title: A review of fetal volumetry: the need for standardization and definitions in measurement methodology.
abstract: Volume charts of fetal organs and structures vary considerably among studies. This review identified 42 studies reporting normal volumes, namely for fetal brain (n = 3), cerebellum (n = 4), liver (n = 6), femur (n = 2), lungs (n = 15), kidneys (n = 3) and first-trimester embryo (n = 9). The differences among median volumes were expressed both in percentage form and as standard deviation scores. Wide discrepancies in reported normal volumes make it extremely difficult to diagnose pathological organ growth reliably. Given its magnitude, this variation is likely to be due to inconsistencies in volumetric methodology, rather than population differences. Complicating factors include the absence of clearly defined anatomical landmarks for measurement; inadequate assessment and reporting of method repeatability; the inherent difficulty in validating fetal measurements in vivo against a reference standard; and a multitude of mutually incompatible three-dimensional (3D) imaging formats and software measuring tools. An attempt to standardize these factors would improve intra- and inter-researcher agreement concerning reported volumetric measures, would allow generalization of reference data across different populations and different ultrasound systems, and would allow quality assurance in 3D fetal biometry. Failure to ensure a quality control process may hamper the wide use of 3D ultrasound.
authors.affiliation: Nuffield Department of Obstetrics and Gynaecology, University of Oxford, Oxford, UK.
authors.forename: C
authors.initials: C
authors.lastname: Ioannou
authors.forename: I
authors.initials: I
authors.lastname: Sarris
authors.forename: L J
authors.initials: LJ
authors.lastname: Salomon
authors.forename: A T
authors.initials: AT
authors.lastname: Papageorghiou
mesh_terms: D001921:Brain / Q000196:embryology*; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging / Q000196:embryology*; D047109:Fetal Development; D006801:Humans; D021621:Imaging, Three-Dimensional; D007668:Kidney / Q000000981:diagnostic imaging / Q000196:embryology*; D008099:Liver / Q000000981:diagnostic imaging / Q000196:embryology*; D008168:Lung / Q000000981:diagnostic imaging / Q000196:embryology*; D009929:Organ Size; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011786:Quality Control; D012015:Reference Standards; D015203:Reproducibility of Results; D016216:Ultrasonography, Prenatal / Q000379:methods / Q000592:standards*