Department of Neurology, The Royal Melbourne Hospital, Grattan Street, Parkville VIC 3050, Australia.
Neurology. 2010 Sep 21;75(12):1040-7. doi: 10.1212/WNL.0b013e3181f39ab6. Epub 2010 Aug 18.
The use of diffusion-weighted imaging (DWI) to define irreversibly damaged infarct core is challenged by data suggesting potential partial reversal of DWI abnormalities. However, previous studies have not considered infarct involution. We investigated the prevalence of DWI lesion reversal in the EPITHET Trial.
EPITHET randomized patients 3-6 hours from onset of acute ischemic stroke to tissue plasminogen activator (tPA) or placebo. Pretreatment DWI and day 90 T2-weighted images were coregistered. Apparent reversal of the acute ischemic lesion was defined as DWI lesion not incorporated into the final infarct. Voxels of CSF at follow-up were subtracted from regions of apparent DWI lesion reversal to adjust for infarct atrophy. All cases were visually cross-checked to exclude volume loss and coregistration inaccuracies.
In 60 patients, apparent reversal involved a median 46% of the baseline DWI lesion (median volume 4.9 mL, interquartile range 2.6-9.5 mL) and was associated with less severe baseline hypoperfusion (p < 0.001). Apparent reversal was increased by reperfusion, regardless of the severity of baseline hypoperfusion (p = 0.02). However, the median volume of apparent reversal was reduced by 45% when CSF voxels were subtracted (2.7 mL, interquartile range 1.6-6.2 mL, p < 0.001). Perfusion-diffusion mismatch classification only rarely altered after adjusting the baseline DWI volume for apparent reversal. Visual comparison of acute DWI to subacute DWI or day 90 T2 identified minor regions of true DWI lesion reversal in only 6 of 93 patients.
True DWI lesion reversal is uncommon in ischemic stroke patients. The volume of apparent lesion reversal is small and would rarely affect treatment decisions based on perfusion-diffusion mismatch.
弥散加权成像（DWI）用于定义不可逆损伤的梗死核心受到数据的挑战，这些数据表明 DWI 异常存在潜在的部分逆转。然而，之前的研究并未考虑到梗死退缩。我们在 EPITHET 试验中研究了 DWI 病变逆转的发生率。
EPITHET 将发病后 3-6 小时的急性缺血性脑卒中患者随机分为组织型纤溶酶原激活剂（tPA）组或安慰剂组。将预处理 DWI 和第 90 天 T2 加权图像进行配准。急性缺血性病变的明显逆转定义为 DWI 病变未包含在最终梗死中。在随访时，从明显 DWI 病变逆转的区域中减去 CSF 的体素，以调整梗死萎缩。所有病例均进行视觉交叉检查，以排除体积损失和配准不准确。
在 60 例患者中，明显的逆转涉及中位数为 46%的基线 DWI 病变（中位数体积为 4.9mL，四分位间距为 2.6-9.5mL），与基线低灌注程度较轻相关（p<0.001）。无论基线低灌注程度如何，再灌注均可增加明显的逆转（p=0.02）。然而，当减去 CSF 体素时，明显逆转的中位数体积减少了 45%（2.7mL，四分位间距为 1.6-6.2mL，p<0.001）。调整基线 DWI 体积后，灌注-弥散不匹配分类仅在极少数情况下发生改变。在 93 例患者中，仅有 6 例通过将急性 DWI 与亚急性 DWI 或第 90 天 T2 进行比较，发现了真正的 DWI 病变逆转的小区域。
在缺血性脑卒中患者中，真正的 DWI 病变逆转并不常见。明显病变逆转的体积较小，很少会影响基于灌注-弥散不匹配的治疗决策。
