踝臂指数与CT灌注成像在脑缺血早期的诊断价值

The Early Diagnostic Value of Ankle-brachial Index and Multi-slice CT Perfusion Imaging in the Patients with Ischemia Brain

目的:研究踝臂指数(Ankle-Brachial Index,ABI)和多排CT灌注成像在缺血性脑血管病中的诊断参考价值,从而为脑缺血患者提供更为简便而又快速的筛选和检查方法。方法:入选2010至2013年期间高度怀疑急性缺血性脑卒中病例210例,其中踝臂异常组66例,踝臂正常组144例。入选的所有病例接受多排CT动态容积全脑灌注成像、颅脑CT血管造影及CT灌注成像。对所灌注参数图即脑血流量(CBF)、脑血容量(CBV)、平均通过时间(MTT)、达峰时间(TTP)及延迟(Delay)均由本院高年资医师进行评估,并且通过ABI初步估计颅脑CT灌注异常的阳性预测值、阴性预测值、灵敏度和特异度。结果:入选的全部患者中有136例出现脑灌注异常,表现为MTT、TTP延长,CBV升高、正常或减低,CBF正常或减低。所测得的ABI异常组中,其中有25例脑灌注异常,ABI正常组有86例脑灌注异常,ABI异常组脑灌注阳性率(75.8%,25/33)高于ABI正常组(59.7%,86/144),差异有统计学意义(P=0.039),且ABI异常组的相对MTT、相对TTP大于ABI正常组,差异有统计学意义(P<0.05)。ABI预测颅脑CT灌注异常的阳性预测值、阴性预测值、灵敏度和特异度分别为76.1%、39.3%、35.6%、77.9%。结论:采用多排CT进行动态容积全脑灌注扫描可以早期、全面、准确评价早期脑血管血流动力学的变化,便于检测的ABI对分析评估和判断脑灌注异常有一定的预测价值,联合ABI和多排CT灌注成像扫描可以对脑血管病做到早发现、早诊断、早治疗。

Objective To study the ankle - brachial index （ABI） and multi-slice CT perfusion imaging in the diagnosis of isch- emic cerebrovascular diseases. Methods 210 cases with acute cerebral ischemic stroke highly suspected from 2010 to 2013 were selected and were divided into two groups： the ankle arm abnormal group, 66 cases, and the normal ankle arm group, 144 cases. All patients received multi-slice dynamic volume CT cerebral perfusion imaging, and cerebral CT angiography and CT perfusion imaging. The perfusion parameters, including cerebral blood flow （CBF）, cerebral blood volume （CBV）, mean through time （determined by MTT）, Tmax （TTP） and delayed time （delay）, are assessed by our high qualification doctors. Cran- iocerebral CT focus on abnormal positive predictive value, negative predictive value, sensitivity and specific degrees pre- liminary estimated by ABI. Results Of all patients, 136 cases with cerebral perfusion abnormalities, presenting as MTT and TTP increasing, CBV increasing, normal or reducing, CBF normal or reducing.ABl measured in the abnormal group, 25 cases are with cerebral perfusion abnormalities; in the normal group, 86 cases. The brain perfusion positive rate of the abnormal group （75.8%, 25/33） is higher than that of the normal group （59.7%, 86/144）. ABI difference is statistically significant （P= 0.039）. The relative MTT and relative TTP of the abnormal group is greater than those of the normal group. ABI difference is statistically significant （P〈0.05）. The ABI predict cerebral CT perfusion abnormalities of positive predictive value, negative predictive value, sensitivity and specific degree are 76.1% ,39.3% ,35.6% ,77.9% respectively. Conclusion Using the mul-ti-slice dynamic volume CT cerebral perfusion scan can early, comprehensively and accurately evaluate cerebrovascular hemo- dynamic changes. ABI have predictive value in evaluating and judging cerebral perfusion abnormalities. ABI and multi-slice CT perfusion imaging scan together can help early detection, early diagnosis and early treatment for cerebrovascular diseases.