title: Correlation of ultrasound estimated with dye-determined or directly measured amniotic fluid volume revisited.
abstract: OBJECTIVE
  To examine the relationship of the amniotic fluid index (AFI) and single deepest pocket (SDP) with an AFV as modelled by Brace or Magann.
  
  
  METHODS
  AFI and SDP were evaluated for their correlation with an actual AFV using the Spearman correlation coefficient.
  
  
  RESULTS
  482 AFI and 468 SDP pregnancies were evaluated. There was a significant association between the AFI and SDP and an actual AFV (p < 0.0001). The AFI range of 5.1-20 was better correlated than 5.1-24 for normal AFVs Brace (κ = 0.175) and Magann (κ = 0.356) versus 5.1-24 (κ = 0.150 and κ = 0.319), respectively. The agreement level t for the AFI (κ = 0.175) and SDP (κ = 0.126) using Brace was slight and for the AFI (κ = 0.356) and SDP (κ = 0.295) using Magann was fair.
  
  
  CONCLUSIONS
  Both the AFI and SDP were correlated with actual AFV using both models. AFI of 5.1-20 better categorizes normal volumes. Although the Magann model correlates AFI/SDP and AFV better, the superiority is minimal.
authors.affiliation: Department of Obstetrics and Gynecology, University of Arkansas for Medical Sciences, Little Rock, Ark., USA.
authors.forename: Everett F
authors.initials: EF
authors.lastname: Magann
authors.forename: Songthip
authors.initials: S
authors.lastname: Ounpraseuth
authors.forename: Suneet P
authors.initials: SP
authors.lastname: Chauhan
authors.forename: Anaanth S
authors.initials: AS
authors.lastname: Ranganathan
authors.forename: Nafisa K
authors.initials: NK
authors.lastname: Dajani
authors.forename: Jennifer
authors.initials: J
authors.lastname: Bergstrom
authors.forename: John C
authors.initials: JC
authors.lastname: Morrison
mesh_terms: D000328:Adult; D000653:Amniotic Fluid / Q000000981:diagnostic imaging*; D055592:Biophysical Phenomena; D004395:Dye Dilution Technique; D005260:Female; D005865:Gestational Age; D006801:Humans; D016104:Oligohydramnios / Q000000981:diagnostic imaging; D006831:Polyhydramnios / Q000000981:diagnostic imaging; D011247:Pregnancy; D012189:Retrospective Studies; D016216:Ultrasonography, Prenatal