Currently available clinical indicators of kidney disease lack the sensitivity or specificity to identify early-stage diabetic nephropathy (DN).1 Quantitative diffusion magnetic resonance imaging (MRI), specifically Intravoxel Incoherent Motion (IVIM) and diffusion tensor imaging (DTI), has been used to quantify pathophysiologic changes in other organs but has not been well studied in kidney diseases, including DN. It was proved that ADC value of IVIM was more sensitive than the one in DTI to the renal tumor diagnosis. The goal of this pilot study was to assess the ADC value in kidney of IVIM and DTI in distinguishing diabetic subjects versus healthy controls.Four patients with type 2 diabetes (mean age 45.0±3.6 years) and 11 healthy controls (mean age mean age 24.1±6.7 years) were recruited for this study. All four patients with chronic kidney disease due to diabetic nephropathy manifested increasing 24 hours proteinuria. All MR examinations in this study were performed by a clinical 3.0T MR scanner (Ingenia, Philips Healthcare, Best, the Netherlands). For IVIM MRI, echo-planar imaging (EPI) sequence were acquired with 11 b values (0, 10, 20, 40, 60, 100, 150, 200, 300, 500, and 700 s/mm2), voxel size of 0.9´0.9´4.0 mm3, TE/TR of 52/500ms, SENSE=2, direction=3. To separate the perfusion and diffusion, a bi-exponential fitting was used to calculate the perfusion fraction (f), pseudo-diffusion coefficient (D*) and D on Philips Research Integrated Development Environment (PRIDE) software written in Interactive Data Language. DTI was acquired with an oblique-coronal fat-saturated imaging sequence with the following parameters: 6 diffusion directions; b values, 0 and 300 s/mm2; TR/TE, 405/43ms; 2 averages; 9 slices; 4 mm slice thickness with no intersection gap; field of view, 230× 230 mm2; matrix, 128 × 128; SENSE=2. To obtain IVIM and DTI parameters, 3 regions of interest (ROIs) were placed in each cortex and medulla of the kidney by an experienced abdominal radiologist. A total of 6 ROIs were analyzed for each person and each ROI was set to contain 5 pixels. These parameters of renal cortex and renal medulla were compared within each group using the t-test using SPSS 19.0 software (SPSS Inc., Chicago, IL, USA). A p<0.05 was considered statistically significant.All examinations were diagnostic, and no considerable artifacts due to misregistration or distortion were observed. Table 1 summarizes data from IVIM and DTI analysis for all healthy controls and patients with diabetes nephropathy in this study. Cortical ADC and D of patients with DN were significantly lower than those of healthy controls (P < 0.01, P<0.001). Average D* showed a high intra-individual and inter-individual variance and did not demonstrate significant difference between two groups. The reduction of D values in the cortex and medulla was more obvious than ADC in patients. IVIM distinguishes pseudo-diffusion (tubular=vascular flow) from passive structural diffusion by collecting data over a range of diffusion weightings.2 It was proved that ADC value of IVIM was more sensitive than the one in DTI to the renal tumor diagnosis. 3In contrast to previous studies, however, the current study utilized IVIM and DTI techniques and specifically focused on diabetics. With a limited number of subjects in the current pilot study, our findings suggested that both cortical ADC and D might identify changes in diabetics and the D values seemed to be more sensitive, which could indicate early DN. Longitudinal studies with more diabetic subjects are necessary to confirm this hypothesis in near future.The results of this pilot study suggested that cortical D and ADC, quantified by kidney IVIM and DTI could be potential imaging biomarkers for DN. IVIM could reflect the renal function more sensitive and accurate in DN patients.