Kidney split function in children. A comparative study between renography and planimetry from urography.

The suitability of the background-subtracted renogram as a method for separate kidney function in children was evaluated by comparison with planimetry of the individual renal parenchymal area measured from urography. In different groups of renal disorders the total kidney function as reflected by the glomerular filtration rate has been compared with the sum of right and left renal parenchymal areas. The percentage side distribution of kidney function estimated from the renogram combined with measurements of total glomerular filtration rate has been correlated to individual renal parenchymal area. A good correlation was found for both total and separate measurements. A moderate scatter around the regression lines has to be taken into consideration when kidney function is judged from planimetry. A highly significant correlation was observed between renography and planimetry for the percentage distribution of kidney function, indicating that both methods are well suited for determining the side distribution of kidney function. For calculation of individual kidney function, combination of renography and 51Cr-EDTA-clearance offers a reliable method with a modest dose of irradiation.