A. H. Koning

Visualization of postoperative anterior cruciate ligament reconstruction bone tunnels: Reliability of standard radiographs, CT scans, and 3D virtual reality images

Background and purpose Non-anatomic bone tunnel placement is the most common cause of a failed ACL reconstruction. Accurate and reproducible methods to visualize and document bone tunnel placement are therefore important. We evaluated the reliability of standard radiographs, CT scans, and a 3-dimensional (3D) virtual reality (VR) approach in visualizing and measuring ACL reconstruction bone tunnel placement. Methods 50 consecutive patients who underwent single-bundle ACL reconstructions were evaluated postoperatively by standard radiographs, CT scans, and 3D VR images. Tibial and femoral tunnel positions were measured by 2 observers using the traditional methods of Amis, Aglietti, Hoser, Stäubli, and the method of Benereau for the VR approach. Results The tunnel was visualized in 50–82% of the standard radiographs and in 100% of the CT scans and 3D VR images. Using the intraclass correlation coefficient (ICC), the inter- and intraobserver agreement was between 0.39 and 0.83 for the standard femoral and tibial radiographs. CT scans showed an ICC range of 0.49–0.76 for the inter- and intraobserver agreement. The agreement in 3D VR was almost perfect, with an ICC of 0.83 for the femur and 0.95 for the tibia. Interpretation CT scans and 3D VR images are more reliable in assessing postoperative bone tunnel placement following ACL reconstruction than standard radiographs.

Human embryonic growth trajectories and associations with fetal growth and birthweight

STUDY QUESTION How do human embryonic growth trajectories evolve in the first trimester, and is first-trimester embryonic growth associated with fetal growth and birthweight (BW)? SUMMARY ANSWER Human embryonic growth rates increase between 9 and 10 weeks of gestation and are associated with mid-pregnancy fetal growth and BW. WHAT IS KNOWN ALREADY Fetal growth is associated with health and disease risks in later life. Until recently, prenatal care and research have been focused predominantly on fetal growth in the second and third trimesters of pregnancy. Longitudinal first-trimester data remain scarce. STUDY DESIGN, SIZE, DURATION We recruited 201 pregnancies before 8 weeks of gestation in a prospective periconception cohort study conducted in a tertiary center. PARTICIPANTS/MATERIALS, SETTING, METHODS We performed weekly 3D ultrasound scans from enrollment up to 13 weeks of gestation. To create embryonic growth trajectories, serial crown-rump length (CRL) measurements were performed using the V-Scope software in the BARCO I-Space. Mid-pregnancy fetal growth parameters and BW were obtained from medical records. Z-scores were calculated for CRL, mid-pregnancy estimated fetal weight (EFW) and BW. Associations between embryonic and fetal growth parameters were investigated using Pearsons correlation coefficients. MAIN RESULTS AND THE ROLE OF CHANCE During the early first trimester (up to 9 weeks of gestation), we observed a constant absolute mean embryonic CRL growth rate of 0.99 mm/day (SD 0.10), while the relative growth rate decreased. Between 9 and 10 weeks of gestation, the absolute growth rate increased, and during late first trimester (from 10 weeks of gestation onward), we observed a constant mean relative growth rate of 4.1% (SD 0.006) per day. Overall, early and late first-trimester median CRL Z-scores were strongly correlated with mid-pregnancy EFW (r overall/early/late = 0.57/0.57/0.54, P < 0.001) but only overall and late CRL Z-scores were correlated with BW (r overall = 0.15, P = 0.04; r early = 0.10, P = 0.17; r late = 0.17, P = 0.02). LIMITATIONS, REASONS FOR CAUTION This study was conducted in a tertiary hospital. Therefore, future studies in other populations are warranted to confirm our results. WIDER IMPLICATIONS OF THE FINDINGS This study shows differences between early and late first-trimester embryonic growth coinciding with changes in intrauterine nourishment. The established associations between first-trimester embryonic growth and fetal size in mid-pregnancy and at birth emphasize that more research is warranted to establish the importance of these results for preconceptional and early pregnancy care.

Validation of a simple method for measuring cranial deformities (Plagiocephalometry)

Craniofacial measuring is essential for diagnosis or evaluation of growth and therapies. Skull deformities in children are mainly caused by craniosynostosis or by external pressure in positional skull deformations. Traditional anthropometry does not sufficiently analyze craniofacial shape. In computed tomography (CT) scanning, radiation loads are considerable. Both CT and magnetic resonance imaging (MRI) scanning require anaesthesia in children for accurate imaging, due to their long acquisition time. This makes CT and MRI unsuitable for long term follow-up of pediatric patients unless there is a compelling reason. Other noninvasive three-dimensional (3D) surface scanners still have limited practical use. Van Vlimmeren et al6 presented plagiocephalometry (PCM) as a simple and versatile instrument to quantify skull deformities with high intrarater and interrater reliability, but no comparison was made with the actual skull shape. At the Erasmus University Medical Center Rotterdam, Sophia Childrens Hospital PCM was compared to 3D-CT scanning in 21 children with craniosynostosis early in life. The PCM ring proved to fit closely to the skin with mean differences less than 1 mm (P < 0.05). The shape of the PCM ring was not significantly changed when taken off the head (P > 0.05). Finally, no significant differences are shown between measurements on the skull (CT-scan) and PCM ring off the head (P > 0.05). This study proves that PCM is a reliable method for analysis of skull deformities. The measurements are in agreement with 3D-CT scanning as golden standard. Although only 2-dimensional measurements are performed by PCM, the combination of simplicity, reliability, and validity make it a promising tool for daily practice.

Periconception maternal characteristics and embryonic growth trajectories: the Rotterdam Predict study

STUDY QUESTION Are maternal characteristics and lifestyle factors associated with human embryonic growth trajectories? SUMMARY ANSWER Periconception maternal age is associated with increased, and smoking and alcohol use with decreased embryonic growth trajectories, estimated with crown-rump length (CRL) measurements. WHAT IS KNOWN ALREADY Fetal weight is associated with health and disease in later life. Maternal characteristics and lifestyle factors affect fetal growth in the second and third trimesters of pregnancy and at birth; however, little is known about the association of these characteristics with first trimester embryonic growth. STUDY DESIGN, SIZE, DURATION In a tertiary centre, pregnant women were recruited and enrolled in a prospective periconception cohort study before 8 weeks of gestation. We selected 87 spontaneously conceived singleton pregnancies of women recruited in 2009 and 2010 that ended in non-malformed live births. PARTICIPANTS/MATERIALS, SETTING, METHODS We performed weekly three-dimensional ultrasound scans from enrolment up to 13 weeks of gestation. At enrolment, a questionnaire was completed. Embryonic CRL measurements were performed using the V-Scope software in the BARCO I-Space. Associations between maternal characteristics and embryonic growth were assessed using square root transformed CRL as response in linear mixed model analyses, adjusted for potential confounders. MAIN RESULTS AND THE ROLE OF CHANCE Four hundred and ninety-six scans from 87 pregnancies were included. In the multivariable analysis, maternal age was positively associated with first trimester CRL (difference per maternal year of age 0.024√mm (95% confidence interval (CI) 0.009, 0.040), P = 0.001). At 6 and 12 weeks of gestation, the CRL of an embryo from a 40-year-old mother was estimated 2.0 mm (61%) and 7.2 mm (14%) larger, respectively, compared with an embryo from a 20-year-old mother. Smoking of 10 or more cigarettes per day was negatively associated with CRL (difference -0.211√mm (95% CI -0.416, -0.006), P = 0.04), with embryos that were 0.9 mm (18.7%) and 3.1 mm (5.5%) smaller at 6 and 12 weeks, respectively, compared with non-smokers. Periconception alcohol use was negatively associated with CRL growth rate (difference -0.0025√mm (95% CI -0.0047, -0.0003)/day gestational age, P = 0.022), with embryos that were 0.2 mm (3%) and 1.1 mm (2%) smaller at 6 and 12 weeks, respectively, compared with non-alcohol users. Parity, BMI and moment of initiation of folic acid use were not significantly associated with embryonic CRL. LIMITATIONS, REASONS FOR CAUTION Due to the selection of pregnancies in a tertiary centre and the small number of pregnancies, the external validity of the results has to be confirmed using larger sample sizes and other population-based periconception cohort studies. WIDER IMPLICATIONS OF THE FINDINGS The association of maternal age and smoking with embryonic growth is in line with previous literature, whereas the association between embryonic growth and alcohol use is a new finding. However, concerning exposure to alcohol, the effect estimate was small and it is questionable whether this is of clinical value. More research is warranted to unravel underlying mechanisms and to assess the implications for preconception and early pregnancy care, such as the development and implementation of effective lifestyle interventions. STUDY FUNDING/COMPETING INTEREST(S) The work was funded by the Department of Obstetrics and Gynaecology, Erasmus MC, University Medical Centre, Rotterdam, The Netherlands. The authors declare no conflicts of interest.

A virtual reality rendition of a fetal meningomyelocele at 32 weeks of gestation

Using a virtual reality system to render images obtained with three-dimensional (3D) ultrasound a fetal lumbosacral meningomyelocele (L3–S2) is shown here at 32 weeks’ gestation (Figure 1). The defect was originally observed in a 24-year-old primigravida during a routine sonogram at 22 weeks (Figure 2). After extensive counseling the patient decided not to have an amniocentesis and to continue with the pregnancy. In this image the meningomyelocele is seen from a coronal view with the sac partially ‘cut open’. The slitlike dark structure in the center is the actual midline defect of the osseous structure of the spine. The spinal nerve roots can be observed running from the vertebral column towards the inside wall of the meningomyelocele where they adhere to the neural placode (Figure 3). The neural placode is the flat plate of dysplastic neural tissue, which is elevated to the dome of the meningomyelocele by the pressure of cerebrospinal fluid. The image, originally obtained during a 3D ultrasound examination, is seen hovering in space in front of the investigator, giving the impression of a 3D structure with a diameter of approximately 80 × 80 × 60 cm. The image can be moved, resized and turned around in space with the help of a hand-held joystick. The joystick also allows a part of the volume to be ‘cut away’.

Embryonic delay in growth and development related to confined placental trisomy 16 mosaicism, diagnosed by I-Space Virtual Reality

OBJECTIVE To demonstrate the use of a novel three-dimensional (3D) virtual reality (VR) system in the visualization of first trimester growth and development in a case of confined placental trisomy 16 mosaicism (CPM+16). DESIGN Case report. SETTING Prospective study on first trimester growth using a 3D VR system. PATIENT(S) A 34-year-old gravida 1, para 0 was seen weekly in the first trimester for 3D ultrasound examinations. INTERVENTION(S) Chorionic villus sampling was performed because of an enlarged nuchal translucency (NT) measurement and low pregnancy-associated plasma protein-A levels, followed by amniocentesis. RESULT(S) Amniocentesis revealed a CPM+16. On two-dimensional (2D) and 3D ultrasound no structural anomalies were found with normal fetal Dopplers. Growth remained below the 2.3 percentile. At 37 weeks, a female child of 2010 g (<2.5 percentile) was born. After birth, growth climbed to the 50th percentile in the first 2 months. CONCLUSION(S) The I-Space VR system provided information about phenotypes not obtainable by standard 2D ultrasound. In this case, the delay in growth and development could be observed very early in pregnancy. Since first trimester screening programs are still improving and becoming even more important, systems such as the I-Space open a new era for in vivo studies on the physiologic and pathologic processes involved in embryogenesis.

Vasculogenesis and Angiogenesis in the First Trimester Human Placenta: An Innovative 3D Study Using an Immersive Virtual Reality System

First trimester human villous vascularization is mainly studied by conventional two-dimensional (2D) microscopy. With this (2D) technique it is not possible to observe the spatial arrangement of the haemangioblastic cords and vessels, transition of cords into vessels and the transition of vasculogenesis to angiogenesis. The Confocal Laser Scanning Microscopy (CLSM) allows for a three-dimensional (3D) reconstruction of images of early pregnancy villous vascularization. These 3D reconstructions, however, are normally analyzed on a 2D medium, lacking depth perception. We performed a descriptive morphologic study, using an immersive Virtual Reality system to utilize the full third dimension completely. This innovative 3D technique visualizes 3D datasets as enlarged 3D holograms and provided detailed insight in the spatial arrangement of first trimester villous vascularization, the beginning of lumen formation within various junctions of haemangioblastic cords between 5 and 7 weeks gestational age and in the gradual transition of vasculogenesis to angiogenesis. This innovative immersive Virtual Reality system enables new perspectives for vascular research and will be implemented for future investigation.

Gestational sac fluid volume measurements in virtual reality

To evaluate a virtual reality (VR) application for gestational sac fluid volume (GSFV) measurements in first‐trimester pregnancies and to study the correlation between different embryonic growth parameters.

Internal carotid dissection after Le Fort III distraction in Apert syndrome: A case report

A 10-year-old girl with Apert syndrome underwent a Le Fort III osteotomy with the positioning of internal and external distraction devices. The operation was straightforward with no intraoperative complications. Very soon after completion of surgery an anisocoria (unilateral dilation of a pupil) was noticed. This was followed by intracranial oedema which was fatal. The aetiology was dissection of the right internal carotid artery is reported. The complications of Le Fort osteotomies are discussed regarding patients with complex syndromal craniosynostosis and midface hypoplasia, such as Apert syndrome.

First trimester umbilical cord and vitelline duct measurements using virtual reality

BACKGROUND the umbilical cord and vitelline duct are of vital importance to the fetus, but they are rarely the subject of first trimester two-dimensional (2D) ultrasound evaluation due to the complexity of their shape and morphology. Virtual reality (VR) allows efficient visualisation and measurement of complex structures like the umbilical cord and vitelline duct. AIM to measure normal first trimester human growth of the umbilical cord length (UCL) and vitelline duct length (VDL) using a VR system; and to correlate both measurements with the gestational age (GA) and crown-rump length (CRL) and the VDL with the yolk sac volume (YSV). STUDY DESIGN prospective cohort study. Serial three-dimensional (3D) ultrasound measurements were performed from six to 14weeks GA, resulting in 125 3D volumes. These volumes were analysed using an I-Space VR system. SUBJECTS Thirty-two healthy pregnant women with an ongoing, normal pregnancy. OUTCOME MEASURES the UCL, VDL, YSV and other related structures were measured. RESULTS The UCL, measurable in 55% of cases, was positively correlated to advancing GA and CRL (p<0.001). The VDL could be measured in 42% of cases and showed a positive relationship with GA and CRL (p<0.001). There was a significant (p<0.001) relationship between YSV and VDL. CONCLUSIONS the present study, facilitated by a VR system, is the first to provide an in-vivo longitudinal description of normal first trimester growth of the human umbilical cord and vitelline duct. Further studies will reveal whether these parameters can be used in detection of abnormal fetal development.