title: The use of renal Doppler ultrasonography to diagnose patent ductus arteriosus in preterm infants.
abstract: OBJECTIVE
  To prospectively study the diagnostic usefulness of altered renal waveforms in patent ductus arteriosus.
  
  
  METHODS
  We studied preterm infants undergoing echocardiography for a suspected patent ductus arteriosus. A spectral Doppler display was acquired for both renal arteries, and a resistive index was obtained. Sensitivity, specificity, and likelihood ratios were calculated using a clinically significant patent ductus arteriosus (>1.5-mm diameter on color Doppler ultrasonography) as the standard of reference.
  
  
  RESULTS
  Fifty infants had 78 scans. A significant patent ductus arteriosus was present on 39 scans. When the renal resistive index was greater than 1.0, the likelihood ratio for a significant patent ductus arteriosus was 24.8 (specificity, 97.2%; SD, 3.8%). When the renal resistive index was 1.0 or less, the likelihood ratio for a significant patent ductus arteriosus was 0.2 (sensitivity, 77.2%; SD, 9.4%).
  
  
  CONCLUSIONS
  Renal resistive index measurement is a simple investigation that can predict a significant patent ductus arteriosus in patients without congenital heart disease or other causes of diastolic runoff when echocardiography is unavailable.
authors.affiliation: Newborn Services, National Women's Hospital, Auckland, New Zealand.
authors.forename: D L
authors.initials: DL
authors.lastname: Armstrong
authors.forename: R L
authors.initials: RL
authors.lastname: Teele
authors.forename: C A
authors.initials: CA
authors.lastname: Kuschel
authors.forename: J E
authors.initials: JE
authors.lastname: Harding
mesh_terms: D004374:Ductus Arteriosus, Patent / Q000000981:diagnostic imaging*; D004452:Echocardiography; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D019102:Infant, Very Low Birth Weight; D007668:Kidney / Q000098:blood supply / Q000000981:diagnostic imaging*; D008297:Male; D011446:Prospective Studies; D012372:ROC Curve; D012680:Sensitivity and Specificity; D018608:Ultrasonography, Doppler; D014655:Vascular Resistance