动脉瘤性蛛网膜下腔出血患者延迟性脑缺血的CT灌注成像评价

CT perfusion imaging evaluation of delayed cerebral ischemia in the patients with aneurysmal subarachnoid hemorrhage

目的探讨CT灌注成像（CTP）在动脉瘤性蛛网膜下腔出血（a SAH）患者延迟性脑缺血（DCI）中的应用价值。方法回顾性分析南京军区南京总医院2015年1至8月诊治的52例a SAH患者资料。所有患者发病6~8 d接受头部CT平扫、CT血管成像（CTA）及CT灌注成像（CTP）一站式检查。采用CTA观察颅内大血管的形态。CTP检查低灌注区域或a SAH周围及其镜像脑实质区域的灌注参数值,包括脑血流量（CBF）、脑血容量（CBV）及平均通过时间（MTT）,计算低灌注区域或a SAH周围脑实质及其镜像脑实质区域的各参数比值,获得相对脑血流量（rCBF）、相对脑血容量（rCBV）及相对平均通过时间（rMTT）。根据有无发生DCI,将患者分为DCI组（12例）及非DCI组（40例）。采用独立样本t检验比较两组低灌注区域或a SAH周围脑实质的rCBF、rCBV及r MTT相对均值的差异。结果 CTA可以显示脑血管痉挛（CVS）。CTP显示DCI组低灌注区域或aSAH周围脑实质的rCBF、rCBV及rMTT分别为0.75±0.22、0.96±0.23及1.6±0.4;非DCI组的r CBF、rCBV及rMTT分别为0.93±0.21、1.01±0.32及1.1±0.3。与非DCI组相比,DCI组rCBF降低、rMTT延长,差异有统计学意义（t_（rCBF）=-3.038,P_（rCBF）=0.004;t_（rMTT）=4.679,P_（rMTT）〈0.01）;两组间r CBV差异无统计学意义（P〉0.05）。结论 rCBF和rMTT值在a SAH后的DCI患者中分别显著降低和延长,对诊断DCI有重要参考价值。

Objective To investigate the application value of CT perfusion imaging （CTP） for delayed cerebral ischemia （DCI） in patients with aneurysmal subarachnoid hemorrhage （aSAH）. Methods The clinical data of 52 patients with aSAH treated in Nanjing General Hospital of Nanjing Military Command from January 2015 to August 2015 were analyzed retrospectively. All patients received head CT scan, CT angiography （CTA） ,and CT peffusion （CTP） imaging within 6-8 days after onset. CTA was used to observe the morphology of large intracranial vessels. The perfusion parameter values of low perfusion region or around aSAH and its mirror brain parenchyma region were examined with CTP, including cerebral blood flow （CBF） ,cerebral blood volume （CBV） ,and mean transit time （MTT）. The ratio of each parameter of low perfusion region or aSAH peripheral brain parenchyma and its mirror image region were calculated. The relative cerebral blood flow （rCBF） ,relative cerebral blood volume （rCBV）, and relative mean transit time （rMTT） were obtained. The patients were divided into a DCI group （n = 12） and a non-DCI group （n = 40） according to whether they had DCI or not. The independent-sample t-test was used to compare the differences of the low perfusion region or the relative mean values of rCBF, rCBV and rMTT of the aSAH peripheral brain parenchyma in both groups. Results CTA could reveal cerebral vasospasm （CVS）. CTP revealed that the low perfusion region or rCBF, rCBV and rMTF of the aSAH peripheral brain parenchyma in the DCI group were 0.75±0.22,0.96±0.23 and 1.6 ±0. 4, respectively; the rCBF, rCBV, and rMTT in the non-DCI group were 0.93±0.21,1.01±0.32 and 1.1±0.3 ,respectively. Compared with the non-DCI group,there were significant differences in the decreased rCBF and prolonged rMTT in the DCI group （ trCBF = - 3.03 8, P,cBv = 0. 004; tMTT = 4. 679, PrMTT = 0. 000）. There was no significant difference in rCBV between the two groups （P〉0.05）. Conclusions The rCBF and rMTT values decreased or prolonged respectively in patients with DCI after aSAH. It has an important reference value for the diagnosis of DCI.