title: Quantitative Ultrasound for Measuring Obstructive Severity in Children with Hydronephrosis.
abstract: OBJECTIVE
  We define sonographic biomarkers for hydronephrotic renal units that can predict the necessity of diuretic nuclear renography.
  
  
  METHODS
  We selected a cohort of 50 consecutive patients with hydronephrosis of varying severity in whom 2-dimensional sonography and diuretic mercaptoacetyltriglycine renography had been performed. A total of 131 morphological parameters were computed using quantitative image analysis algorithms. Machine learning techniques were then applied to identify ultrasound based safety thresholds that agreed with the t½ for washout. A best fit model was then derived for each threshold level of t½ that would be clinically relevant at 20, 30 and 40 minutes. Receiver operating characteristic curve analysis was performed. Sensitivity, specificity and area under the receiver operating characteristic curve were determined. Improvement obtained by the quantitative imaging method compared to the Society for Fetal Urology grading system and the hydronephrosis index was statistically verified.
  
  
  RESULTS
  For the 3 thresholds considered and at 100% sensitivity the specificities of the quantitative imaging method were 94%, 70% and 74%, respectively. Corresponding area under the receiver operating characteristic curve values were 0.98, 0.94 and 0.94, respectively. Improvement obtained by the quantitative imaging method over the Society for Fetal Urology grade and hydronephrosis index was statistically significant (p <0.05 in all cases).
  
  
  CONCLUSIONS
  Quantitative imaging analysis of renal sonograms in children with hydronephrosis can identify thresholds of clinically significant washout times with 100% sensitivity to decrease the number of diuretic renograms in up to 62% of children.
authors.affiliation: Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Health System, Washington, D.C.. Electronic address: jcerrola@childrensnational.org.
authors.forename: Juan J
authors.initials: JJ
authors.lastname: Cerrolaza
authors.affiliation: Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Health System, Washington, D.C.; Division of Urology and Pediatrics, Children's National Health System, Washington, D.C.. Electronic address: crpeters@childrensnational.org.
authors.forename: Craig A
authors.initials: CA
authors.lastname: Peters
authors.affiliation: Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Health System, Washington, D.C.; Division of Urology and Pediatrics, Children's National Health System, Washington, D.C.
authors.forename: Aaron D
authors.initials: AD
authors.lastname: Martin
authors.affiliation: Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Health System, Washington, D.C.
authors.forename: Emmarie
authors.initials: E
authors.lastname: Myers
authors.affiliation: Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, Georgia.
authors.forename: Nabile
authors.initials: N
authors.lastname: Safdar
authors.affiliation: Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Health System, Washington, D.C.; Departments of Radiology and Pediatrics, School of Medicine and Health Science, George Washington University, Washington, D.C.
authors.forename: Marius George
authors.initials: MG
authors.lastname: Linguraru
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D006869:Hydronephrosis / Q000000981:diagnostic imaging* / Q000209:etiology; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D011866:Radioisotope Renography; D012189:Retrospective Studies; D012720:Severity of Illness Index; D014517:Ureteral Obstruction / Q000150:complications / Q000000981:diagnostic imaging*
keywords: biological markers; hydronephrosis; kidney; technetium Tc 99m mertiatide; ultrasonography