title: Angle correction can be used to measure peak systolic velocity in the fetal middle cerebral artery.
abstract: OBJECTIVE
  The objective of the study was to compare Doppler ultrasound measurements of the fetal middle cerebral artery peak systolic velocity (MCA-PSV) obtained at a 0 degrees angle of insonation to assessment at 30 degrees and 30 degrees with angle correction.
  
  
  METHODS
  Patients between 14 and 36 weeks' gestation were enrolled (n = 66). MCA-PSV measurements were assessed at 0 degrees , 30 degrees , and 30 degrees with angle correction. The data were analyzed using a mixed model adjusted for gestational age. Pairwise comparisons of mean MCA-PSV measurements were made using the Tukey multiple comparison test.
  
  
  RESULTS
  All measurements were obtained for 50 fetuses (76%). Mean MCA-PSV measurements were statistically different between 0 degrees vs 30 degrees (P = .03 to < .001) but not between 0 degrees vs 30 degrees with angle correction (P = .34-.99) at each of the 5 gestational age groupings.
  
  
  CONCLUSIONS
  Assessment of the MCA-PSV at 0 degrees and 30 degrees with angle correction provides comparable measurements during the second and third trimester of pregnancy.
authors.affiliation: Perinatal Associates of New Mexico, Ltd, Albuquerque, NM, USA.
authors.forename: Michael S
authors.initials: MS
authors.lastname: Ruma
authors.forename: Anthony E
authors.initials: AE
authors.lastname: Swartz
authors.forename: Eunhee
authors.initials: E
authors.lastname: Kim
authors.forename: Amy H
authors.initials: AH
authors.lastname: Herring
authors.forename: M Kathryn
authors.initials: MK
authors.lastname: Menard
authors.forename: Kenneth J
authors.initials: KJ
authors.lastname: Moise