早期糖尿病肾病大鼠模型磁共振弥散加权成像的初步研究

目的:探讨早期糖尿病肾病(Diabetic nephropathy,DN)模型大鼠磁共振弥散加权成像(Diffusion Weight Imaging,DWI)肾实质ADC值变化规律。方法:将20只清洁级雄性SD大鼠随机分成两组,糖尿病肾病组(DN组)12只,正常对照组(NC组)8只;DN组给予60 mg/kg链尿佐菌素腹腔注射诱导糖尿病肾病模型,NC组按照相同方法、相同剂量柠檬酸缓冲液腹腔注射;并对最终糖尿病模型造模成功并且存活的8只DN大鼠、8只NC大鼠进行MRI扫描,包括常规轴位T1WI、T2WI扫描及DWI扫描;扫描结束后收集血液送血肌酐及双肾组织进行病理检查。并测量每只大鼠双肾皮、髓质的ADC值。结果:造模后,DN组大鼠血糖明显升高、尿量明显增加、体重明显减低,DN组大鼠肾脏出现不同程度病理损伤,符合早期DN病理改变。DN组大鼠肾脏皮、髓质ADC值分别为1.522±0.913×10^-3 mm^2/s、1.268±0.388×10^-3 mm^2/s,较NC组肾脏皮、髓质ADC值1.276±0.341×10^-3 mm^2/s、1.011±0.217×10^-3 mm^2/s增高,两组比较有统计学意义(P<0.05)。结论:DWI成像ADC值可能反映早期糖尿病肾病肾脏功能的变化。

A Preliminary Study of Diffusion-weighted Magnetic Resonance Imaging in Early Diabetic Nephropathy Rats

Objective:To investigate the changes of ADC value in renal parenchyma of early diabetic nephropathy(DN)using diffusion weighted magnetic resonance imaging(DWI).Methods:20 healthy male SD rats were randomly divided into diabetic group of 12 rats(DN group)and normal control of 8 rats(NC group).We injected intraperitoneally 60 mg/kg streptozotocin in DN group to establish the model of diabetic nephropathy.The NC group was injected the same dose of citrate buffer in the same way.Finally,there were eight DN rats which modeled Successfully and surviving and eight NC rats underwent MR scan.The scan sequences include axial T2WI,T1WI and DTI sequence.At the end of the scan,we killed all rats immediately,and collected the blood sample to exam the serum creatinine and double kidney tissues for pathological examination.The ADC value of renal parenchyma in each rat were measured.Results:After modeling,the blood glucose,urine volume and body weight in DN group were significantly increased,and there was significant difference between the two groups.The pathological changes of kidney in DN group were consistent with the pathological changes of early DN.The ADC values of renal cortex(1.522±0.913×10^-3 mm^2/s)and medulla(1.268±0.388×10^-3 mm^2/s)in DN group were higher than those of in NC group(1.276±0.341×10^-3 mm^2/s,1.011±0.217×10^-3 mm^2/s),and there was statistical significance between the two groups.Conclusions:The ADC value of DWI can reflect the changes of renal function in early stage of diabetic nephropathy.