Evolution of water diffusion and anisotropy in hyperacute stroke: significant correlation between fractional anisotropy and T2.
Evolution of water diffusion and anisotropy in hyperacute stroke: significant correlation between fractional anisotropy and T2.
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发表时间：
2004-05
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通讯作者：
Y. Ozsunar;P. Grant;T. Huisman;P. Schaefer;O. Wu;A. Sorensen;W. Koroshetz;R. González
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作者：
Y. Ozsunar;P. Grant;T. Huisman;P. Schaefer;O. Wu;A. Sorensen;W. Koroshetz;R. González
背景和目的我们假设，在急性缺血性脑卒中中，各向异性扩散在T2信号强度没有明显升高时增加，在T2信号强度明显升高时减少。我们的目的是将分数各向异性（FA）测量与中风发作的临床时间、表观扩散系数（ADC）和T2信号强度联系起来。方法对25例患者在症状出现后12小时内进行张量弥散加权成像（dwi）。生成痕量dwi、adc、FAs和回波平面t2加权图像（T2WI）。在dwi上勾勒出卒中和对侧正常感兴趣体积（voi），并将其投影到固有的共配ADC图、FA图和回声平面T2WI上。比较缺血和对侧正常VOIs的平均信号强度，比较ADC、FA和t2wi信号强度的相关变化。结果FA与T2信号强度变化呈显著负相关（r = -0.61, P = 0.009）。FA信号强度与发病时间呈正相关（r = -0.438, P = 0.025）。ADC与FA值无显著相关性（r = -0.302, P = 0.134）。与对侧正常侧相比，同侧缺血体积平均ADC减少31% +/- 11。结论FA变化与T2信号强度呈负相关，与发病时间呈负相关，但与急性期ADC值相关性不强。
BACKGROUND AND PURPOSE We hypothesized that, in acute cerebral ischemic stroke, anisotropic diffusion increases if T2 signal intensity is not substantially elevated and decreases once T2 hyperintensity becomes apparent. Our purpose was to correlate fractional anisotropy (FA) measurements with the clinical time of stroke onset, apparent diffusion coefficients (ADC), and T2 signal intensity. METHODS Tensor diffusion-weighted images (DWIs) of 25 patients were obtained within 12 hours of symptom onset. Trace DWIs, ADCs, FAs, and echo-planar T2-weighted images (T2WI) were generated. Stroke and contralateral normal volumes of interest (VOIs) were outlined on DWIs and projected onto the inherently coregistered ADC map, FA map, and echo-planar T2WI. Mean signal intensity of the ischemic and contralateral normal VOIs were compared for relatives change in ADC, FA, and signal intensity on T2WIs. RESULTS A significant negative correlation was observed between FA and T2 signal-intensity change (r = -0.61, P =.00009). A trend of correlation between FA signal intensity and time of onset were found (r = -0.438, P =.025). No significant correlation was found between ADC and FA values (r = -0.302, P =.134). The mean ADC reduction in the ipsilateral ischemic volume was 31% +/- 11 compared with the contralateral normal side. CONCLUSION Change in FA is inversely correlated with T2 signal intensity and, to a lesser extent, the time of onset, but it is not well correlated with ADC values in the acute stage.