Kidney size and its correlation with demographics: a retrospective CT Scan-based study from Pakistan

Abstract Background Kidney size is a critical parameter in the assessment of renal health, yet population-specific reference values are lacking for Pakistan. This study aimed to establish normative computed tomography (CT)-based renal dimensions and volumes in a healthy Pakistani cohort and to explore their correlations with demographic and functional parameters. Results A total of 96 healthy adults were included, with a mean age of 36.8 ± 9.8 years. The mean renal length was 103.4 ± 7.2 mm on the right and 104.7 ± 7.4 mm on the left. The mean parenchymal thickness measured 13.1 ± 2.1 mm (right) and 12.7 ± 2.1 mm (left), while the corresponding full kidney thickness measured 49.7 ± 7.0 mm and 48.8 ± 8.2 mm, respectively. Mean kidney volumes were 125.6 ± 31.4 mL (right) and 134.7 ± 34.2 mL (left). Men had significantly larger kidneys than women across all dimensions, including volume. Renal size showed significant positive correlations with height, weight and body mass index. Kidney volume increased significantly across body mass index categories (ANOVA p = 0.002). Age demonstrated only minimal correlation with renal dimensions. Importantly, kidney volume and parenchymal thickness were significantly correlated with creatinine clearance (r = 0.29–0.30, p = 0.003 and r = 0.38, p < 0.001, respectively). Conclusions This study provides the first CT-based reference ranges for kidney size and volume in a healthy Pakistani population. Renal dimensions are strongly influenced by gender and body habitus, while kidney volume and parenchymal thickness appear to be more functionally relevant than renal length. These population-specific norms will aid radiologists and nephrologists in donor evaluation, clinical decision-making, and early detection of renal pathology.