Elevations of diffusion anisotropy are associated with hyper-acute stroke: a serial imaging study
Elevations of diffusion anisotropy are associated with hyper-acute stroke: a serial imaging study
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DOI：
10.1016/j.mri.2008.01.015
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发表时间：
2008-06-01
影响因子：
2.5
通讯作者：
Beaulieu, Christian
中科院分区：
文献类型：
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作者：
Bhagat, Yusuf A.;Hussain, Muhammad S.;Beaulieu, Christian
人类缺血性卒中症状发作24小时内的弥散张量成像（DTI）研究报告了弥散各向异性变化的不同发现。24小时内的连续DTI可以澄清这些不均匀的结果。通过分析13例缺血性脑卒中发病的超急性期（2.5 ~ 7 h）和急性期（21.5 ~ 29 h）扫描期离散缺血性脑白质（WM）和灰质（GM）区域扩散各向异性的纵向变化特征。平均弥漫性（MD）、分数各向异性（FA）和t2加权信号强度测量了深部和皮层下WM以及深部和皮层GM区域，这些区域的MD下降幅度为>= 30%。在卒中后超急性期和急性期，所有四个脑区的相对MD平均下降幅度接近40%。总体而言，在症状出现后7小时内，13例患者中有9例在四种组织中至少有一种的FA升高，在同一队列中，13例患者中有1例在中风后21.5- 29it时在缺血性WM和GM区域中至少有一种的FA降低。在深部WM （1.10 +/- 0.11, n=4）、皮层下WM （1.13 +/- 0.14, n=4）、深部GM （1.07 +/- 0.06, n=1）和皮质GM （1.22 +/- 0.13, n=5）的部分患者中，病变相对于对侧的分数各向异性（rFA，平均+/- sd）显著升高。
Diffusion tensor imaging (DTI) studies of human ischemic stroke within 24 h of symptom onset have reported variable findings of changes in diffusion anisotropy. Serial DTI within 24 h may clarify these heterogeneous results. We characterized longitudinal changes of diffusion anisotropy by analyzing discrete ischemic white matter (WM) and gray matter (GM) regions during the hyperacute (2.5-7 h) and acute (21.5-29 h) scanning phases of ischemic stroke onset in 13 patients. Mean diffusivity (MD), fractional anisotropy (FA) and T2-weighted signal intensity were measured for deep and subcortical WM and deep and cortical GM areas in lesions outlined by a >= 30% decrease in MD. Average reductions of similar to 40% in relative (r) MD were observed in all four brain regions during both the hyperacute and acute phases post stroke. Overall, 9 of 13 patients within 7 h post symptom onset showed elevated FA in at least one of the four tissues, and within the same cohort, I I of 13 patients showed reduced FA in at least one of the ischemic WM and GM regions at 21.5-29 It after stroke. The fractional anisotropy in the lesion relative to the contralateral side (rFA, mean +/- S.D.) was significantly elevated in some patients in the deep WM (1.10 +/- 0.11, n=4), subcortical WM (1.13 +/- 0.14, n=4), deep GM (1.07 +/- 0.06, n=1) and cortical GM (1.22 +/- 0.13, n=5) hyperacutely (