Leonie Baken

First-trimester crown–rump length and embryonic volume of aneuploid fetuses measured in virtual reality

To examine whether embryonic volume (EV), as measured using three‐dimensional (3D) ultrasound and a virtual reality approach, is a better measure of growth restriction than is crown–rump length (CRL) in aneuploid fetuses.

Diagnostic techniques and criteria for first-trimester conjoined twin documentation: a review of the literature illustrated by three recent cases.

Objectives Conjoined twins are rare. High-quality imaging techniques are essential for proper first-trimester diagnosis. Technological development leads to new imaging techniques such as 3-dimensional virtual embryoscopy. The aim of this review was to explore imaging techniques used in the first-trimester diagnosis of conjoined twins and provide a systematic diagnostic table for making this diagnosis. Design A PubMed literature search was performed using the terms ultrasound, Doppler, MRI, and CT combined with first-trimester and conjoined twins. Three recent cases at our department are reviewed and examined additionally using 3-dimensional virtual embryoscopy. Results The different types of conjoined twins are summarized in a table for practical use during ultrasound examination. In evaluating conjoined twins, 2-dimensional ultrasound is the criterion standard. Three-dimensional and Doppler ultrasounds add anatomical and prognostic information. Virtual embryoscopy imaging reveals additional findings in our 3 cases not seen with routine 2-dimensionalultrasound examination. Conclusions Each case of conjoined twins is unique and should be evaluated with the best possible imaging techniques. Three-dimensional and Doppler ultrasound should be added to the systematic diagnostic evaluation of conjoined twins. Virtual embryoscopy imaging may contribute to earlier, more appropriate counseling and management of these pregnancies. Target Audience: Obstetricians and gynecologists, family physicians Learning Objectives: After completing this CME activity, physicians should be better able to differentiate between the different types of conjoined twins and their prognosis, compare the different imaging techniques used for the evaluation of conjoined twins to decide whether additional diagnostic imaging techniques are useful in an individual case, and evaluate complex cases, such as conjoined twins, using new imaging techniques.

Design and validation of a 3D virtual reality desktop system for sonographic length and volume measurements in early pregnancy evaluation

To design and validate a desktop virtual reality (VR) system, for presentation and assessment of volumetric data, based on commercially off‐the‐shelf hardware as an alternative to a fully immersive CAVE‐like I‐Space VR system.

First-Trimester Crown-Rump Length and Embryonic Volume of Fetuses with Structural Congenital Abnormalities Measured in Virtual Reality: An Observational Study

Background. With the introduction of three-dimensional (3D) ultrasound it has become possible to measure volumes. The relative increase in embryonic volume (EV) is much larger than that of the crown-rump length (CRL) over the same time period. We examined whether EV is a better parameter to determine growth restriction in fetuses with structural congenital abnormalities. Study Design, Subjects, and Outcome Measures. CRL and EV were measured using a Virtual Reality (VR) system in prospectively collected 3D ultrasound volumes of 56 fetuses diagnosed with structural congenital abnormalities in the first trimester of pregnancy (gestational age 7+5 to 14+5 weeks). Measured CRL and EV were converted to z-scores and to percentages of the expected mean using previously published reference curves of euploid fetuses. The one-sample t-test was performed to test significance. Results. The EV was smaller than expected for GA in fetuses with structural congenital abnormalities (−35%  p < 0.001, z-score −1.44  p < 0.001), whereas CRL was not (−6.43%  p = 0.118, z-score −0.43  p = 0.605). Conclusions. CRL is a less reliable parameter to determine growth restriction in fetuses with structural congenital abnormalities as compared with EV. By measuring EV, growth restriction in first-trimester fetuses with structural congenital abnormalities becomes more evident and enables an earlier detection of these cases.

Growth trajectories of the human embryonic head and periconceptional maternal conditions

STUDY QUESTION Can growth trajectories of the human embryonic head be created using 3D ultrasound (3D-US) and virtual reality (VR) technology, and be associated with second trimester fetal head size and periconceptional maternal conditions? SUMMARY ANSWER Serial first trimester head circumference (HC) and head volume (HV) measurements were used to create reliable growth trajectories of the embryonic head, which were significantly associated with fetal head size and periconceptional maternal smoking, age and ITALIC! in vitro fertilization (IVF)/intra-cytoplasmic sperm injection (ICSI) treatment. WHAT IS KNOWN ALREADY Fetal growth is influenced by periconceptional maternal conditions. STUDY DESIGN, SIZE, DURATION We selected 149 singleton pregnancies with a live born non-malformed fetus from the Rotterdam periconception cohort. PARTICIPANTS/MATERIALS, SETTING, METHODS Bi-parietal diameter and occipital frontal diameter to calculate HC, HV and crown-rump length (CRL) were measured weekly between 9 + 0 and 12 + 6 weeks gestational age (GA) using 3D-US and VR. Fetal HC was obtained from second trimester structural anomaly scans. Growth trajectories of the embryonic head were created with general additive models and linear mixed models were used to estimate associations with maternal periconceptional conditions as a function of GA and CRL, respectively. MAIN RESULTS A total of 303 3D-US images of 149 pregnancies were eligible for embryonic head measurements (intra-class correlation coefficients >0.99). Associations were found between embryonic HC and fetal HC ( ITALIC! ρ = 0.617, ITALIC! P < 0.001) and between embryonic HV and fetal HC ( ITALIC! ρ = 0.660, ITALIC! P < 0.001) in ITALIC! Z-scores. Maternal periconceptional smoking was associated with decreased, and maternal age and IVF/ICSI treatment with increased growth trajectories of the embryonic head measured by HC and HV (All ITALIC! P < 0.05). LIMITATIONS, REASONS FOR CAUTION The consequences of the small effect sizes for neurodevelopmental outcome need further investigation. As the study population consists largely of tertiary hospital patients, external validity should be studied in the general population. WIDER IMPLICATIONS OF THE FINDINGS Assessment of growth trajectories of the embryonic head may be of benefit in future early antenatal care. STUDY FUNDING/COMPETING INTERESTS This study was funded by the Department of Obstetrics and Gynaecology, Erasmus MC University Medical Centre and Sophia Foundation for Medical Research, Rotterdam, The Netherlands (SSWO grant number 644). No competing interests are declared.

First-trimester detection of surface abnormalities: A comparison of 2- and 3-dimensional ultrasound and 3-dimensional virtual reality ultrasound

The aim was to determine the diagnostic performance of 3-dimensional virtual reality ultrasound (3D_VR_US) and conventional 2- and 3-dimensional ultrasound (2D/3D_US) for first-trimester detection of structural abnormalities. Forty-eight first trimester cases (gold standard available, 22 normal, 26 abnormal) were evaluated offline using both techniques by 5 experienced, blinded sonographers. In each case, we analyzed whether each organ category was correctly indicated as normal or abnormal and whether the specific diagnosis was correctly made. Sensitivity in terms of normal or abnormal was comparable for both techniques (P = .24). The general sensitivity for specific diagnoses was 62.6% using 3D_VR_US and 52.2% using 2D/3D_US (P = .075). The 3D_VR_US more often correctly diagnosed skeleton/limb malformations (36.7% vs 10%; P = .013). Mean evaluation time in 3D_VR_US was 4:24 minutes and in 2D/3D_US 2:53 minutes (P < .001). General diagnostic performance of 3D_VR_US and 2D/3D_US apparently is comparable. Malformations of skeleton and limbs are more often detected using 3D_VR_US. Evaluation time is longer in 3D_VR_US.

First‐trimester hand measurements in euploid and aneuploid human fetuses using virtual reality

Although second‐trimester and third‐trimester reference curves for human fetal hand growth allow for identification of several genetic syndromes, little is known about first‐trimester hand growth. We investigated first‐trimester hand growth in euploid and aneuploid fetuses.

First-trimester diagnosis of thrombocytopenia-absent radius syndrome using virtual reality.

Introduction Thrombocytopenia-absent radius (TAR) syndrome is a rare condition characterized by hypomegakaryocytic thrombocytopenia and bilateral absence of the radius with presence of both thumbs. Thrombocytopenia is often symptomatic in the neonatal period and improves over time (Hall, 1987). A microdeletion of chromosome 1q21.1 is found in all investigated patients with TAR syndrome (Klopocki et al., 2007). However, the recessive inheritance pattern of TAR syndrome requires an additional causative allele that until recently was unknown. A low-frequency single-nucleotide polymorphism (SNP) in the RBM8A gene is detected as the second causative allele in the origination of TAR syndrome (Albers et al., 2012).

Differentiation of early first-trimester cranial neural tube defects

Neural tube defects (NTDs) are one of themost commonly reported birth defects and are the result of failure of primary neurulation, the folding and fusion of the neural plate1. We report on three early first-trimester cases with different types of cranial neural tube defects (NTD) not previously reported in ultrasound studies. Previously, it was believed that the process of neural tube closure occurred in a ‘zipper-like’ fashion, starting at one point and proceeding in both cranial and caudal directions. However, neural tube closure is a more complex process. More recently, Nakatsu et al. described three different closure initiation sites of the human neural tube after studying miscarried embryos2. Following from this closure model six different types of cranial NTDs were distinguished, based on location of the closure defect (Figure S1)2. Survival rates significantly decreased if the

Evaluation of First-Trimester Physiological Midgut Herniation Using Three-Dimensional Ultrasound

Introduction: The aim of this study was to investigate the development of midgut herniation in vivo using three-dimensional (3D) ultrasonographic volume and distance measurements and to create reference data for physiological midgut herniation in ongoing pregnancies in a tertiary hospital population. Materials and Methods: The transvaginal 3D ultrasound volumes of 112 women, seen weekly during the first trimester of pregnancy, were obtained and subsequently analysed in a virtual reality environment. The width of the umbilical cord insertion, the maximum diameter of the umbilical cord, and the volume of midgut herniation were measured from 6 until 13 weeks gestational age (GA). Results: All parameters had a positive relation with GA, crown-rump length, and abdominal circumference. In approximately 1 of 10 volumes no midgut herniation could be observed at 9 and 10 weeks GA. In 5.0% of the fetuses the presence of midgut herniation could still be visualised at 12 weeks GA. Conclusion: Reference charts for several dimensions of physiological midgut herniation were created. In the future, our data might be used as a reference in the first trimester for comparison in case of a suspected pathological omphalocele.