Association between pH-weighted endogenous amide proton chemical exchange saturation transfer MRI and tissue lactic acidosis during acute ischemic stroke
Association between pH-weighted endogenous amide proton chemical exchange saturation transfer MRI and tissue lactic acidosis during acute ischemic stroke
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DOI：
10.1038/jcbfm.2011.23
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发表时间：
2011-08-01
影响因子：
6.3
通讯作者：
Lo, Eng H.
中科院分区：
文献类型：
--
作者：
Sun, Phillip Zhe;Cheung, Jerry S.;Lo, Eng H.
缺血组织在开始无氧呼吸后呈酸性，这可能导致组织代谢受损，最终导致严重的组织损伤。虽然主要脑代谢物的变化可以使用基于磁共振（MR）波谱（MRS）的技术来研究，但它们的时空分辨率通常不足以用于快速发展和异质性急性脑卒中病变的常规检查。最近，ph加权磁共振成像（MRI）被提出作为一种评估组织酸中毒的手段，通过探测内源性蛋白质和肽中酰胺质子的ph依赖性化学交换。在这项研究中，我们使用局部质子MRS和多参数成像技术（包括灌注、扩散、pH和弛豫MRI）来表征急性缺血性组织损伤。我们的研究表明，ph加权MRI可以检测出缺血性病变，并且与H-1 MRS测量的组织乳酸含量密切相关，提示乳酸酸中毒。我们的结果也证实了表观扩散系数与乳酸的相关性；然而，灌注、T-1和T-2之间没有明显的关系。总之，我们的研究表明，优化的内源性pH加权MRI，通过对局部组织pH的敏感，仍然是一种有前途的工具，可以提供乳酸酸中毒和组织代谢改变的替代成像标记，并增强传统的中风诊断技术。脑血流与代谢杂志（2011）31,1743-1750；doi: 10.1038 / jcbfm.2011.23;2011年3月9日在线发布
The ischemic tissue becomes acidic after initiation of anaerobic respiration, which may result in impaired tissue metabolism and, ultimately, in severe tissue damage. Although changes in the major cerebral metabolites can be studied using magnetic resonance (MR) spectroscopy (MRS)-based techniques, their spatiotemporal resolution is often not sufficient for routine examination of fast-evolving and heterogeneous acute stroke lesions. Recently, pH-weighted MR imaging (MRI) has been proposed as a means to assess tissue acidosis by probing the pH-dependent chemical exchange of amide protons from endogenous proteins and peptides. In this study, we characterized acute ischemic tissue damage using localized proton MRS and multiparametric imaging techniques that included perfusion, diffusion, pH, and relaxation MRI. Our study showed that pH-weighted MRI can detect ischemic lesions and strongly correlates with tissue lactate content measured by H-1 MRS, indicating lactic acidosis. Our results also confirmed the correlation between apparent diffusion coefficient and lactate; however, no significant relationship was found for perfusion, T-1, and T-2. In summary, our study showed that optimized endogenous pH-weighted MRI, by sensitizing to local tissue pH, remains a promising tool for providing a surrogate imaging marker of lactic acidosis and altered tissue metabolism, and augments conventional techniques for stroke diagnosis. Journal of Cerebral Blood Flow & Metabolism (2011) 31, 1743-1750; doi:10.1038/jcbfm.2011.23; published online 9 March 2011