ROIs poses a practical challenge.
提高质谱成像（MSI）方法的空间分辨率会导致分子在样品中的空间分布热图更加清晰，但也会带来采集时间增加的缺点。为了缩短采集时间而减小感兴趣区域的面积会导致较大样本中潜在有价值的信息丢失。本工作提出了一种新的 MSI 方法，通过可变步长成像实现 MSI 数据采集时间的缩短：嵌套感兴趣区域（nROI）。使用 nROI，可以在较小的 ROI 内以更高的空间分辨率成像，而较小的 ROI 嵌套在较低空间分辨率的外围 ROI 内。这在保持目标区域生成的最大空间和化学信息的同时，也减少了所需的采集时间。在这项工作中，nROI 方法在小鼠肝脏上进行了表征，并应用于使用新型光学系统的斑马鱼的顶部帽 MSI，这显著提高了斑马鱼的采集时间和空间细节。nROI 方法可以与任何步长组合一起使用，并适用于任何由于较大高分辨率 ROI 的采集时间带来实际挑战的方法。
