扩散峰度成像对一氧化碳中毒不同临床时期脑损伤的评估

摘要

目的 探讨扩散峰度成像(DKI)对一氧化碳(CO)中毒不同临床时期脑损伤评估的应用价值.资料与方法 对26例CO中毒急性期、17例迟发性脑病(DNS)期、15例慢性期患者及21名健康志愿者(对照组)行MR平扫、扩散加权成像(DWI)及DKI扫描.比较4组间各感兴趣区DKI参数值,分析各参数值与DWI表观扩散系数(ADC)值的相关性.结果 ①苍白球区平均扩散峰度(MK)值在急性期、DNS期及慢性期分别为1.51±0.15、1.07±0.11和0.59±0.11,急性期明显高于对照组(1.06±0.06,P<0.05),慢性期明显低于DNS期和对照组(P<0.05);与对照组比较,半卵圆中心和胼胝体区MK在急性期和DNS期较高,慢性期较低,且均在DNS期增高最明显(P<0.05).②在各感兴趣区,MK值、平均扩散系数(MD)值均表现为先降低后升高,其中苍白球区MD值在急性期明显低于DNS期和对照组(0.74±0.11比0.85±0.07和0.98±0.12,P<0.05),半卵圆中心、胼胝体在DNS期最小(分别为0.67±0.09、0.80±0.05),明显低于对照组(P<0.05).③不同临床时期各感兴趣区各向异性分数值均呈进行性减低,其中苍白球及半卵圆中心慢性期时达最低(分别为0.19±0.04、0.22±0.03),明显低于DNS期和对照组(P<0.05).④各感兴趣区CO中毒不同临床时期的MD值与ADC值均呈正相关(P<0.01).结论 DKI可以定量评估CO中毒后脑灰白质微结构改变,有利于从微观水平理解CO中毒不同临床时期脑损伤的特点.%Purpose To explore the application value of diffusion kurtosis imaging (DKI) in assessing brain injury in different clinical stages caused by carbon monoxide (CO) poisoning. Materials and Methods MR plain scan, diffusion weighted imaging (DWI) and DKI scans were performed in 26 patients with acute CO poisoning, 17 patients with delayed neuropsychologic sequelae (DNS), 15 patients with chronic phase, and 21 healthy volunteers (control group). The DKI parameter values in regions of interest among the four groups were compared, and the correlation between the values of each parameter and DWI apparent diffusion coefficient (ADC) value was analyzed. Results ①The mean kurtosis (MK) values in the area of pallidum in acute phase, DNS phase, and chronic phase were 1.51±0.15, 1.07±0.11 and 0.59±0.11, respectively; among which the MK value in acute phase was significantly higher than that in the control group (1.06±0.06, P<0.05), and the chronic phase was significantly lower than the DNS phase and the control group (P<0.05); compared with the control group, the MK in centrum semiovale and subcallosal zone was relatively higher in acute phase and DNS phase, lower in chronic phase, both showing the most significant increase in DNS phase (P<0.05). ②In each region of interest, the MK value and mean diffusivity (MD) all showed an increase after decrease. Among them, MD values in the area of pallidum in acute phase were significantly lower than those in DNS and control group (0.74±0.11 vs. 0.85±0.07 and 0.98±0.12, P<0.05), and the centrum semiovale and callosum were the smallest in DNS phase (0.67±0.09 and 0.80±0.05, respectively), significantly lower than that in the control group (P<0.05). ③The fractional anisotropy (FA) values of all regions of interest showed a progressive decrease in different clinical stages, in which pallidum and centrum semiovale were the lowest in chronic phase (0.19±0.04 and 0.22±0.03, respectively), significantly lower than those in DNS phase and the control group (P<0.05). ④There was a positive correlation between MD values and ADC values in different clinical stages of CO poisoning in each region of interest (P<0.01). Conclusion DKI can quantitatively evaluate the changes of brain gray matter microarchitecture after CO poisoning, which is helpful to understand the characteristics of brain injury in different clinical stages caused by CO poisoning from the microscopic level.