title: Reproducibility study of fetal 3-D volumetry in the first trimester: effect of fetal size and rotational angle of VOCAL software.
abstract: Intra- and inter-observer reproducibility of fetal volume measurement by 3-D ultrasound scan (using VOCAL [Virtual Organ Computer-Aided Analysis] software) in 27 fetuses at 7 to 13 wk was studied. For intra-observer variability, the mean difference (MD) and 95% limits of agreement (95% LOA) at 12°, 18° and 30° were MD(12) = 0.097, 95% LOA(12) = -0.87 to +1.06; MD(18) = 0.07, 95% LOA(18) = -1.31 to +1.45; and MD(30) = -0.07, 95% LOA(30) = -1.55 to +1.41. The standard deviation of the differences (SD(DIF)) increased with crown-rump length at 12° (p = 0.0016), 18° (p = 0.0011) and 30° (p = 0.02). For inter-observer variability, MD(12) = 0.15, 95% LOA(12) = -1.65 to +1.95; MD(18) = 0.042, 95% LOA(18) = -1.79 to +1.87; and MD(30) = 0.19, 95% LOA(30) = -1.24 to +1.62. SDDIF increased with crown-rump length at 18° (p = 0.0084) and 30° (p = 0.0073). The accuracy of fetal volume measurement was not influenced by rotational angle or fetal size. Precision deteriorated for wider rotational angles and larger fetuses.
authors.affiliation: Fetal Medicine Unit, 3rd Department of Obstetrics and Gynaecology, University of Athens, Attikon University Hospital, Athens, Greece. Electronic address: jdpap2@yahoo.co.uk.
authors.forename: Ioannis
authors.initials: I
authors.lastname: Papastefanou
authors.affiliation: Fetal Medicine Unit, 3rd Department of Obstetrics and Gynaecology, University of Athens, Attikon University Hospital, Athens, Greece.
authors.forename: Dimitra
authors.initials: D
authors.lastname: Kappou
authors.affiliation: Fetal Medicine Unit, 3rd Department of Obstetrics and Gynaecology, University of Athens, Attikon University Hospital, Athens, Greece.
authors.forename: Athena P
authors.initials: AP
authors.lastname: Souka
authors.affiliation: Fetal Medicine Unit, 3rd Department of Obstetrics and Gynaecology, University of Athens, Attikon University Hospital, Athens, Greece.
authors.forename: Athanasios
authors.initials: A
authors.lastname: Pilalis
authors.affiliation: Fetal Medicine Unit, 3rd Department of Obstetrics and Gynaecology, University of Athens, Attikon University Hospital, Athens, Greece.
authors.forename: Charalambos
authors.initials: C
authors.lastname: Chrelias
authors.affiliation: Fetal Medicine Unit, 3rd Department of Obstetrics and Gynaecology, University of Athens, Attikon University Hospital, Athens, Greece.
authors.forename: Charalambos
authors.initials: C
authors.lastname: Siristatidis
authors.affiliation: Fetal Medicine Unit, 3rd Department of Obstetrics and Gynaecology, University of Athens, Attikon University Hospital, Athens, Greece.
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Kassanos
mesh_terms: D003430:Cross-Sectional Studies; D018568:Crown-Rump Length; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods* / Q000706:statistics & numerical data; D015588:Observer Variation; D011247:Pregnancy; D011261:Pregnancy Trimester, First / Q000502:physiology*; D011446:Prospective Studies; D015203:Reproducibility of Results; D012984:Software; D016216:Ultrasonography, Prenatal / Q000379:methods* / Q000706:statistics & numerical data
keywords: 3-D ultrasound; Accuracy; Fetal volume; First-trimester ultrasound scan; Precision; Reproducibility; Virtual organ computer-aided analysis