Temporal relationship between apparent diffusion coefficient and absolute measurements of cerebral blood flow in acute stroke patients
Temporal relationship between apparent diffusion coefficient and absolute measurements of cerebral blood flow in acute stroke patients
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DOI：
10.1161/01.str.0000048151.28173.0d
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发表时间：
2003-01-01
期刊：
影响因子：
8.3
通讯作者：
Hsu, CY
中科院分区：
文献类型：
--
作者：
Lin, WL;Lee, JM;Hsu, CY
背景和目的-弥散加权成像(DWI)已被确定为急性缺血性脑损伤的标志。我们试图确定急性卒中患者脑血流量(CBF)和表观弥散系数(ADC)之间的关系，并探讨从MRI采集到症状出现的时间是否会改变这种关系。方法：对16例急性卒中患者进行弥散加权成像(DWI)和灌注加权成像，计算ADC和CBF。ADC值被归一化(NADC)到对侧的非缺血半球，然后在异常通过时间定义的感兴趣区域内逐个像素地与CBF相关。为探讨脑血流量与脑血流量之间关系的时间效应，将患者按症状出现至磁共振成像的时间长短分为2组进行数据分析：A组2~4小时(n=8)，B组4.5~6.5小时(n=8)。在逐渐下降之后，NADC突然下降到21毫升的CBF阈值以下。分钟(-1)。100g(-1)。当受试者被分为早期和晚期显像组时，较早成像的患者组(A组)的阈值较低(15毫升)。分钟(-1)。100g(-1)，比造影组晚(B组，24mL)。分钟(-1)。100g(-1)。结论：我们的结果表明，在脑缺血时，NADC和CBF之间存在一定的关系，ADC值本身可能为预测脑血流灌注状态提供有用的信息。然而，这种关系可能会随着卒中发病和成像之间的时间推移而改变。
Background and Purpose-Diffusion-weighted imaging (DWI) has been established as a marker of acute ischemic brain injury. We sought to determine the relationship between cerebral blood flow (CBF) and apparent diffusion coefficient (ADC) and to explore whether the elapsed time between MRI acquisition and symptom onset alters this relation in acute stroke patients.Methods-Sixteen acute stroke patients were studied with DWI and perfusion-weighted imaging, from which ADC and CBF were calculated. ADC values were normalized (nADC) to the contralateral, nonischemic hemisphere and then correlated pixel by pixel with CBF within a region of interest defined by abnormal transit time. To explore potential temporal effects on the relationship between CBF and nADC, patients were divided into 2 groups based on the duration between symptom onset and MR imaging for data analysis: group A, 2 to 4 hours (n=8), and group B, 4.5 to 6.5 hours (n=8).Results-nADC was plotted against CBF for each pixel in all 16 subjects, and a composite relationship was derived. After a gradual decline, an abrupt drop in nADC occurred below a CBF threshold value of 21 mL . min(-1) . 100 g(-1). When subjects were divided into early and late imaging groups, the group of patients imaged earlier (group A) had a lower threshold (15 mL . min(-1) . 100 g(-1)) than the group imaged later (group B, 24 mL . min(-1) . 100 g(-1)).onclusions-Our results demonstrate that a relationship between nADC and CBF exists in the ischemic brain and that ADC values alone may provide useful information in predicting perfusion status. However, this relationship may change with elapsing time between stroke onset and imaging.