Calculating eGFR Using Apparent Diffusion Coefficient (ADC) Values Obtained Through MR Imaging

[Background]Renal dysfunction is associated with significantly lower apparent diffusion coefficient (ADC) values. There are several ADC-level cutoff points that indicate renal dysfunction.[Objectives]This study aimed to evaluate whether or not ADC values can predict estimated glomerular filtration rate (eGFR) levels. If so, the formula to calculate eGFR level by ADC levels will be formulated.[Patients and Methods]We reviewed all adult patients who underwent upper abdomen MRI and magnetic resonance cholangiopancreatography (MRCP) protocol from January 2014 to October 2014. The ADC values and eGFR levels were recorded. The multivariate linear regression was implemented between the eGFR and studied variables. The formula to predict eGFR was produced by the final model of multivariate linear regression analysis. An online formula for eGFR prediction was also created.[Results]There were 261 patients who met the study criteria of which 133 patients were male (51.10). The mean age and body weight (S.D.) of all patients was 59.89 years (13.73) and 55.92 kg (11.17), respectively. The majority of patients had an eGFR of 60 - 89 mL/min (107 patients; 41.00%). The average ADC value of all patients was 1.87 × 10^-3 mm²/s. There were four factors that were significantly associated with eGFR by multivariate linear regression analysis: age, sex, body weight, and ADC value. ADC value had the highest estimates at 121.94.[Conclusion]ADC values can predict eGFR using the following formula: estimated eGFR = -139.03 - (0.80 × age) - (4.19 × sex; [0 if female and 1 if male]) + 0.57 (body weight in kg) + (121.94 × ADC). This formula was also created as an online tool for both mobile and computer at http://202.28.94.20/gfr/.