Metabolomic technologies including imaging mass spectrometry (IMS; also called mass spectrometry imaging, MSI, or matrix-assisted laser desorption/ionization-mass spectrometry imaging, MALDI MSI) are important methods to evaluate levels of many compounds in brain with high spatial resolution, characterize metabolic phenotypes of brain disorders, and identify disease biomarkers. ATP is central to brain energetics, and reports of its heterogeneous distribution in brain and regional differences in ATP/ADP ratios reported in IMS studies conflict with earlier studies. These discordant data were, therefore, analyzed and compared with biochemical literature that used rigorous methods to preserve labile metabolites. Unequal, very low regional ATP levels and low ATP/ADP ratios are explained by rapid metabolism during postmortem ischemia. A critical aspect of any analysis of brain components is their stability during and after tissue harvest so measured concentrations closely approximate their physiological levels in vivo. Unfortunately, the requirement for inactivation of brain enzymes by freezing or heating is not widely recognized outside the neurochemistry discipline, and procedures that do not prevent postmortem autolysis, including decapitation, brain removal/dissection, and 'snap freezing' are commonly used. Strong emphasis is placed on use of supplementary approaches to calibrate metabolite abundance in units of concentration in IMS studies and comparison of IMS results with biochemical data obtained by different methods to help identify potential artifacts.

代谢组学技术，包括成像质谱（IMS；也称为质谱成像，MSI，或基质辅助激光解吸/电离质谱成像，MALDI MSI）是评估大脑中许多化合物水平的重要方法，具有高空间分辨率，表征脑疾病的代谢表型，并识别疾病生物标志物。ATP 是大脑能量学的核心，IMS 研究中报道的其在大脑中的异质分布和 ATP/ADP 比率的区域差异的报告与早期研究相冲突。因此，对这些不一致的数据进行了分析，并与使用严格方法保存不稳定代谢物的生化文献进行了比较。死后缺血期间的快速代谢解释了不平等的、非常低的区域 ATP 水平和低 ATP/ADP 比率。任何脑成分分析的一个关键方面是它们在组织收获期间和之后的稳定性，因此测量的浓度非常接近它们在体内的生理水平。不幸的是，通过冷冻或加热使脑酶失活的要求在神经化学学科之外并未得到广泛认可，并且通常使用不防止死后自溶的程序，包括斩首、脑切除/解剖和“速冻”。重点强调使用补充方法来校准 IMS 研究中以浓度为单位的代谢物丰度，并将 IMS 结果与通过不同方法获得的生化数据进行比较，以帮助识别潜在的伪影。