多b值扩散加权成像在阿尔茨海默病临床诊断中的价值探讨

Clinical diagnosis value of multi-b value diffusion weighted imaging in Alzheimer's disease

目的探讨多b值扩散加权成像(multi-b value diffusion-weighted imaging,MB-DWI)技术在阿尔茨海默病(Alzheimer's disease,AD)临床诊断中的价值,以期协助临床对AD早期阶段进行诊断及治疗。材料与方法本研究总共纳入68名受试者,包括AD患者24名(AD组)、轻度认知障碍(mild cognitive impairment,MCI)患者29名(MCI组)和正常对照(normal control,NC)15名(NC组)。对比三组间表观扩散系数(apparent diffusion coefficient,ADC)、体素内不相干运动成像扩散系数(intravoxel incoherent motion-diffusion coefficient,IVIM-D)、体素内不相干运动成像灌注分数(intravoxel incoherent motion-perfusion fraction,IVIM-f)、水通道蛋白相关表观扩散系数(aquaporin-apparent diffusion coefficient,AQP-ADC)差异是否具有统计学意义,并进行临床相关认知评分与上述指标的相关性分析。结果在使用AQP-ADC值、IVIM-D值分析中发现MCI组和NC组的差异主要在额叶皮层(右P=0.046;左P=0.016)、海马(右P=0.020;左P=0.022)、丘脑(右P=0.022;左P=0.001)及左侧颞叶(P=0.049)。且随着AD疾病的进展,与NC组相比,AD组表现出更多部位的显著差异。在使用受试者工作特性(receiver operating characteristic,ROC)曲线分析MB-DWI相关指标的诊断性能时,发现相较于常规ADC,AQP-ADC、IVIM-D在检出MCI、AD上具有优越性。结论相较于常规DWI,MB-DWI对AD的诊断具有明显的优越性,特别是提供了MCI阶段的额外信息。MB-DWI可能成为AD相关病理生理改变的另一个早期生物标志物和疾病进展的衡量指标。

Objective:To explore the value of multi-b diffusion-weighted imaging(MB-DWI)in the clinical diagnosis of Alzheimer's disease(AD),in order to assist clinical diagnosis and treatment in the early stage of AD.Materials and Methods:A total of 68 subjects were enrolled in the study,including three subject populations:24 subjects with AD,29 subjects with cognitive impairment(MCI),and 15 normal controls(NC)with no cognitive complaints.Statistical differences in apparent diffusion coefficient(ADC),intravoxel incoherent motion-diffusion coefficient(IVIM-D),intravoxel incoherent motion-perfusion fraction(IVIM-f),aquaporin-apparent diffusion coefficient(AQP-ADC)were compared using one-way ANOVA or Cruskal-Wallis test,and further comparison between groups was performed using Bonferroni method.In addition,the correlation between clinical cognitive score and the above indexes was further analyzed.Results:In the analysis of AQP-ADC and IVIM-D,the differences between the MCI group and the NC group were mainly in the frontal cortex(right P=0.046;left P=0.016),hippocampus(right P=0.020;left P=0.022),thalamus(right P=0.022;left P=0.001)and left temporal white matter(P=0.049).The results showed that compared with the NC group,the AD group showed more regional differences in the progression of AD.In addition,AQP-ADC and IVIM-D had superiority in detecting MCI and AD compared with conventional ADC when receiver operating characteristic curves(ROC)were used to analyze the diagnostic performance of MB-DWI related indexes.Conclusions:Compared with conventional DWI,MB-DWI has significant advantages in AD diagnosis,especially in providing additional information at the MCI stage.MB-DWI may be another early biomarker and measure of disease progression for AD-related pathophysiological changes.