Developmental variation of renal apparent diffusion coefficient in rat / 中华放射学杂志

ABSTRACT

Objective To analyze the changes of renal apparent diffusion coefficient(ADC)value during development in intact rats.Methods Five intact male Wistar rats(1 month of age)were involved in this study.Using SE-echo planar imaging(EPI)sequence to acquire renal DWI at a 3.0 T MR on day 1,day 5,day 10,day 30,and day 50,respectively.The b value was 0 and 500 s/mm2.The ADCs of the cortex and the medulla were measured on the right kidney and the renal volume was calculated by manually renal outling on each slice.The difference of ADC between the cortex and the medulla was analyzed using a paired student t test,and the changes of renal volume and ADCs with rats development were evaluated with a repeated measurement ANOVA.Results The ADC of the cortex was higher than that of the medulla except on day 1(P＜0.01).when b value 0 and 500 s/mm2 were chosen.Renal volume increased with the rat development.from(0.86±0.02)ml to(1.47±0.21)ml.And the ADCs of both the cortex and medulla increased from(1.66±0.14)×10-3mm2/s to(1.96±0.08)×10-3mm2/s for the cortex and from (1.54±0.12)×10-3mm2/s to(1.91±0.09)×10-3mm2/s for the medulla.Conclusion Renal ADCs of both the cortex and medulla increase during the period from 1 to about 3 months of age in rats.The influence of age on renal ADC should be considered when choosing rats aged from 1 to 3 months for MR study.