慢性肾病早期肾间质纤维化磁共振功能成像的初步研究

Functional Evaluation of Early Renal Interstitial Fibrosis in Patients with Chronic Kidney Disease Using Diffusion-Weighted and BOLD MR Imaging: Preliminary Experience

摘要: 目的：探讨MR DWI和BOLD应用于临床评价慢性肾病患者早期肾间质纤维化功能改变的价值。方法：收集了26例经肾穿刺活检证实为早期肾间质纤维化的慢性肾脏患者，男12例，女14例，平均年龄38.7岁(16~71岁)；26例健康自愿者为对照组，其年龄、性别与病例组匹配。采用GE 3.0T磁共振仪行T1WI、T2WI、DWI (b = 600 s/mm2)及BOLD扫描成像。利用工作站Fuctool软件对所有DWI和BOLD图像进行后处理，由两名有经验的主治医师对研究对象肾实质兴趣区的ADC值和R2*值进行测量和统计分析。结果：病例组26例早期肾间质纤维化的慢性肾病患者中15.4%(4/26)血清肌酐、尿素升高；84.6%(22/26)尿微量蛋白定量升高；病例组左、右肾实质ADC值较对照组减小(P < 0.01)；病例组左、右肾皮、髓质的R2*较对照组增高(P < 0.05)；病例组双肾实质的ADC值与髓质R2*值无相关性(P > 0.05)。结论：慢性肾病早期肾间质纤维化阶段存在肾组织水分子运动及肾组织血氧饱和度及氧含量的变化；早期肾间质纤维化肾实质ADC值有降低趋势，而R2*值有增加趋势；两者联合应用可以在肾间质纤维化早期诊断及疗效评价方面发挥作用。 Objective: To investigate the clinical value of DWI and BOLD MRI in evaluating functional changes of early renal interstitial fibrosis in patients with chronic kidney disease (CKD). Methods: Study protocol was approved by the local ethics committee. A group of 26 patients with renal biopsy confirmed CKD were studied (12 males and 14 females; aged 16 - 71 years, with a mean age of 38 years) and 26 age- and sex-matched healthy volunteers served as control group. T1WI, T2WI, DW and BOLD MR imaging were detected with a GE 3.0T MRI scanner. Post-processing of all ADC and R2* maps of kidney with Fuctool software was done in a workstation. ADC and R2* values of interested regions in the renal parenchyma were measured and analyzed by two experienced doctors. Results: Among study group, 4 patients (15.4%) had serum creatinine and urea elevated, and 22 (84.6%) had microalbuminuria detected. The ADC values of left and right renal parenchyma were significantly lower (P < 0.01) and the R2* values of renal cortex and medulla were significantly higher (P < 0.05) in CKD group than those of the control group. No correlation between the ADC values of renal parenchyma and R2* values of medulla in the study group was found (P > 0.05). Conclusion: Motion of water molecules and changes of blood oxygen saturation and content exist in renal tissues at the early stage of renal interstitial fibrosis. The ADC values of renal parenchyma tend to decrease whereas R2* values tend to increase at the early stage of renal interstitial fibrosis. Taking the ADC and R2* together has a great value in early diagnosis and therapeutic efficacy evaluation.