Fetal biometry: how well can offline measurements from three-dimensional volumes substitute real-time two-dimensional measurements?

Abstract

Objectives To assess the feasibility, accuracy and reproducibility of manipulating three-dimensional (3D)

Ultrasound Quality Assurance for Singletons in the National Institute of Child Health and Human Development Fetal Growth Studies

“…That is, the sonographer is not blinded to which participants are selected for reliability 17 . A novel scheme using archived 3‐dimensional volumes to remeasure for 2‐dimensional reliability was recently used by the International Fetal and Newborn Growth Consortium for the 21st Century study, and while this approach may overcome some of the issues associated with conventional QC, it was noted that acquisition of the volumes added considerable time to the visit, and there was some unanticipated difficulty in manipulating the 3‐dimensional volumes and locating the correct planes or positions for measuring some of the linear dimensions 18 . For example, measurements were systematically smaller when using 3‐dimensional volumes acquired when the head was facing anterior and posterior or when the long axis of the femur was perpendicular to the transducer.…”

International standards for fetal brain structures based on serial ultrasound measurements from Fetal Growth Longitudinal Study ofINTERGROWTH‐21stProject

“…Detailed descriptions of the volume acquisition methods are provided elsewhere 25,29 . Briefly, head volumes were acquired at the level of the axial transthalamic plane.…”

“…It is possible that measurements acquired on planes extracted from 3D volumes are not equivalent to measurements made from 2D image acquisition. Although volumetry is associated with a high degree of variability if not standardized 50 , once rigorous methodology is adopted, 2D measurements from reconstructed planes can be as reproducible as measurements obtained in real time 29,37 . A key strength of our study is that we adopted a prescriptive design, as recommended by the WHO.…”

Fetal cerebellar growth and Sylvian fissure maturation: international standards from Fetal Growth Longitudinal Study ofINTERGROWTH‐21stProject

“…Most of these were obtained after 32 weeks' gestation when visualization and assessment of brain structures are hampered by acoustic shadowing of the calcified fetal skull, fetal head position in the maternal pelvis and a reduction in amniotic fluid volume 37,42,52 . Other reasons for images of limited quality were fetal movement artifact not evident during the original scan, acoustic shadows from proximal structures, reverberation artifacts and unfavorable fetal head orientation 22,37 . After these exclusions and removal of 11 outliers, 3016 and 2359 volumes from 1130 fetuses were available for TCD and SF analysis, respectively.…”