基于最大斜率模型脑CT灌注量的改良算法

An improvement method of regional cerebral blood flow assessment by perfusion CT study based on maximal slope model

目的改进常用对比剂流率(<5.0ml/s)下基于最大斜率模型的脑CT灌注量的计算方法。方法8名健康志愿者行脑部多层螺旋CT灌注成像检查。分别利用机配灌注分析软件(传统法)和自编灌注分析软件(改良法)计算正常人脑灰、白质的rCBF,并进行比较。结果改良法和传统法得出的正常脑灰质的rCBF分别为(70.01±7.64)ml·min-1·100g-1、(34.85±1.82)ml·min-1·100g-1,两种方法间差异具有显著性统计学意义(t=12.64,P<0.01);改良法和传统法得出的正常脑白质的rCBF分别为(24.85±3.72)ml·min-1·100g-1、(12.88±1.75)ml·min-1·100g-1,两者差别亦有显著性统计学意义(t=8.23,P<0.01)。结论改良后算法可弥补在常用对比剂流率下传统方法的缺陷,测得的rCBF更接近于实际值。

Objective To improve the conventional method of quantitative assessment of regional cerebral blood flow （rCBF） by a perfusion CT study based on maximal slope model at the general infusion rate （〈5.0 ml/s）. Methods Multislice CT perfusion imaging studies were performed in eight healthy adult volunteers. Regional cerebral flows of the gray matter and the white matter were calculated, respectively with dedicated perfusion software of the scanner （the conventional method） and our self-made software （the improved one）. Results Normal rCBFs calculated with our improved method and with the conventional one were （70.01±7.64） ml · min^-1· 100 g^-1, （34.85±1.82） ml · min^-1· 100 g^-1, respectively in the gray matter. Normal rCBFs in the gray matter had significant difference between two methods （t = 12.64, P〈0. 01）. Normal rCBFs calculated with our improved method and with the conventional method were （24.85±3.72） ml · min^-1· 100 g^-1, （12.88±1.75） ml · min^-1 · 100 g^-1, respectively in the white matter. The normal rCBFs in the white matter showed significant difference between two methods （t= 8.23, P〈0.01 ）. Conclusion The improved method can efficiently remedy the limitation of the conventional method, with which normal rCBFs are more accurate.