title: Transverse comparisons between ultrasound and radionuclide parameters in children with presumed antenatally detected pelvi-ureteric junction obstruction.
abstract: OBJECTIVE
  The main criteria used for deciding on surgery in children with presumed antenatally detected pelviureteric junction obstruction (PPUJO) are the level of hydronephrosis (ultrasonography), the level of differential renal function (DRF) and the quality of renal drainage after a furosemide challenge (renography), the importance of each factor being far from generally agreed. Can we predict, on the basis of ultrasound parameters, the patient in whom radionuclide renography can be avoided?
  
  
  METHODS
  We retrospectively analysed the medical charts of 81 consecutive children with presumed unilateral PPUJO detected antenatally. Ultrasound and renographic studies performed at the same time were compared. Anteroposterior pelvic diameter (APD) and calyceal size were both divided into three levels of dilatation. Parenchymal thickness was considered either normal or significantly decreased. Acquisition of renograms under furosemide stimulation provided quantification of DRF, quality of renal drainage and cortical transit.
  
  
  RESULTS
  The percentages of patients with low DRF and poor drainage were significantly higher among those with major hydronephrosis, severe calyceal dilatation or parenchymal thinning. Moreover, impaired cortical transit, which is a major risk factor for functional decline, was seen more frequently among those with very severe calyceal dilatation. However, none of the structural parameters obtained by ultrasound examination was able to predict whether the level of renal function or the quality of drainage was normal or abnormal. Alternatively, an APD <30 mm, a calyceal dilatation of <10 mm and a normal parenchymal thickness were associated with a low probability of decreased renal function or poor renal drainage.
  
  
  CONCLUSIONS
  In the management strategy of patients with prenatally detected PPUJO, nuclear medicine examinations may be postponed in those with an APD <30 mm, a calyceal dilatation of <10 mm and a normal parenchymal thickness. On the contrary, precise estimation of DRF and renal cortical transit should be performed in patients with APD >30 mm, major calyceal dilatation and/or parenchymal thinning.
authors.affiliation: Department of Pediatric Nephrology, Hôpital Universitaire des Enfants - Reine, Fabiola, Université Libre de Bruxelles (ULB), 322, Rue Haute, B-1000, Brussels, Belgium.
authors.forename: Hong Phuoc
authors.initials: HP
authors.lastname: Duong
authors.forename: Amy
authors.initials: A
authors.lastname: Piepsz
authors.forename: Karim
authors.initials: K
authors.lastname: Khelif
authors.forename: Frank
authors.initials: F
authors.lastname: Collier
authors.forename: Kathia
authors.initials: K
authors.lastname: de Man
authors.forename: Nash
authors.initials: N
authors.lastname: Damry
authors.forename: Françoise
authors.initials: F
authors.lastname: Janssen
authors.forename: Michelle
authors.initials: M
authors.lastname: Hall
authors.forename: Khalid
authors.initials: K
authors.lastname: Ismaili
mesh_terms: D006801:Humans; D006869:Hydronephrosis / Q000151:congenital* / Q000000981:diagnostic imaging; D007223:Infant; D021782:Multicystic Dysplastic Kidney / Q000000981:diagnostic imaging*; D011866:Radioisotope Renography; D016216:Ultrasonography, Prenatal; D014517:Ureteral Obstruction / Q000000981:diagnostic imaging*