Abstract
Objective
Children with unilateral hydronephrosis are followed up with anteroposterior pelvic diameter (APD), hydronephrosis grade, mercaptoacetyltriglycine (MAG-3) drainage pattern and differential renal function (DRF). Indeterminate drainage preserved DRF in higher grades of hydronephrosis, in some situations, complicating the decision-making process. Due to an asymmetric renal area ratio, falsely negative DRF estimations can result in missed optimal surgery times. This study was designed to assess whether correcting the DRF estimation according to kidney area could reflect the clinical situation of a hydronephrotic kidney better than a classical DRF calculation, concurrently with the hydronephrosis grade, APD and MAG-3 drainage pattern.
Materials and methods
We reviewed the MAG-3, dimercaptosuccinic acid (DMSA) scans and ultrasonography (US) of 23 children (6 girls, 17 boys, mean age: 29 ± 50 months) with unilateral hydronephrosis. MAG-3 and DMSA scans were performed within 3 months (mean 25.4 ± 30.7 days). The closest US findings (mean 41.5 ± 28.2 days) were used. DMSA DRF estimations were obtained using the geometric mean method. Secondary calculations were performed to correct the counts (the total counts divided by the number of pixels in ROI) according to kidney area. The renogram patterns of patients were evaluated and separated into subgroups. The visual assessment of DMSA scans was noted and the hydronephrotic kidney was classified in comparison to the normal contralateral kidney’s uptake. The correlations of the DRF values of classical and area-corrected methods with MAG-3 renogram patterns, the visual classification of DMSA scan, the hydronephrosis grade and the APD were assessed.
Results
DRF estimations of two methods were statistically different (p: 0.001). The categories of 12 hydronephrotic kidneys were changed. There were no correlations between classical DRF estimations and the hydronephrosis grade, APD, visual classification of the DMSA scan and uptake evaluation. The DRF distributions according to MAG-3 drainage patterns were not different. Area-corrected DRF estimations correlated with all: with an increasing hydronephrosis grade and APD, DRF estimations decreased and MAG-3 drainage patterns worsened. A decrease in DRF (<45 %) was determined when APD was ≥10 mm. When APD was ≥26 mm, a reduction of DRF below 40 % was determined.
Conclusion
Our results suggest that correcting DRF estimation for asymmetric renal area ratio in unilateral hydronephrosis can be more robust than the classical method, especially for higher grades of hydronephrotic kidneys, under equivocal circumstances.
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References
Longpre M, Nguan A, MacNeily EA, Afshar K. Prediction of the outcome of antenatally diagnosed hydronephrosis: a multivariable analysis. J Pediatr Urol. 2012;8:135–9.
Piepsz A, Gordon I, Brock J, Koff S. Round table on management of renal pelvic dilatation in children. J Pediatr Urol. 2009;5:437–44.
Piepsz A, Colorinha P, Gordon I, Hahn K, Oliver P, Roca I. European Associations of Nuclear Medicine guidelines on c-99 m DMSA scintigraphy in children. Eur J Nucl Med. 2001;28(3):37–41.
Nguyen HT, Herndon CD, Cooper C, Gatti J, Kirsch A, Kokorowski P, et al. The Society for fetal Urology consensus statement on the evaluation and management of antenatal hydronephrosis. J Pediatr Urol. 2010;6:212–31.
Inanir S, Biyikli N, Noshary O, Caliskan B, Tugtepe H, Erdil TY, et al. Contradictory supranormal function in hydronephrotic kidneys: fact or artifact on pediatric MAG-3 renal scans. Clin Nucl Med. 2005;30:91–6.
Piepsz A, Blaufox MD, Gordon I, Granerus G, Majd M, O’Reilly P, et al. Consensus on renal cortical scintigraphy in children with urinary tract infection. Semin Nucl Med. 1999;29:160–74.
Capolicchio G, Jednak R, Dinh L, Salle JL, Brzezinski A, Houle AM. Supranormal renographic differential renal function in congenital hydronephrosis: fact, not artifact. J Urol. 1999;161:1290–4.
Aktas GE, Inanir S. Relative renal function with MAG-3 and DMSA in children with unilateral hydronephrosis. Ann Nucl Med. 2010;24:691–5.
Kabasakal L, Turkmen C, Ozmen O, Alan N, Onsel C, Uslu I. Is frusemide administration effective in improving the accuracy of determination of differential renal function by means of technetium-99 m DMSA in patients with hydronephrosis? Eur J Nucl Med. 2002;29:1433–7.
Gungor F, Anderson P, Gordon I. Effect of the size of regions of interest on estimation of differential renal function in children with congenital hydronephrosis. Nucl Med Commun. 2002;23:147–51.
Oh SJ, Moon DH, Kang W, Park YS, Park T, Kim KS. Supranormal differential renal function is real but may be pathological: assessment by Tc-99 m mercaptoacetylglycine renal scan of congenital unilateral hydronephrosis. J Urol. 2001;165:2300–4.
Evans K, Lythgoe MF, Anderson PJ, Smith T, Gordon I. Biokinetic behavior of technetium-99 m-DMSA in children. J Nucl Med. 1996;37:1331–5.
Konda R, Sakai K, Ota S, Abe Y, Hatakeyama T, Orikasa S. Ultrasound grade of hydronephrosis and severity of renal cortical damage on 99 m technetium dimercaptosuccinic acid renal scan in infants with unilateral hydronephrosis during followup and after pyeloplasty. J Urol. 2002;167:2159–63.
Ross SS, Kardos S, Krill A, Bourland J, Sprague B, Majd M, et al. Observation of infants with SFU grades 3–4 hydronephrosis: worsening drainage with serial diuresis renography indicates surgical intervention and helps prevent loss of renal function. J Pediatr Urol. 2011;7:266–71.
Burgu B, Aydoğdu O, Soygur T, Baker L, Snodgrass W, Wilcox D. When is it necessary to perform nuclear renogram in patients with a unilateral neonatal hydronephrosis? World J Urol. 2002;30:347–52.
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Aktaş, G.E., Sarıkaya, A. Correction of differential renal function for asymmetric renal area ratio in unilateral hydronephrosis. Ann Nucl Med 29, 816–824 (2015). https://doi.org/10.1007/s12149-015-1009-z
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DOI: https://doi.org/10.1007/s12149-015-1009-z