Variability of Renal ADC: Limitations of Monoexponential Model

Jeff Lei Zhang¹, Eric E. Sigmund¹, Henry Rusinek¹, Hersh Chandarana¹, Qun Chen¹, Pippa Storey¹, Louisa Bokacheva¹, Vivian S. Lee¹

Previously reported values of ADC in healthy kidneys vary considerably. In this study, high quality volunteer data were acquired and were fitted by mono-exponential model. Fitting the data at 19 sets of b values used in literature resulted in predicted ADC values from 2.1x10^-3 to 3.110^-3 mm²/s. Significant correlation was found between the predicted and the reported values for cortex (R² = 0.50) and medulla (R² = 0.28). This indicates that the substantial variability among reported values in the literature is due to the application of monoexponential model to renal diffusion data that reflect substantial vascular and tubular flow effects.