Knowledge of normal renal dimensions is essential for the accurate ealuation of abnormal kidneys. There have been many reports for the measurement of the normal renal size in children. But there was some variability in the apparent size of the
kidneys,
because most them was performed by the intravenous pyelography using contrast dye. The radiographic technique itself yields some variability due to differences in centering of the tube and its distance from the patient, phase of respiration, and
osmotic
effects of the iodinated contrast material. Sonography allows measurements that are not subject to the above variables and furthermore provides such information without exposing the patient to ionizing radiation. Using real time sonography, we
prospectively analzyed 536 kidneys in 268 children without apparent urinary tract disease to determine the normal renal dimensions as correlated with age and body size. The maximal renal length was recorded after adjusting the angle of the
transducer to
bring the long axis of the kindey perpendicular to the central beam of the transducer. At the same angle, the transducer was rotated 90°into the axial plane, and anteroposteror and transverse measurements were made through the renal hilum. On
average,
the left kidney was longer and larger than the right kidney, with a mean difference of 0.8mm and 2.63㎤, even though it was not significnat statistically. Renal dimensions were well correlated with age, height, weight, and body surface area. And
body
surface area was more correlated with renal dimensions than other ffactors. Renal length could be calculated from the equation: Y=3.9323X+4.3193, when Y is length of the kidney in centimeters, and X is body surface area in mE2. And renal volume
could be
calculated from the equation: Y=68.1X-5.1683, when Y is volume of the kidney in ㎤, and X is body surface area in ㎡. The present study provides a valuable baseline data for various dmensions. And renal dimersions can be readily estimated from
the
derived equations.
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