title: Agreement between two 3D ultrasound techniques for the assessment of the subpubic arch angle.
abstract: OBJECTIVE
  To assess the reliability of a new three-dimensional (3D) ultrasound technique for the measurement of the subpubic arch angle (SPA) and the agreement between two contrast-enhancing 3D ultrasound techniques.
  
  
  METHODS
  We acquired two static 3D transperineal volumes from 72 nulliparous women using two ultrasound machines equipped with two different 3D contrast enhancement and linear reconstruction softwares: 1. Oblique View Extended Imaging with HD-Volume Imaging (OVIX-HDVI™), Samsung; 2. Omniview with Volume Contrast Imaging (Omniview-VCI™), GE Healthcare. An operator measured SPA once by OVIX-HDVI, and twice by Omniview-VCI, while another operator measured SPA once by Omniview-VCI. We evaluated intra- and inter-observer reproducibility of Omniview-VCI and intermethod agreement. Reproducibility and intermethod agreement were studied by means of intraclass correlation coefficient (ICC) and Bland-Altman method.
  
  
  RESULTS
  Omniview-VCI SPA measurements showed excellent intraobserver and interobserver reproducibility (ICC 0.970; 95% C.I. 0.952 to 0.981, 0.932; 95% C.I. 0.893 to 0.957, respectively). Furthermore, Omniview VCI SPA measurements demonstrated excellent agreement with those performed by OVIX-HDVI technique (ICC 0.943; 95 C.I. 0.911 to 0.964). No systematic difference was found in any of the reliability studies.
  
  
  CONCLUSIONS
  OmniView-VCI is a reliable method for SPA assessment. Both OmniView-VCI and OVIX-HDVI can be used interchangeably for SPA measurement.
authors.affiliation: a Department of Obstetrics and Gynecology , Sant'Orsola-Malpighi Hospital, University of Bologna , Bologna , Italy .
authors.forename: Aly
authors.initials: A
authors.lastname: Youssef
authors.affiliation: a Department of Obstetrics and Gynecology , Sant'Orsola-Malpighi Hospital, University of Bologna , Bologna , Italy .
authors.forename: Ginevra
authors.initials: G
authors.lastname: Salsi
authors.affiliation: a Department of Obstetrics and Gynecology , Sant'Orsola-Malpighi Hospital, University of Bologna , Bologna , Italy .
authors.forename: Ilaria
authors.initials: I
authors.lastname: Cataneo
authors.affiliation: b Department of Obstetrics and Gynecology , Tor Vergata University , Rome , Italy , and.
authors.forename: Federica
authors.initials: F
authors.lastname: Martelli
authors.affiliation: a Department of Obstetrics and Gynecology , Sant'Orsola-Malpighi Hospital, University of Bologna , Bologna , Italy .
authors.forename: Carlotta
authors.initials: C
authors.lastname: Azzarone
authors.affiliation: a Department of Obstetrics and Gynecology , Sant'Orsola-Malpighi Hospital, University of Bologna , Bologna , Italy .
authors.forename: Federica
authors.initials: F
authors.lastname: Bellussi
authors.affiliation: c Department of Obstetrics and Gynecology , University of Parma , Parma , Italy.
authors.forename: Tullio
authors.initials: T
authors.lastname: Ghi
authors.affiliation: a Department of Obstetrics and Gynecology , Sant'Orsola-Malpighi Hospital, University of Bologna , Bologna , Italy .
authors.forename: Gianluigi
authors.initials: G
authors.lastname: Pilu
authors.affiliation: a Department of Obstetrics and Gynecology , Sant'Orsola-Malpighi Hospital, University of Bologna , Bologna , Italy .
authors.forename: Nicola
authors.initials: N
authors.lastname: Rizzo
keywords: Contrast-enhancing techniques; subpubic arch angle; three-dimensional ultrasound