Volumetric evaluation of fat in the renal sinus in normal subjects using stereological method on computed tomography images and its relationship with body composition.

BACKGROUND The aim of the study was: to describe a simple, accurate and practical technique for estimating the volume of adipose tissue within the renal sinus (RS) using stereological method on computed tomography (CT) images; to establish a population database for volume of fat within the RS from 21 to 80 years of age; to investigate the effect of age, gender, body mass index (BMI) and abdominal diameters on RS fat volume in normal subjects. MATERIALS AND METHODS We retrospectively reviewed abdominal CT examinations of 240 patients without renal pathology between the ages of 21 and 80 years. There were 6 groups of patients, with 40 patients for each decade. RESULTS RS fat volumes in the left and right kidney were 5.70 ± 2.87 cm³ and 4.15 ± 2.39 cm³, respectively, in males and 3.51 ± 2.67 cm³ and 2.49 ± 2.16 cm³, respectively, in females. RS fat volume and age were positively correlated for both kidneys (left: r = 0.46; right: r = 0.44; p < 0.001, both), though it appeared to decline after age 70. CONCLUSIONS Quantitative data may allow clinicians to better estimate the age-related RS fat volume changes and help them in decision making.