Assessment of total kidney volume by computed tomography in autosomal dominant polycystic kidney disease and its correlation with estimated glomerular filtration rate

Background: Autosomal dominant polycystic kidney disease (ADPKD) is characterised by progressive renal cyst enlargement, leading to increased total kidney volume (TKV), declining kidney function, and eventual end-stage renal disease. Aims and Objectives: This study aimed to estimate TKV using computed tomography (CT) and assess its correlation with the estimated glomerular filtration rate (eGFR) as a structural marker of disease progression. Materials and Methods: This prospective study included 25 patients with ADPKD aged 15–46 years who had preserved renal function. The TKV was measured using contrast-enhanced CT through freehand manual planimetry. Renal function was assessed using serum urea, creatinine, and eGFR (Chronic Kidney Disease Epidemiology Collaboration) at baseline and 12-month follow-up. The association between TKV and eGFR changes was analysed using Pearson’s correlation and linear regression. Results: At baseline, the mean eGFR was 90.72 mL/min/1.73 m2, which significantly decreased to 81.52 mL/min/1.73 m2 after 1 year (P=0.001). The TKV increased significantly from 847.6 mL at baseline to 933.84 mL at 1 year (P=0.001). A moderate positive correlation was observed between the percentage increase in TKV and the percentage reduction in eGFR (r=0.53). Linear regression analysis demonstrated that for each 1% increase in TKV, there was a corresponding 0.89% increase in the percentage reduction in eGFR (β=0.893, 95% Confidence interval: 0.27–1.52, P=0.007). Conclusion: This study demonstrates a significant association between increasing TKV and decreasing renal function in ADPKD, supporting the use of TKV as a marker of disease progression. CT-based volumetric assessment may aid in the early identification of patients at risk of rapid functional deterioration.