经颅多普勒超声引导下后循环慢性脑缺血CT灌注成像研究＊

目的：探讨经颅多普勒超声引导下后循环慢性脑缺血CT灌注成像的临床应用价值。方法：收集2010-2012年在本院神经内科拟诊为后循环缺血患者60例，使用EMS-9EB×2P（双通道四深度）TCD仪分别评价基底动脉（BA）、大脑后动脉（PCA）、椎动脉（VA）的血流情况，使用Siemens 16排CT对观察组、对照组进行常规平扫，选取以环池层面为中心的感兴趣区进行灌注扫描，应用Siemens自带PCT专用软件包进行后处理，测定灌注参数CBF、CBV、MTT、TTP。结果：TCD：观察组30例患者基底动脉（BA）异常17例，大脑后动脉（PCA）异常3例、椎动脉（VA）异常12例，各条动脉Vm、PI值与对照组比较差异有统计学意义（P〈0.05）。观察组与对照组全部CT平扫未见与临床症状相关的病灶；CT灌注成像观察组中28例显示后循环共32处低灌注区，灌注参数rCBF、rCBV、MTT、TTP经与对照组比较，差异有统计学意义（P〈0.05）。结论：应用简便快捷而又经济无创的TCD和多层螺旋CT设备，可以为临床医生提供慢性PCI患者的定位、定性和定量诊断依据，以此提高慢性PCI早期诊断的准确性，便于尽早给予针对性治疗，预防缺血区域的进一步发展和脑梗死的发生，减少患者功能障碍和残疾发生率，具有重要的临床应用价值。

CT Perfusion in Evaluation of Chronic Posterior Circulation Ischemia by Transcranial Doppler-guided

Objective：To explore the clinical application value of CT perfusion in chronic cerebral posterior circulation ischemia（PCI）guided by transcranial Doppler ultrasound. Method：60 cases of patients with PCI by neurology examination were collected in our hospital from 2010-2012. EMS-9EB×2P（dual-channel four-depth）TCD was used to measure the blood flow conditions of the subjects’basilar artery（BA）,posterior cerebral artery（PCA）and vertebral artery（VA）. 30 subjects tested to have abnormal circulation blood flow were labeled as observation group and 30 subjects with neither neurologic nor posterior circulation blood flow abnormalities were set as CT perfusion control group. All subjects received plain CT scan with Siemens 16-slice spiral computed tomography. Then cisterna ambiens level was used as the center for CT perfusion and Siemens software package was used to post-process and measure CT perfusion parameters including CBF,CBV,MTT,TTP. Result：（1）TCD：of the 30 subjects in the observation group, 17 cases had BA blood flow abnormality,3 cases had PCA blood flow abnormality and 12 cases had VA blood flow abnormality. The differences of Vm、PI between the observation group and the control group were statistically significant（P〈0.05）.（2）No focus related to clinical symptoms was found in all subjects received plain CT scan in the observation group and the control group;32 cases low perfusion areas of posterior circulation were found in 28 cases in the observation group. The differences of CT perfusion parameters including rCBF、rCBV、MTT、TTP between the two groups were statistically significant（P〈0.05）. Conclusion：The use of TCD and multi-spiral CT devices which are simple,convenient,economical and non-invasive has significant clinical application value as it can provide qualitative and quantitative data to help doctors locate and determine chronic PCI and improve the accuracy of its early diagnosis. It also enables doctors to give targeted treatment timely to prevent the deterioration of the ischemic areas and the occurrence of cerebral infarction as well as to reduce the occurrence rate of dysfunction and disability among patients.