Use of tissue water as a concentration reference for proton spectroscopic imaging
Use of tissue water as a concentration reference for proton spectroscopic imaging
复制标题
DOI：
10.1002/mrm.20901
复制
发表时间：
2006-06-01
影响因子：
3.3
通讯作者：
Morrison, Leslie A.
中科院分区：
文献类型：
--
作者：
Gasparovic, Charles;Song, Tao;Morrison, Leslie A.
提出了一种在脑部H-1磁共振波谱成像研究中使用组织水作为浓度标准的策略，并对使用该方法时可能产生的潜在误差进行了检验。在较短的回波时间(TES)下，该方法对不同水舱弛豫时间的估计误差的敏感性很小。使用健康受试者的数据表明，通常用于解释部分体积效应的不同图像分割方法(SIPM2、FSL的FAST和K-Means)会导致对代谢物水平的不同估计，特别是在灰质(GM)，这主要是由于对脑脊液(CSF)部分的估计的不同。虽然一致性并不一定验证一种方法，但使用FAST的多光谱分割方法在转基因代谢物的估计中产生了最低的受试者间变异性。用所描述的快速多光谱分割方法获得了这些受试者N-乙酰基(NAC，主要是N-乙酰天冬氨酸)、胆碱(CH)和肌酸(Cr)的平均GM和WM水平：GM[NAC]=17.16+/-1.19 mm；WM[NAC]=14.26+/-1.38 mm；Gm[CH]=3.27+/-0.47 mm；WM[CH]=2.65+/-0.25 mm；Gm[Cr]=13.98+/-1.20 mm；Wm[Cr]=7.10+/-0.67 mm。
A strategy for using tissue water as a concentration standard in H-1 magnetic resonance spectroscopic imaging studies on the brain is presented, and the potential errors that may arise when the method is used are examined. The sensitivity of the method to errors in estimates of the different water compartment relaxation times is shown to be small at short echo times (TEs). Using data from healthy human subjects, it is shown that different image segmentation approaches that are commonly used to account for partial volume effects (SIPM2, FSL's FAST, and K-means) lead to different estimates of metabolite levels, particularly in gray matter (GM), owing primarily to variability in the estimates of the cerebrospinal fluid (CSF) fraction. While consistency does not necessarily validate a method, a multi-spectral segmentation approach using FAST yielded the lowest intersubject variability in the estimates of GM metabolites. The mean GM and white matter (WM) levels of N-acetyl groups (NAc, primarily N-acetylaspartate), choline (Ch), and creatine (Cr) obtained in these subjects using the described method with FAST multispectral segmentation are reported: GM [NAc] = 17.16 +/- 1.19 mM; WM [NAc] = 14.26 +/- 1.38 mM; GM [Ch] = 3.27 +/- 0.47 mM; WM [Ch] = 2.65 +/- 0.25 mM; GM [Cr] = 13.98 +/- 1.20 mM; and WM [Cr] = 7.10 +/- 0.67 mM.