Penumbral mismatch is underestimated using standard volumetric methods and this is exacerbated with time
Penumbral mismatch is underestimated using standard volumetric methods and this is exacerbated with time
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DOI：
10.1136/jnnp.2008.164947
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发表时间：
2009-09-01
影响因子：
11
通讯作者：
Donnan, G. A.
中科院分区：
文献类型：
--
作者：
Ma, H.;Zavala, J. A.;Donnan, G. A.
背景和目标：使用MR的灌注加权图像（PWI）和弥散加权图像（DWI）之间的不匹配越来越多地应用于治疗试验的患者选择。存在两种计算不匹配体积的方法-常用的体积法和更精确的配准方法，后者考虑了病变拓扑。每种方法分析的不匹配体积存在差异，这些都是时间依赖性的hypothesised.Methods：缺血性卒中发病48小时内的患者基线MR PWI/DWI不匹配和T2结果体积在3个月。体积失配体积定义为PWI减去DWI病变。共配准不匹配体积被定义为PWI缺陷病变不与共配准DWI病变重叠。结果：72例患者的中位年龄为74.0岁。中位基线MR为卒中发作后5.9 h（IQR 3.0，20.4 h）。使用体积法时，不匹配体积出现一致低估（体积中位数9.3 ml，IQR 0，63 ml;配准中位数20.1 ml，IQR 3.2，69.8 ml; p < 0.0001）。这种差异随着卒中发作时间的增加而增加（p = 0.006）。结论：与更精确的配准方法相比，容积分析始终低估了PWI/DWI不匹配的容积。这种影响随着时间的推移而增加。
Background and aim: The mismatch between perfusion weighted images (PWI) and diffusion weighted images (DWI) using MR is increasingly being applied in patient selection for therapeutic trials. Two approaches to the calculation of the mismatch volume exist-the commonly used volumetric and the more precise co-registration method, the latter of which considers lesion topography. That there are differences in the mismatch volume analysed by each method and that these are time dependent was hypothesised.Methods: Patients within 48 h of ischaemic stroke onset had baseline MR PWI/DWI mismatch and T2 outcome volumes at 3 months. Volumetric mismatch volume was defined as PWI minus DWI lesion. Co-registration mismatch volume was defined as the PWI defect lesion not overlapped by the co-registered DWI lesion.Results: 72 patients of median age 74.0 years were studied. Median baseline MR was at 5.9 h (IQR 3.0, 20.4 h) after stroke onset. Consistent underestimation of the mismatch volume occurred using the volumetric method (volumetric median 9.3 ml, IQR 0, 63 ml; co-registration median 20.1 ml, IQR 3.2, 69.8 ml; p < 0.0001). This difference increased with time from stroke onset (p = 0.006).Conclusions: Volumetric analysis consistently underestimates the PWI/DWI mismatch volume compared with the more precise co-registration method. This effect increases with time.