扩散张量成像对糖尿病患者肾脏功能的研究

Diffusion tensor imaging for the assessment of renal function of diabetes mellitus

目的探讨磁共振扩散张量成像(DTI)在评价糖尿病患者肾脏功能方面的应用价值。方法分别对20例糖尿病患者和20例健康志愿者进行3.0T磁共振肾脏DTI扫描,采用独立样本t检验分别比较两组皮质、髓质各向异性分数(fractional anisotropy,FA)和表观扩散系数(apparent diffusion coefficient,ADC),并进行肾脏扩散张量纤维束成像(DTT)。结果糖尿病患者髓质FA值、ADC值(0.428±0.015、2.074±0.127×10^(-3)mm^2/s)均低于健康志愿者(0.454±0.027、2.194±0.177×10^(-3)mm^2/s),差异有统计学意义(P<0.05),髓质FA值差异较显著;糖尿病患者皮质FA值、ADC值(0.243±0.011、2.381±0.164×10^(-3)mm^2/s)均低于健康志愿者FA、ADC值(0.253±0.020、2.423±0.195×10^(-3)mm^2/s),差异无统计学意义(P>0.05)。扩散张量纤维束成像(DTT)可以显示肾小管、直小血管等纤维束样结构呈放射状指向肾盂,糖尿病患者的纤维束样结构略稀疏。结论扩散张量成像可早期定量评价糖尿病患者的肾脏功能,有利于糖尿病患者的早期预防和治疗。

Objective To investigate the value of renal function in diabetes mellitus using magnetic resonance（ MR） diffusion tensor imaging（ DTI）. Methods DTI data and diffusion tensor tractography（ DTT） for twenty diabetes mellitus and twenty healthy volunteers were collected using 3. 0T MR system. Within the groups,mean fractional anisotropy（ FA） and mean apparent diffusion coefficient（ ADC） values in the renal cortex and medulla were calculated separately. The difference was evaluated using the independent sample t-test. Results Mean FA and ADC values of renal medulla were significantly lower in diabetes mellitus（ 0. 428 ± 0. 015,2. 074 ± 0. 127 × 10^-3mm^2/ s） compared with healthy volunteers（ 0. 454 ± 0. 027,2. 194 ± 0. 177 × 10^-3mm^2/s）（ P . 05 and P . 05,respectively）. Mean FA and ADC values of renal cortex between diabetes mellitus（ 0. 243 ± 0. 011,2. 381 ± 0. 164 × 10^-3mm^2/ s） and healthy volunteers（ 0. 253 ± 0. 020,2. 423 ± 0. 195 × 10^-3mm^2/ s） did not show significant differences（ P 〉. 05）. Tractography images illustrated the preferred diffusion direction along the tubules and the vessels radial to the renal pelvis. Tractography visualized the reduced radial diffusion tracts in diabetes mellitus. Conclusion DTI can investigate the renal function of diabetes mellitus before diabetic nephropathy quantitatively. It is helpful for early prevention and treatment.