Noninvasive evaluation of diabetic patients with high fasting blood glucose using DWI and BOLD MRI

To investigate the renal microstructure changes and hypoxia changes in type 2 diabetic patients and the relationship between them and glucose using both diffusion-weighted imaging (DWI) and blood oxygenation level-dependent magnetic resonance imaging (BOLD MRI).

After measuring morning fasting blood glucose, DWI and BOLD MRI were performed in 57 patients with type 2 diabetes mellitus (DM group) and 14 healthy volunteers (NC group). According to the fasting blood glucose levels, diabetic patients were divided into a normoglycemic diabetes group (group A), a less hyperglycemic diabetes group (group B) and a more hyperglycemic diabetes group (group C). The renal parenchymal apparent diffusion coefficient (ADC), renal cortical R2* (CR2*), and medullary R2* (MR2*) were measured, and the R2* ratio between the medulla and cortex (MCR) was calculated. To test for differences in ADC, R2*, and MCR among the four groups, the data were analyzed by separate one-way ANOVAs. The correlations between ADC, R2*, and MCR and the clinical index of renal function were analyzed.

Groups B and C had significantly lower ADC values in the renal parenchyma (P = 0.048, 0.002) and significantly higher MR2* and MCR values (P < 0.000, P = 0.001, 0.001, and 0.005, respectively) than the NC group. ADC was negatively correlated with glucose, and MR2*, MCR and glucose showed a weak positive correlation.

DWI and BOLD may indirectly and qualitatively reflect the kidney microstructure status and hypoxia level of diabetic patients at different blood glucose levels to a certain extent, and possibly guide the clinical treatment of diabetic patients with different blood glucose levels.