Evaluation of early renal function changes in patients with type 2 diabetes mellitus using BOLD and ASL / 中华放射学杂志

ABSTRACT

Objective:To noninvasively evaluate the clinical value of early renal function changes in patients with type 2 diabetes mellitus (T2DM) using blood oxygenation level dependent (BOLD) and arterial spin labeling (ASL) MRI.Methods:A total of 63 T2DM patients from Tianjin First Central Hospital from September 2019 to May 2022 were prospectively collected, 30 healthy volunteers (control group) were collected during the same period. According to albumin creatinine ratio (ACR), patients with T2DM were divided into normal albuminuria (NAU, ACR<30 mg/g) group and microalbuminuria (MAU, 30 mg/g≤ACR≤300 mg/g) group, there were 35 and 28 cases respectively. All subjects underwent abdominal BOLD and ASL scans. The values of renal cortical and medullary apparent relaxation rate (R 2*) and renal cortical renal blood flow (RBF) were measured. One-way ANOVA was used to compare the differences in R 2* and RBF among the three groups. Receiver operating characteristic curve was used to analyze relevant parameters to identify the diagnostic effectiveness of each group, and area under the curve (AUC) was compared by Z-test. Results:There were significant differences in renal medullary R 2* and renal cortical RBF among the control group, NAU group and MAU group ( F=45.83, 34.15, P<0.001). There was no significant difference in renal cortical R 2* ( F=2.98, P=0.056). In differentiating the control group from the NAU group, the AUC of renal medullary R 2*, renal cortical RBF and their combined parameters were 0.921 (95%CI 0.827-0.973), 0.704 (95%CI 0.578-0.811), 0.964 (95%CI 0.885-0.994), respectively. The AUC of combined parameters was significantly different from renal cortical RBF ( Z=4.07, P<0.001), but not from renal medullary R 2* ( Z=1.57, P=0.117). In differentiating the NAU from the MAU group, the AUC were 0.898 (95%CI 0.796-0.960), 0.919 (95%CI 0.823-0.973), 0.985 (95%CI 0.881-0.994), respectively. The AUC of combined parameters was significantly different from renal medullary R 2* and renal cortical RBF ( Z=2.39, P=0.017; Z=2.20, P=0.028). Conclusions:The changes of renal oxygenation level and blood flow in early stage of T2DM patients can be evaluated noninvasively and quantitatively using BOLD and ASL. Renal medullary R 2* combined with renal cortex RBF shows better diagnostic efficacy for early renal function changes in diabetes than each single index.