Aldehyde fixative solutions alter the water relaxation and diffusion properties of nervous tissue.
Aldehyde fixative solutions alter the water relaxation and diffusion properties of nervous tissue.
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醛固定溶液改变了神经组织的水松弛和扩散特性。
DOI：
10.1002/mrm.21977
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发表时间：
2009-07
影响因子：
3.3
通讯作者：
Blackband, Stephen J.
中科院分区：
文献类型：
--
作者：
Shepherd, Timothy M.;Thelwall, Peter E.;Stanisz, Greg J.;Blackband, Stephen J.
化学固定的神经组织非常适合高分辨率、时间密集型MRI采集，而不会出现运动伪影，例如脑图谱项目所需的伪影，但所使用的醛类固定剂可能会显著改变组织MRI特性。为了验证这一假设，本研究描述了常见醛类固定剂对大鼠脑切片模型MRI特性的影响。用4%甲醛浸泡固定的大鼠皮质切片，组织T1和T2分别降低21%和81%（P < 0.001）。通过用磷酸盐缓冲盐水（PBS）洗涤切片12小时以去除游离甲醛溶液来逆转T2减少。使用水扩散的二室分析模型分析的皮质切片的扩散MRI显示，当切片用4%甲醛化学固定时，细胞外表观扩散系数（ADCEX）和表观限制尺寸分别增加88%和30%（P ≤ 0.021）。此外，用4%甲醛固定使跨膜水交换率增加239%（P < 0.001），表明膜渗透性增加。Karnovsky和4%戊二醛固定液也改变了皮质切片的MRI特性，但不同固定液处理之间的差异有显著性（P < 0.05）。所观察到的水松弛和扩散变化有助于更好地定义使用化学固定的神经组织进行MRI研究的有效性和局限性。
Chemically-fixed nervous tissues are well-suited for high-resolution, time-intensive MRI acquisitions without motion artifacts, such as those required for brain atlas projects, but the aldehyde fixatives used may significantly alter tissue MRI properties. To test this hypothesis, this study characterized the impact of common aldehyde fixatives on the MRI properties of a rat brain slice model. Rat cortical slices immersion-fixed in 4% formaldehyde demonstrated 21% and 81% reductions in tissue T1 and T2, respectively (P < 0.001). The T2 reduction was reversed by washing slices with phosphate-buffered saline (PBS) for 12 h to remove free formaldehyde solution. Diffusion MRI of cortical slices analyzed with a two-compartment analytical model of water diffusion demonstrated 88% and 30% increases in extracellular apparent diffusion coefficient (ADCEX) and apparent restriction size, respectively, when slices were chemically-fixed with 4% formaldehyde (P ≤ 0.021). Further, fixation with 4% formaldehyde increased the transmembrane water exchange rate 239% (P < 0.001), indicating increased membrane permeability. Karnovsky's and 4% glutaraldehyde fixative solutions also changed the MRI properties of cortical slices, but significant differences were noted between the different fixative treatments (P < 0.05). The observed water relaxation and diffusion changes help better define the validity and limitations of using chemically-fixed nervous tissue for MRI investigations.
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影响因子：
3.3
作者：
Madi, S;Hasan, KM;Narayana, PA
通讯作者：
Narayana, PA
影响因子：
3.3
作者：
Ma, Y;Hof, PR;Benveniste, H
通讯作者：
Benveniste, H
影响因子：
2.9
作者：
Guilfoyle, DN;Helpern, JA;Lim, KO
通讯作者：
Lim, KO
影响因子：
3.3
作者：
Purea, Armin;Webb, Andrew G.
通讯作者：
Webb, Andrew G.
DOI：
10.1007/s00429-005-0048-y
发表时间：
2005-11-01
期刊：
ANATOMY AND EMBRYOLOGY
影响因子：
--
作者：
Lee, EF;Jacobs, RE;Toga, AW
通讯作者：
Toga, AW