Srpski Arhiv za Celokupno Lekarstvo (Jan 2021)

Diagnostic performances and clinical usefulness of comprehensive non-commercial software for renogram analysis: Values of renal output efficiency and normalized residual activity in suspected kidney outflow obstruction

  • Beatović Slobodanka Lj.,
  • Radulović Marija,
  • Durutović Otaš R.,
  • Veljković Miloš M.,
  • Šaponjski Jelena M.,
  • Artiko Vera M.,
  • Šobić-Šaranović Dragana P.

DOI
https://doi.org/10.2298/SARH200520003B
Journal volume & issue
Vol. 149, no. 5-6
pp. 322 – 327

Abstract

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Introduction/Objective. Nuclear Medicine Section of IAEA has developed the software for dynamic renal scintigraphy, which allows calculation of advanced parameters of drainage: renal output efficiency (OE) and normalized residual activity (NORA). The aim of this study was to validate IAEA software by comparing results of parameters of renal drainage in normal subjects against their established reference values and to assess diagnostic accuracy of OE and NORA in distinguishing between obstruction/unobstruction. Methods. Fifty-five patients with suspected obstruction and 36 kidney donors were investigated. Group A consisted of 24 obstructed kidneys, Group B of 37 kidneys with dilated urinary tract, and Group C of 72 normal kidneys. Forty-minute acquisition was applied. Furosemide was administered after 20 minutes. Post-micturition image was acquired at 50 minutes. The analyzed parameters were as follows: OE at 20 minutes (OE20) and at the end of the furosemide test (OE40), NORA at 20 minutes (NORA20) and after micturition (NORAPM). One-way ANOVA was used for evaluating the differences between the groups. Ability of OE40 and NORAPM to distinguish between obstruction/unobstruction was determined by ROC curve analysis. The sensitivity, specificity, area under the curve, and cut-off values were analyzed. Results. Excellent agreement of our results with established OE and NORA values was found. The difference between the groups was significant for OE20, OE40, NORA20, and NORAPM (p < 0.001). Cut-off values for obstruction were 82% and 0.11 for OE40 and NORAPM, respectively. Conclusion. IAEA software gives reliable analysis of diuretic renography and helps to better diagnose obstruction. IAEA should be encouraged to produce final version of the software and to release it online.

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