Ultrasonographic renal size in individuals without known renal disease

In order to establish some preliminary data of our population, we determined the ultrasonographic kidney dimensions in individuals without known renal disease. We assessed whether age, sex, side, body mass index (BMI) and presence or absence of diabetes mellitus and hypertension affect the renal size.

Ultrasonographic kidney measurements were performed on 194 adult patients without known kidney lesions. Measurements included length, width, cortical thickness and estimation of renal size which was obtained by multiplying the first three variables. The effect of age, gender, side, height, weight, BMI, hypertension and diabetes mellitus was statistically analyzed.

The mean kidney length was 10.4 +/- 0.8 cm, mean with 4.5 +/- 0.6 cm and mean cortical thickness 1.6 +/- 0.2 cm. The estimated mean renal size was 76 +/- 22 cm3. Kidney length did not significantly differ between right and left, however, kidney width, cortical thickness and size did (p < 0.05). Right kidneys were smaller than the left ones. In univariate analysis, the mean renal size correlated with age, sex, side, BMI and absence or presence of hypertension and diabetes mellitus. In a multivariate analysis, however, the only significant factors affecting renal size were sex and BMI.

We conclude that renal size is related to age, side, sex and the individual's height and weight. Population-based studies are needed to establish the normal values for the Pakistani population.