640层容积CT低剂量全脑灌注评价正常脑血流动力学改变的可行性研究

Feasibility Study of Change in Normal Cerebral Hemodynamics by Low Dose Whole-brain Perfusion with 640 Slice Volume CT

目的评价640层容积CT联合低管电压低浓度对比剂扫描计划对正常脑血流动力学测定的可行性。方法收集临床拟行全脑灌注成像(whole-brain perfusion CT,WB-CTP)的患者120例,选取灌注正常者60例,记录有效辐射剂量(effective dose,ED),同时由2位熟练使用脑灌注后处理软件的影像医师对原始数据进行处理分析,在全脑额叶皮质、颞叶皮质、枕叶皮质、顶叶皮质、额叶白质、颞叶白质、枕叶白质、顶叶白质、基底节区、丘脑分别选取感兴趣区(ROI)由软件自动生成灌注参数,包括局部脑血流量(regional cerebral blood flow,rCBF)、局部脑血流容积(regional cerebral blood volume,rCBV)、平均通过时间(mean transiting time,MTT)、峰值时间(time to peak,TTP),最后进行统计学分析。结果有效辐射剂量为(4.56±0.011)mSv,2名医师测得的各兴趣区的rCBF、rCBV、MTT、TTP值差异无统计学意义(P>0.05)。结论 640层容积CT全脑灌注辐射剂量低、灌注参数稳定、可重复性较好,对于全脑血流动力学的评价较为全面可靠,可为临床提供更加准确的诊断依据。

Objective To evaluate the feasibility of measuring the normal cerebral hemodynamics by low voltages with low concentration contrast medium in 640 slice volume CT.Methods 60 perfusion normal patients were selected from 120 patients who underwent whole cerebral CT perfusion examination.The effective dose（ED）of every patient was recorded and the original data were processed and analyzed by 2 radiologists who were skilled in post processing software of brain perfusion.Region of interest（ROI）was placed on the frontal cortex,temporal cortex,occipital cortex,parietal cortex,frontal white matter,temporal white matter,occipital white matter,parietal white matter,basal ganglia and thalamus.Perfusion parameters were automatically calculated by software,including the regional cerebral blood flow（rCBF）,regional cerebral blood volume（rCBV）,mean transiting time（MTT）and time to peak（TTP）.All data will be statistically analyzed finally.Results The ED was（4.56±0.011）mSv.The rCBF,rCBV,MTT and TTP of every ROI measured by 2 radiologist were not statistically different（P0.05）.Conclusion With the lower radiation,stable perfusion parameters and better repeatability,whole brain perfusion with 640 slice volume CT used to evaluate the normal cerebral hemodynamics is reliable and can serve more accurate diagnosis for clinical.