Diagnostic performance of IAEA software package for the analysis of scintigraphic renal dynamic studies: Preliminary results for semi-quantitative parameters of technetium-99m mercapto-acetyltriglycine renogram in healthy individuals

Abstract

The aims of this study in healthy individuals were: a) to implement the International Atomic Energy Agency (IAEA) Software Package into analysis of technetium-99m mercapto-acetyltriglycine (99mTc MAG3) dynamic scintigraphy, b) to validate results of renogram parameters against their reference values, and c) to compare different renogram indices of kidney excretion in order to assess whether the clinical information provided by all of them is identical. Study population consisted of 20 healthy subjects who were evaluated by 99mTc MAG3 dynamic scintigraphy for kidney donation. The IAEA software was applied to process the studies. The parameters analyzed were: time to maximum activity (Tmax), time to half maximum (T1/2) of the curves, normalized residual activity at 20 minutes (NORA 20), output efficiency at 20 minutes (OE 20), residual activity (RA), elimination index (EI), whole kidney mean transit time (MTT), mean parenchymal transit time (MPTT) and relative kidney function (RF). Correspondence between OE 20, NORA 20, RA and EI was evaluated by Pearson correlation coefficient and linear regression analysis. The results for normal kidneys were presented as follows: Tmax: 3.4+0.7 min; T1/2:6.1+1.5min; NORA20:0.34+0.09;OE20: 93+2.2%; RA: 26+6.2%; EI: 2.2+0.4; MTT: 2.+0.4 min and MPTT: 1.7+0.4 min. Relative function for the left and right kidney was 52% and 48%+.4%, respectively. The excellent agreement was observed between the obtained values of renogram parameters and their reference values. Significant linear correlation between parameters of kidney excretion was obtained. The highest correlation was observed between NORA 20 and OE 20 (r=-0.936, p< 0.01). In Conclusion, the IAEA Software gives reliable values of numerical parameters of kidney excretion. Results obtained for normal kidneys were almost identical with previously reported reference values for MAG3 parameters. Only the results for MTT and MPTT were systematically lower than the established normal values. NORA 20 highly corresponds with OE 20 and could replace the former parameter in the evaluation of kidney drainage. The preliminary results support the wide-spread use of IAEA software package in order to standardize the technique of dynamic renal scintigraphy.