Renal Volume Nomogram on Computed Tomography in North Indian Population Correlated with Age, Gender and Height

Abstract

Introduction: Assessment of renal size is a difficult task in view of the complex shape of kidney. Among different imaging modalities Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) owing to their 3 Dimensional reconstructional ability are quite helpful in assessment of kidney size. A relationship between renal size and anthropometric parameters is an issue of interest. Aim: To assess kidney size in North Indian adult population using CT and to assess its relationship with age, sex and height. Materials and Methods: This was a cross-sectional study done over a period of two years (January 2018 to December 2019) in which a total of 300 adults aged between 20-90 years with normal renal function were enrolled. Age and sex of subjects was noted and their heights were measured. All the subjects underwent computed tomographic assessment for kidney size using 384 Slice Somatom Force, Seimens Corp. Multidetected CT machine. Contrast enhanced abdominal CT was performed to visualise the kidneys. Linear renal dimensions (length, lateral diameter, anteriorposterior diameter) were measured and renal volume was calculated using the ellipsoid volume formula. Data was analysed using Statistical Package for the Social Sciences (SPSS) version 21.0 software. Independent samples t-test, paired t-test, Analysis of Variance (ANOVA) and Pearson coefficient constants were calculated. Results: A total of 300 subjects were included, with the mean age of subjects were 41.12 years. Exactly half (50%) were males. Mean kidney size was 94.62 (95% CI: 90.27-98.97) cm3 for right side and 119.84 (95% CI=113.40-126.29) cm3 for left side. Average kidney size was 107.23 (95% CI=102.66-111.80) cm3. For both the sides, males had significantly larger kidney as compared to that of females (p-value <0.01). With increasing age, a significant decline in kidney size was observed (p-value <0.001). With increasing height, a significant increase in kidney size was observed (p-value <0.001). Height showed a significant positive correlation with both right and left side of kidney size (r=0.588, p-value <0.05). Conclusion: The present study provided the normal range for kidney size among North Indian adults using CT. The findings showed an age, gender and height dependence of kidney size in present study population.