多b值扩散加权成像双指数模型对HIV早期感染诊断的应用价值研究

Differential diagnosis of AIDS: study of multi b-value DWI double-exponential model

目的探讨多b值扩散加权成像单指数模型与双指数模型对于HIV阳性诊断的作用。材料与方法对23名青少年(15例HIV阳性,8例HIV阴性)进行脑部多b值弥散加权成像(diffusion weighted imaging,DWI)检查,b值分别为0、50、150、200、400、600、800 s/mm2。对图像信号数据分别进行单指数模型和双指数模型拟合,得出额上回的表观扩散系数(apparent diffusion coefficient,ADC)、快弥散系数(fast apparent diffusion coefficient,ADCf)、慢弥散系数(slow apparent diffusion coefficient,ADCs)、以及慢弥散系数所占比例(As)并进行统计学分析。结果感染人类免疫缺陷病毒(human immunodeficiency virus,HIV)患者左侧额叶的ADCf值(4.609±3.254)较健康对照组ADCf值(8.871±5.040)有显著性差异(P<0.05),两组右侧额叶ADCf值显著性差异(P>0.05)。两组的ADCs、ADC均无显著性差异(P>0.05)。结论多b值扩散加权成像中的ADCf值能够为获得性免疫缺陷综合征(acquired immunodeficiency syndrome,AIDS)诊断提供一定参考价值。

Objective： To discuss how mono-exponential model and doubleexponential model of multi-b value diffusion weighted imaging perform in HIV diagnosis. Materials and Methods： Multi-b value DWI（b=0, 50, 150, 200400, 600,800） was performed to 23 teenagers, 15 of whom were HIV-positive and 8 of whom were HIV-negative. By fitting the images of mono-exponential model and doubleexponential model, ADCs, ADCf, ADC values in frontal lobe were compared between HIV-positive subjects and HIV-negative subjects by statistical analysis. Results： For left frontal lobe, HIV-positive subjects have significantly lower ADCf values than HIV-negative subjects. While ADCs, ADC values are not significantly different.Conclusion： Double-exponential model of multi-b value diffusion weighted imaging,especially ADCf values can be a reference in AIDS diagnosis.