Predictors of apparent diffusion coefficient normalization in stroke patients
Predictors of apparent diffusion coefficient normalization in stroke patients
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DOI：
10.1161/01.str.0000114873.28023.c2
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发表时间：
2004-02-01
期刊：
影响因子：
8.3
通讯作者：
Röther, J
中科院分区：
文献类型：
--
作者：
Fiehler, J;Knudsen, K;Röther, J
背景和目的-我们试图描述超急性脑卒中患者表观弥散系数（ADC）值正常化的频率，并识别正常化组织的特征。（包括弥散/灌注成像和MR血管造影）在症状发作后6小时内（平均2.8小时）、24小时后和4 - 7天后再次进行。确定ADC值降低和灌注成像峰值延迟时间的病灶体积。在显示ADC正常化的患者中，通过阈值确定ADC降低分级为对侧值的<50%、50%至60%、60%至70%和70%至80%的体积。将患者分为正常化者（在> 5 mL的组织中表现出ADC正常化，最初ADC降低）或非正常化者（在< 5 mL的组织中表现出ADC正常化）。31例患者中有11例（35.5%）在卒中发作后3小时内首次成像，37例患者中有3例（7.5%）在发作后3 - 6小时成像，均为正常化者。远端血管闭塞患者溶栓治疗后ADC恢复正常主要发生在基底节和白色物质。所有正常化者表现出至少部分组织再灌注。组织与更严重的初始下降，ADC值不太可能表现出normalization.Conclusions - ADC值正常化是不是一个罕见的事件，在急性中风后组织再灌注。ADC值最初降低的脑组织，尤其是在卒中发作后3小时内，可能包括“危险组织”。"
Background and Purpose - We sought to describe the frequency of normalization of apparent diffusion coefficient ( ADC) values that are decreased in hyperacute stroke and to identify characteristics of tissue demonstrating normalization.Methods - Sixty-eight acute ischemic stroke patients underwent MRI examination ( including diffusion/perfusion imaging and MR angiography) within 6 hours ( mean, 2.8 hours) after symptom onset, after 24 hours, and again 4 to 7 days later. Lesion volumes with decreased ADC and delayed time to peak in perfusion imaging were determined. In patients showing ADC normalization, volumes with ADC decrease graded as < 50%, 50% to 60%, 60% to 70%, and 70% to 80% of the contralateral value were determined by thresholding. Patients were categorized as normalizers ( demonstrating ADC normalization in > 5 mL tissue with initially decreased ADC) or nonnormalizers ( demonstrating ADC normalization in < 5 mL tissue).Results - Fourteen patients (19.7%) were classified as normalizers. Eleven of 31 patients (35.5%) initially imaged < 3 hours after stroke onset and 3 of 37 (7.5%) of those imaged 3 to 6 hours after onset were normalizers. ADC normalization occurred predominantly in the basal ganglia and white matter after thrombolytic therapy in patients with more distal vessel occlusions. All normalizers demonstrated at least partial tissue reperfusion. Tissue with more severe initial decrease in ADC was less likely to demonstrate normalization.Conclusions - ADC normalization is not a rare event in acute stroke after tissue reperfusion. Brain tissue with initially decreased ADC, especially within 3 hours after stroke onset, may include "tissue at risk."