Glomerular Filtration Assessed with 99mTc-DTPA by Diuretic Dynamic Scintigraphy vs. Calculation according to Schwartz

Overview

The authors assessed in children with congenital obstruction of the urinary tract the correlation between values of glomerular filtration assessed by 99mTc-DTPA using diuretic dynamic scintigraphy applying Gates’ method with the calculated value of glomerular filtration using the formula elaborated by Schwartz. They made a total of 69 examinations in 63 patients aged 16 days to 4.5 years. The group was divided into three age groups: 16 - 90 days, 91 - 365 days and more than 365 days. In the whole group the authors found a low but statistically significant relationship (r = 0.535, alpha = 0.05) between the used methods. The differentiation of the group by age did not reveal a statistically significant difference between individual groups. 99mTc-DTPA diuretic scintigraphy underestimates values of glomerular filtration as compared with values calculated according to Schwartz’ formula. The results suggest a great scatter of glomerular filtration values assessed by the two methods. Satisfactory correlation assessed by the two methods of assessment of glomerular filtration was not confirmed in children under 4.5 years. The authors do not recommend to rely on the absolute value of glomerular filtration assessed by scintigraphy.

Key words:
glomerular filtration, 99mTc-DTPA diuretic dynamic scintigraphy, children, obstructional uropathy, Schwartz’ formula