The position and size of radiological nephrogram in Japanese preschool children

The early detection of retroperitoneal masses in children, such as neurobla stoma, Wilm's tumor, hydronephrosis and cystic renal diseases, has a great clinical importance for the improvement of their prognosis. The kidney is o ften affected in its size or position by these lesions, and occasionally al lows clinicians to find a clue to reach the correct diagnosis before the pa tient become symptomatic. Since we had no clinically available nomogram on the position and the size of the kidney in Japanese children, we measured t he size and position of the kidneys on plain abdominal x-rays in 347 Japane se children in preschool years with a special attention to their relationsh ip with the spine. As a result, the nomogram showed age dependent growth of the kidneys keeping almost the same ratio with the spine, while the distan ce between the upper pole of the kidney and the spine remained less than 10 mm in all age groups. Our nomogram may be useful not only fbr picking up t he malposition of the kidneys but also for the follow up of the patients wi th chronic renal diseases affecting the growth of the kidneys. (C) 1999 Toh oku University Medical Press.