磁共振快速扩散峰度成像在脑梗死临床应用的初步研究

摘要

Objective To study the diffusion parameters of ischemic stroke according to the fast magnetic resonance diffusion kurtosis imaging (DKI).Methods Sixty-nine ischemic stroke patients were included in this study.Their fast magnetic resonance DKI data were recorded from 6 h to 6 months after onset of ischemic stroke.The mean kurtosis (MK),mean diffusion (MD) and apparent diffusion coefficiency (ADC) were assayed in infarction and normal sides,their relative change was expressed as rMK,rMD,rADC respectively.Results Diffusion weighted imaging showed homogeneous signals in 35 patients,MK revealed heterogeneous signals in 22 patients and smaller infarctions compared with those revealed in MD.The MK value was significantly higher on infarction side than on normal side in acute and subacute ischemic stroke patients (1.61±0.28 vs 1.00±0.22,1.59±0.47 vs 1.00±0.21,P＜0.01) and was significantly lower on infarction side than on normal side in chronic ischemic stroke patients (0.79±0.24 vs 0.99±0.18,P＜0.01).The amplitude of rMK variation was higher than that of rMD and rADC on infarction side than on normal side in acute and subacute ischemic stroke patients (P＜0.01).Conclusion Fast magnetic resonance DKI can be used in diagnosis of ischemic stroke at different stages and plays a certain role in judging the size of infarction and the severity of ischemic stroke.%目的 本研究应用快速磁共振扩散峰度成像(DKI)序列探究各时期脑梗死患者弥散参数的演变规律.方法 选取2014年11月～2016年2月在首都医科大学宣武医院住院的脑梗死患者69例,于发病6 h～6个月采集1次或多次快速DKI数据,勾画梗死灶范围,测定病变侧及正常侧的平均扩散峰度(MK)、平均扩散系数(MD)及表观扩散系数(ADC),其相对变化率分别用rMK、rMD、rADC表示.结果 在急性期脑梗死患者中,35例患者弥散加权成像显示为均匀高信号,其中22例患者MK显示为不均匀高信号.有29例患者MK显示病灶范围小于MD显示范围.急性期、亚急性期脑梗死患者病变侧MK较正常侧明显升高(1.61±0.28 vs 1.00±0.22,1.59±0.47 vs1.00±0.21,P＜0.01),慢性期病变侧MK则明显低于正常侧(0.79±0.24 vs 0.99±0.18,P＜0.01).急性期、亚急性期病变侧与正常侧比较,rMK变化幅度较rMD、rADC变化幅度大,差异有统计学意义(P＜0.01).结论 快速DKI在诊断各期脑梗死的临床可行性,对临床早期、准确判断梗死灶范围及缺血程度有指导意义.