RT Journal Article
SR Electronic
T1 The usefulness of normalized residual activity (NORA) in the analysis of Tc-99m DTPA diuresis renography
JF Journal of Nuclear Medicine
JO J Nucl Med
FD Society of Nuclear Medicine
SP 1368
OP 1368
VO 62
IS supplement 1
A1 Yassir Benameur
A1 Salah Oueriagli
A1 Omar Ait Sahel
A1 Abdelhamid Biyi
A1 Abderrahim Doudouh
YR 2021
UL http://jnm.snmjournals.org/content/62/supplement_1/1368.abstract
AB 1368Introduction: Normalized residual activity (NORA) is a simple parameter that allows quantifying the renal drainage. NORA is easy to program, as it requires only the activity at a given time (for instance, at the end of the renogram or on the postmicturition data) and the renal activity between 1 and 2 min after tracer injection. It has a great advantage, in contrast to the classical empirical parameters, of being independent of the differential renal function. The objective of this study is to investigate the robustness of the NORA for the estimation of renal emptying during renography in case of indeterminate response after diuretic stress. Subjects and Methods: 47 patients: 22 children (10 boys and 12 girls) the mean age was about 6.15 years (ranges from 3 months to 17 years old) and 25 adults (mean age: 40.28 years). The main causes of the conditions of hydronephrosis were ureteropelvic junction obstruction in 31 cases (66%). All of the patients investigated had indeterminate response after diuretic. 40-minutes acquisition with 120 20sec images was applied. Furosemide was administered after 20min (F+20). Post-void static images acquired at 50min. Normalized residual activity on post-micturition acquisition (NORAPM) was calculated for all patients. Results: Normalized residual activity on post-micturition acquisition (NORAPM) was calculated in 47 cases in wich kidney washout was not ameliorated by the diuretic stress test. Among them 19 were reclassified into normal renal drain with NORAPM: 0.70±0.15 (mean±SD). And 28 into obstructive origin, with NORAPM: 1.35±0.25 (mean±SD), 7 of them had less contribution in total renal function and have been proposed for surgery, for all others a scintigraphic follow up has been established. Conclusions: Diuretic renal scintigraphy is considered as the most appropriate method that allows the evaluation of renal drainage. In case of indeterminate response after diuretic stress, classical empirical parameters are inconclusive; NORA is an extremely simple parameter and robust method that fits better to reclassify these patients and has the great advantage to be less dependent on the level of overall function than the traditional parameters.