Department of Neurology, Royal Melbourne Hospital, Grattan Street, Parkville VIC 3050, Australia.
Stroke. 2010 Jan;41(1):82-8. doi: 10.1161/STROKEAHA.109.562116. Epub 2009 Dec 3.
Currently, diffusion-weighted imaging (DWI) lesion volume is the most useful magnetic resonance imaging predictor of hemorrhagic transformation (HT). Preliminary studies have suggested that very low cerebral blood volume (VLCBV) predicts HT. We compared HT prediction by VLCBV and DWI using data from the EPITHET study.
Normal-percentile CBV values were calculated from the nonstroke hemisphere. Whole-brain masks with CBV thresholds of the <0, 2.5, 5, and 10th percentiles were created. The volume of tissue with VLCBV was calculated within the acute DWI ischemic lesion. HT was graded as per ECASS criteria.
HT occurred in 44 of 91 patients. Parenchymal hematoma (PH) occurred in 13 (4 symptomatic) and asymptomatic hemorrhagic infarction (HI) in 31. The median volume of VLCBV was significantly higher in cases with PH. VLCBV predicted HT better than DWI lesion volume and thresholded apparent diffusion coefficient lesion volume in receiver operating characteristic analysis and logistic regression. A cutpoint at 2 mL VLCBV with the <2.5th percentile had 100% sensitivity for PH and, in patients treated with tissue plasminogen activator, defined a population with a 43% risk of PH (95% CI, 23% to 66%, likelihood ratio=16). VLCBV remained an independent predictor of PH in multivariate analysis with traditional clinical risk factors for HT.
VLCBV predicted HT after thrombolysis better than did DWI or apparent diffusion coefficient volume in this large patient cohort. The advantage was greatest in patients with smaller DWI volumes. Prediction was better in patients who recanalized. If validated in an independent cohort, the addition of VLCBV to prethrombolysis decision making may reduce the incidence of HT.
目前，弥散加权成像（DWI）病变体积是预测出血转化（HT）最有用的磁共振成像预测指标。初步研究表明，极低脑血容量（VLCBV）可预测 HT。我们通过 EPITHET 研究的数据比较了 VLCBV 和 DWI 对 HT 的预测能力。
从非中风半球计算正常百分比 CBV 值。创建全脑掩模，CBV 阈值分别为<0、2.5、5 和 10%。在急性 DWI 缺血性病变内计算 VLCBV 组织的体积。HT 根据 ECASS 标准进行分级。
91 例患者中有 44 例发生 HT。实质血肿（PH）发生在 13 例（4 例有症状），无症状性出血性梗死（HI）发生在 31 例。PH 患者的 VLCBV 中位数明显更高。在受试者工作特征分析和逻辑回归中，VLCBV 预测 HT 的能力优于 DWI 病变体积和阈值表观扩散系数病变体积。截断值为 2 mL VLCBV 和<2.5 个百分位数，对 PH 的敏感性为 100%，并且在接受组织型纤溶酶原激活剂治疗的患者中，定义了 PH 风险为 43%的人群（95%CI，23%至 66%，似然比=16）。在多变量分析中，VLCBV 仍然是 PH 的独立预测因子，与 HT 的传统临床危险因素相关。
在这个大型患者队列中，VLCBV 预测溶栓后 HT 的能力优于 DWI 或表观扩散系数体积。在 DWI 体积较小的患者中优势最大。在再通的患者中预测效果更好。如果在独立队列中得到验证，在溶栓前决策中增加 VLCBV 可能会降低 HT 的发生率。
