Kidney dimensions at sonography: correlation with age, sex, and habitus in 665 adult volunteers.

The purpose of this study was to investigate the normal sonographic measurements of the kidney in adult volunteers.Length, width, and thickness of the kidney and its central echogenic area and the parenchymal thickness of the upper pole were measured in an age- and sex-stratified random sample of 665 volunteers 30, 40, 50, 60, and 70 years old. Measurements were made with the volunteers prone. Volumes of the kidney, the central echogenic area, and the renal parenchyma were calculated. Renal dimensions and renal and parenchymal volume were correlated with age, height, weight, body mass index, and total body area. In 94 subjects, renal length was measured with the volunteers supine also.Median renal lengths were 11.2 cm on the left side and 10.9 cm on the right side. Median renal volumes were 146 cm3 in the left kidney and 134 cm3 in the right kidney. Renal size decreased with age, almost entirely because of parenchymal reduction. Renal volume correlated best with total body area. Renal length correlated be...