多层螺旋CT脑灌注成像:改良技术及其初步应用

Multislice CT brain perfusion imaging: improved techniques and early clinic experiences

目的探讨多层螺旋CT脑灌注成像改良技术与临床应用价值。方法利用自身对照法对2只健康杂种犬进行了常规和改良4层螺旋CT脑灌注成像(CTP)检查,前者延迟5s、扫描50s,后者分别为8s和40s。14例脑卒中患者行了脑CT灌注成像检查,其中6例采用改良技术。在工作站形成脑血流量(BF)、血容量(BV)、平均通过时间(MTT)等局部脑组织血流动力学参数色阶图,并测量兴趣区这些参数值,以t检验统计分析。结果改良技术获得了满意的CT脑灌注戍像数据,两种方法所得相应犬脑灰质、内囊,基底节组织BF、BV、MTT图类似,数值无显著性差异(p>0．05),改良技术减少球管曝光时间10s。改良CTP还准确揭示了所有患者急性缺血性脑卒中部位、范围与程度。结论CTP改良技术同样有效,并可使辐射损伤减少、球管寿命延长。

Objective To explore the improved techniques of MSCT brain perfusion imaging and its clinical value. Methods Using self- control study method,two healthy hybrid dogs were underwent routine and reformation 4-slice CT brain perfusion imaging.The delayed time and scanning time of routine and improved technique were 5s,50s and 8s,40s respectively. Six of 14 patients with acute ischemic stroke were underwent improved brain CT perfusion, and two also brain CT angiography. The mapping and value of cerebral blood flow （BF）, cerebral blood volume （BV） and mean transit time （MTT） of ROI were analyzed and computed at workstation related the parameters of cerebral hemodynamics. T-test was used in statistical analysis. Results Diagnostic sources data were successfully acquired in all improved CTP scannings. The mapping of BF,BV and MTT of internal capsule（posterior limb）, lentiform nucleus and gray matter （superior temporal gyrus） in dog was similar in both usual and improved CTP. The mean value of BF,BV and MTT in these areas had no significant difference（p〉0.05） in the two CTP methods,and the exposure time of CT tube was decreased 10 seconds every CTP scan in the improved technique.The improved CT brain perfusion imagings accurately detected the site, region and degree of the acute cerebral ischemic nidi in all 6 cases. Conclusion The improved MSCT perfusion imaging has similar diagnostic effects with that of usual CTP, and the radiation-induced injuring will be decreased as well as the tube lifetime will be prolonged.