Published online Aug 28, 2018. doi: 10.4329/wjr.v10.i8.83
Peer-review started: May 4, 2018
First decision: June 6, 2018
Revised: June 26, 2018
Accepted: July 10, 2018
Article in press: July 10, 2018
Published online: August 28, 2018
Processing time: 117 Days and 20.2 Hours
To investigate the utility of renal diffusion tensor imaging (DTI) to detect early renal damage in patients with type 2 diabetes.
Twenty-six diabetic patients (12 with microalbuminuria (MAU), and 14 with normoalbuminuria) and fourteen healthy volunteers were prospectively included in this study. Renal DTI on 3.0 T MR was performed, and estimated glomerular filtration rate (eGFR) was recorded for each subject. Mean cortical and medullary fractional anisotropy (FA) values were calculated by placing multiple representative regions of interest. Mean FA values were statistically compared among groups. Correlations between FA values and eGFR were evaluated.
Both cortical and medullary FA were significantly reduced in diabetic patients compared to healthy controls (0.403 ± 0.064 vs 0.463 ± 0.047, P = 0.004, and 0.556 ± 0.084 vs 0.645 ± 0.076, P = 0.002, respectively). Cortical FA was significantly lower in diabetic patients with NAU than healthy controls (0.412 ± 0.068 vs 0.463 ± 0.047, P = 0.02). Medullary FA in diabetic patients with NAU and healthy controls were similar (0.582 ± 0.096 vs 0.645 ± 0.076, P = 0.06). Both cortical FA and medullary FA correlated with eGFR (r = 0.382, P = 0.015 and r = 0.552, P = 0.000, respectively).
FA of renal parenchyma on DTI might serve as a more sensitive biomarker of early diabetic nephropathy than MAU.
Core tip: Early diagnosis of diabetic nephropathy (DN) facilitates timely treatment, and therefore, improves patient outcomes. Microalbuminuria (MAU), a standard biomarker of DN, has limited sensitivity and reproducibility. Diffusion tensor imaging (DTI) quantifies the directional nature of water diffusion and is especially suited for highly oriented organs such as the kidney. DTI parameter changes were reported in several renal pathologic conditions. This study exhibited reductions of renal fractional anisotropy (FA) in diabetic patients, even with normoalbuminuria, which raises the possibility of detecting early DN with higher sensitivity than MAU. Furthermore, renal FA demonstrated statistical correlation with eGFR, making it a potential functional biomarker.