DWI和1H-MRS在肝纤维化中的诊断价值

目的:探讨扩散加权成像(DWI)与氢质子波谱分析(1H-MRS)在肝纤维化中的诊断价值.方法:使用腹腔注射CCl4溶液法诱导建立兔肝纤维化模型并进行DWI和1 H-MRS检查.DWI使用SE-EPI序列(b1 =0 s/mm2,b2=600 s/mm2),1H-MRS使用单体素点分辨波谱分析(PRESS)序列(TR 1500 ms,TE 35 ms),测量表观扩散系数(ADC)值及胆碱(Cho)和脂质(lipid)波峰下面积的比值(Cho/lipid).以病理学肝纤维化分期为基础,将兔划分为无肝纤维化组(S0)、轻度-中度纤维化组(S1-S2)和重度纤维化及肝硬化组(S3 -S4),比较不同组间ADC值和Cho/lipid变化规律.结果:随肝纤维化程度加重,ADC值依次降低(P＜0.01),Cho/lipid依次升高(P＜0.05);重度纤维化及肝硬化组与另两组ADC值及Cho/lipid差异均具有统计学意义(P均＜0.05).结论:DWI和1H-MRS具备一定的定量肝纤维化及检测重度纤维化及肝硬化的能力.

Diffusion-weighted imaging and proton MR spectroscopy used in the diagnosis of liver fibrosis in rabbits

Objective:To investigate the value of diffusion-weighted imaging(DWI) and proton MR spectroscopy(1H-MRS) in the diagnosis of liver fibrosis in rabbits.Methods:Rabbits with liver fibrosis induced with CCl4 and controls underwent DWI and 1H-MRS.Diffusion-weighted SE EPI single shot sequence(b1=0s/mm2,b2=600s/mm2) and 1H-MRS PRESS technique(TR 1500ms,TE 35ms) were used to measure apparent diffusion coefficient(ADC) values and choline-to-lipid ratios(Cho/lipid).Rabbits were divided into groups of no fibrosis(stage 0),mild/moderate fibrosis(stage Ⅰ and Ⅱ) and severe fibrosis/cirrhosis(stage Ⅲ and Ⅳ) based on histological examinations from resected liver.The mean ADC value and Cho/lipid among different groups of liver fibrosis were compared.Results:The mean ADC value decreased as the severity of liver fibrosis increased(P<0.01),while the mean Cho/lipid increased as the severity of liver fibrosis progressed(P<0.05).Both the mean ADC value and the Cho/lipid were statistically different between severe fibrosis/cirrhosis and the other groups of fibrosis(P<0.05).Conclusion:The preliminary experimental results demonstrate the potential usefulness of DWI and 1H-MRS for diagnosis and quantification of liver fibrosis.