Determination of Renal Volume using Ultrasonography and its Correlation with Renal Function: A Cross-sectional Study

Abstract

Introduction: Renal length and volume are important indicators for the presence or progression of disease in urology and nephrology. Estimation of renal volume by Ultrasonography (USG) has clinical utility for the physician, nephrologist, and urologist. Aim: To measure individual renal volume by ultrasonography and determine its relationship with renal function as measured by the Diethylene Triamine Penta-acetic Acid (DTPA) in normal adults. Materials and Methods: It was a cross-sectional study conducted on fifty patients who underwent DTPA scans both in Outpatient (OPD) and In-Patient Department in the Department of Urology, of a tertiary care centre from January 2020 to December 2020. All the transplant donors who underwent donor nephrectomy were included in the study. A sonographic assessment was done and the Glomerular Filtration Rate (GFR) was calculated by Technetium (Tc)-154 DTPA. The primary outcome was to determine the relationship between renal volume with renal function in normal adults. The secondary outcome was to measure individual renal parameters sonographically. They were assessed for correlation between renal parameters (mainly renal volume) and DTPA using Pearson’s coefficient. Results: The age range of the subjects was 18-70 years. GFR calculated by DTPA for the right kidney had a better correlation with renal volume (r=0.241) on the right and 0.162 on the left, both with a p-value of 0.001). GFR of the left kidney had a better correlation with left kidney volume (r=0.184) than right kidney volume (r=0.130). No correlation was found between GFR with renal Anteroposterior (AP) dimension, renal width, and renal length. The kidney volume was more significant on the left-side (r=0.351) than on the right kidney (r=0.263). Conclusion: Renal volume correlated well with renal function. Sonographic assessment of renal volume rather than renal length would serve as a tool to evaluate renal status for evaluation and follow-up.