Renal Ultrasound Findings and Estimated Glomerular Filtration Rate (eGFR): A Cross-Sectional Observational Study

Background: Ultrasound (US) imaging is widely used in Nephrology for the non-invasive assessment of renal morphology and perfusion. This study investigates correlations between sonographic parameters and renal function measured as estimated glomerular filtration rate (eGFR). Methods: This single-center prospective cross-sectional study enrolled 130 patients undergoing renal ultrasound. Parameters included renal length, parenchymal thickness, cortical–medullary differentiation, renal volume, and intrarenal resistive index (IR). eGFR was calculated using the CKD-EPI formula. Statistical analysis assessed correlations and developed a multivariable predictive model. Results: Renal length and parenchymal thickness correlated positively with eGFR (r = 0.381 and 0.364, p < 0.001), while IR correlated negatively (r = −0.549, p < 0.001). Multivariate regression identified sex, renal length, IR, cortical–medullary differentiation, and solitary/shrunken kidney as significant predictors of eGFR. The final model showed a predictive correlation coefficient of r = 0.6632. Specific ultrasound parameters, particularly renal length and IR, show significant correlation with eGFR. Conclusions: A predictive model incorporating these factors may assist in estimating renal function non-invasively.