414-P: Apparent Diffusion Coefficient on Diffusion-Weighted Magnetic Resonance Imaging Predicts the Progression of Renal Damage in Diabetic Nephropathy

Abstract

Renal damage in diabetic nephropathy (DN) is evaluated by biochemical tests such as urine albumin-to-creatinine ratio (UACR) and serum estimated glomerular filtration rate (eGFR). On the other hand, renal biopsy, which is rich in definitive information, is rarely performed because of its complexity and high invasion. To evaluate whether diffusion-weighted magnetic resonance imaging (DW-MRI) could be a noninvasive approach for distinguishing DN, we performed MRI scanning of the subjects with 6 b-values (b = 0, 50, 100, 350, 400, 700) and analyzed the parameters using the kidney imaging software (Hitachi, Ltd., Tokyo). A total of 40 subjects were enrolled, 25 of whom had type 2 diabetes with or without hypertension (T2D), 9 had nondiabetes but hypertension (HT), and 6 were healthy volunteers (Control). T2D showed lower values of apparent diffusion coefficient (ADC) 0-700 compared with HT (129.0 ± 2.12 x10-5mm2/s in T2D vs. 132.5 ± 1.43 ×10-5mm2/s in HT, p<0.001). In addition, T2D with HT (n=15) had lower ADC0-700 compared with T2D without HT (n=10) (p < 0.01). Interestingly, T2D with non-DN nor HT presented lower ADC0-700 compared with HT (p<0.05). ADC0-700 in T2D were correlated with serum eGFR (r = 0.40, p <0.05) and inversely correlated with serum creatinine (r = - 0.40, p <0.05), cystatin C (r = - 0.54, p <0.01) and UACR (r = - 0.57, p <0.01). On the other hand, ADC0-700 in HT were not correlated with any of parameters of the renal function. Multivariate regression analysis with a stepwise forward method identified UACR as the only factor associated with the ADC0-700 values (β = - 0.68, p <0.001). Accumulating evidences show that lower levels of ADC on DW-MRI indicate greater fibrosis in various organs. Therefore, cortical ADC0-700 could predict the progression of the renal damage such as tubulointerstitial fibrosis. DW-MRI might provide a convenient diagnostic tool in the evaluation of DN. Disclosure H. Kitsunai: None. Y. Takiyama: Other Relationship; Self; Gilead Sciences, Inc., Research Support; Self; Boehringer Ingelheim Pharmaceuticals, Inc., Mochida Pharmaceutical Co., Ltd., Roche Diabetes Care, Taisho Pharmaceutical Co., Ltd. N. Nakagawa: None. N. Hasebe: None. A. Okizaki: Research Support; Self; Fuji-Film Toyama Chemical Co., Ltd., Nihon Medhi-physics. M. Haneda: Advisory Panel; Self; Eli Lilly Japan K. K., Nippon Boehringer Ingelheim Co. Ltd., Novo Nordisk Inc. Funding Japan Society for the Promotion of Science (20K17420)