BOLD MRI评价糖尿病患者尿微量白蛋白及氧合水平的研究

目的 利用血氧水平依赖磁共振成像(blood oxygenation level dependent magnetic resonance imaging,BOLD MRI)技术探讨2型糖尿病患者不同尿微量白蛋白与肌酐比值(the ratio of urinary albumin and creatinine,ACR)与肾脏氧合状态的关系。方法 对44例2型糖尿病患者及14例健康志愿者(对照组)行肾脏BOLD MRI检查,糖尿病患者根据ACR分为ACR正常糖尿病组(22例)、早期糖尿病肾病组(10例)、临床糖尿病肾病组(12例),分别测量肾脏皮质、髓质的表观自旋-自旋弛豫率(apparent relaxation rate,R2^*)值并进行组间比较及分析其与临床指标的相关性。结果 相比正常对照组,ACR正常糖尿病组(P=0.015)、临床糖尿病肾病组(P=0.023)的肾脏髓质R2^*值明显增加,差异有统计学意义;早期糖尿病肾病组较对照组的肾脏髓质R2^*值升高,但差异无统计学意义;糖尿病各组较对照组的肾脏皮质R2^*值升高,但差异无统计学意义。ACR与髓质R2^*值呈正相关(r=0.409,P=0.006)。结论 BOLD MRI可无创评估糖尿病患者ACR不同阶段的肾脏氧合水平,监测糖尿病患者早期肾髓质功能性缺氧改变。

Assessment of urinary microalbumin and oxygenation in diabetic patients using blood oxygenation level-dependent MRI

Objective To explore the relationship between the ratio of urine albumin to creatinine(ACR) and renal oxygenation in patients with type 2 diabetes by blood oxygen level-dependent magnetic resonance imaging(BOLD MRI). Methods Totally 44 patients with type 2 diabetes and 14 healthy volunteers were recruited. Diabetic patients were divided into ACR normal diabetic group, early diabetic nephropathy group and clinical diabetic nephropathy group based on ACR. Bilateral renal cortical R2^*(CR2^*) and medullary R2^*(MR2^*) values were extracted and quantified on BOLD MRI. CR2^* and MR2^* were compared among the groups separately. The relationships were analyzed between R2^* values and clinical index of renal function. Results Compared with controls, MR2^* in ACR normal diabetic group(P=0.015) and clinical diabetic nephropathy group(P=0.023) were significantly increased. MR2^* in the early diabetic nephropathy group was higher than that in normal control group, but the difference was not statistically significant. CR2^* in each diabetes group was higher than that in the normal control group, but there was no statistical difference. The positive correlation was found between MR2^* and ACR(r=0.409, P=0.006). Conclusion BOLD MRI could non-invasively evaluate the renal oxygenation level in different stages of ACR in diabetic patients and monitor functional hypoxia changes in renal medulla in early diabetic patients.