3D Ultrasound Scan Research Articles

Use of ultrasound imaging for the diagnosis of abnormal uterine bleeding in the bonnet macaque ( Macaca radiata).

Ultrasound is a powerful, low-cost, non-invasive medical tool used by laboratory animal veterinarians for diagnostic imaging. Sonohysterography and transvaginal ultrasound are frequently used to assess uterine anomalies in women presenting with abnormal uterine bleeding (AUB). In the present study, we have evaluated the abdominal ultrasound of bonnet monkeys ( n = 8) showing spontaneous ovulatory ( n = 5) and anovulatory ( n = 3) AUB. The ovulatory ( n = 5) macaques showed cyclic AUB for 7-8 days. The anovulatory ( n = 3) macaques had irregular AUB with menstrual cycles of 40-45 days. The B-mode abdominal, colour Doppler and 3D ultrasound scans were performed during the proliferative phase of the menstrual cycle. Ultrasound examination revealed endometrial polyps in five macaques and endometrial hyperplasia in three animals. The width and length of endometrial polyps was around 0.5-1 cm (average 0.51 ± 0.23 cm × 0.96 ± 0.16 cm) with significant increase in endometrial thickness ( P < 0.0002). 3D ultrasound also showed a homogeneous mass in the uterine cavity and colour Doppler ultrasound showed increased vascularity in the endometrial polyps. Endometrial hyperplasia characteristically appeared as a thickened echogenic endometrium ( P < 0.0002). This study demonstrates the use of non-invasive ultrasound techniques in the diagnosis of AUB in macaques.

Placental Location and Reproductive Outcome in Patients With Uterine Septum or Arcuate Uterus [19G

INTRODUCTION: The aim of this study is to determine placental location in pregnancy that ended in a live birth in patients with known uterine septum or arcuate uterine anomaly. METHODS: This retrospective study included sixty-seven patients who had a live birth and a diagnosis of uterine septum or arcuate uterine anomaly based on trans-vaginal 3D ultrasound scan (TV 3D US) with or without saline infusion sonohysterogram (SIH) between 2005 and 2015. Thirty patients (44.8%) presented with secondary infertility, 6 patients (9%) presented with recurrent pregnancy loss (RPL), 3 patients (4.5%) presented with history of miscarriage, and 28 (41.8%) presented with secondary infertility and miscarriage or RPL. RESULTS: Mean age was 32.4±4.3 years. Mean gestational age was 37.1±3.9 weeks. Placental location was not on the septum in 57 patients (85.1%); placental location was anterior in 29 patients (43.3%), posterior in 25 patients (37.3%), and lateral in 3 patients (4.5%). Eight patients (11.9%) had partial fundal location (fundal anterior in 6 patients [75%], and fundal posterior in 2 patients [25%]). Placental location was fundal in 2 patients (3%). In one of these patients the septum was found to be very vascular during hysteroscopy; the patient experienced vaginal bleeding through the pregnancy and delivered at 28 weeks. CONCLUSION: Our data support the long held theory that placental location in relation to uterine septum or arcuate uterine anomaly influence reproductive outcomes. Also, our data may explain the variable reproductive outcome of patients with such anomalies in the literature.

Cesarean Scar Hysterotomy: Assessment by Three-dimensional Transvaginal Ultrasound Scan

ABSTRACT Objective The combined study of two-dimensional (2D) and three-dimensional (3D) sonographic records may be useful to diagnose wound dehiscence from hysterotomy and forecast the well-being of future gestations. In that respect, irregular cicatrization patterns can be identified from the early puerperium over the whole postparturition recovery period, and may encourage the need for further cesarean in new pregnancies to come. Subjects and Methods A random sample of 42 female patients were subjected to transvaginal sonographic exploration at three sampling times, namely 4 days, 4 months, and 1 year following hysterotomy. All of these women recovered successfully from their cesarean and were discharged from hospital 5 days after parturition. The 2D and 3D surveys were subsequently undertaken at each of the three study times. Four days after surgery, the 2D ultrasound scan aimed at evaluating the early evolution of the uterine scar. On the contrary, 3D echographies were implemented frame-to-frame, in a transverse direction, from the right to left sides of the uterus. Results The 3D sonographic records from those dehiscent wounds displayed at this time a wide, irregular hypoechogenic area crossed over by linear structures representing the suture material (Vycril). Such a record was called a “shark bite” pattern. The latter puerperal dehiscence pattern persisted in the isthmic region for 4 months and 1 year after delivery. It consistently featured a notch between the scar borders that run perpendicular to the complete extent of the internal myometrium layer and bordered the anterior uterine wall. By considering the length of the hysterotomy-derived notch over the whole study period, two types of scars could be differentiated through 2D sonographic surveys, scar notches &gt;2/3 (n=9) or ≤1/3 (n=4) of the total scar lengt. Six of the 13 wound-dehiscent women monitored in this study became pregnant within 2 years after their former cesarean. All were subjected to a second hysterotomy, before which an in situ examination of the previous uterine scar could be made. Early puerperal ultrasound scan focusing on hypoechogenic areas across the borders of hysterotomy-derived scars under suturing pressure must be undertaken by means of 2D transvaginal ultrasound scan, with the bonus that such exploration can be extended through several months to a 1 year period after surgery. The extent of dehiscent myometrium areas and the depth of the notch remaining between the serose and the cervical channel of the stigma can be used as reliable indicators for defective cicatrization processes and should be used as background information aiding in future gestations. The 3D transvaginal ultrasound scan provides the practitioner with thorough records of myometrial failure and enhances the morphological study of iatrogenic pathologies originating from cesarean surgery. The state and extent of healed vs failing cicatrization areas can be easily assessed by means of 3D transvaginal ultrasound scan. How to cite this article Troyano JM, Clavijo MT, Martinez-Wallin I, Molina-Betancor A, Alvarez-de-la-Rosa M, Padilla AI, Bajo-Arenas J. Cesarean Scar Hysterotomy: Assessment by Three-dimensional Transvaginal Ultrasound Scan. Donald School J Ultrasound Obstet Gynecol 2017;11(1):82-87.

Playing Pregnancy: The Ludification and Gamification of Expectant Motherhood in Smartphone Apps

Like other forms of embodiment, pregnancy has increasingly become subject to representation and interpretation via digital technologies. Pregnancy and the unborn entity were largely private, and few people beyond the pregnant women herself had access to the foetus growing within her (Duden). Now pregnant and foetal bodies have become open to public portrayal and display (Lupton The Social Worlds of the Unborn). A plethora of online materials – websites depicting the unborn entity from the moment of conception, amateur YouTube videos of births, social media postings of ultrasounds and self-taken photos (‘selfies’) showing changes in pregnant bellies, and so on – now ensure the documentation of pregnant and unborn bodies in extensive detail, rendering them open to other people’s scrutiny. Other recent digital technologies directed at pregnancy include mobile software applications, or ‘apps’. In this article, we draw on our study involving a critical discourse analysis of a corpus of pregnancy-related apps offered in the two major app stores. In so doing, we discuss the ways in which pregnancy-related apps portray pregnant and unborn bodies. We place a particular focus on the ludification and gamification strategies employed to position pregnancy as a playful, creative and fulfilling experience that is frequently focused on consumption. As we will demonstrate, these strategies have wider implications for concepts of pregnant and foetal embodiment and subjectivity. It is important here to make a distinction between ludification and gamification. Ludification is a broader term than gamification. It is used in the academic literature on gaming (sometimes referred to as ‘ludology’) to refer to elements of games reaching into other aspects of life beyond leisure pursuits (Frissen et al. Playful Identities: The Ludification of Digital Media Cultures; Raessens). Frissen et al. (Frissen et al. "Homo Ludens 2.0: Play, Media and Identity") for example, claim that even serious pursuits such as work, politics, education and warfare have been subjected to ludification. They note that digital technologies in general tend to incorporate ludic dimensions. Gamification has been described as ‘the use of game design elements in non-game contexts’ (Deterding et al. 9). The term originated in the digital media industry to describe the incorporation of features into digital technologies that not explicitly designed as games, such as competition, badges, rewards and fun that engaged and motivated users to make them more enjoyable to use. Gamification is now often used in literatures on marketing strategies, persuasive computing or behaviour modification. It is an important element of ‘nudge’, an approach to behaviour change that involves persuasion over coercion (Jones, Pykett and Whitehead). Gamification thus differs from ludification in that the former involves applying ludic principles for reasons other than the pleasures of enjoying the game for their own sake, often to achieve objectives set by actors and agencies other than the gamer. Indeed, this is why gamification software has been described by Bogost (Bogost) as ‘exploitationware’.

Comparison between the findings on trans-vaginal 3D ultrasound scan and hysteroscopy in patients diagnosed with subtle incomplete uterine septum/arcuate uterine anomaly on hysteroscopy

To determine if there is discrepancy between the measurement of the mid fundal length of subtle incomplete uterine septum or arcuate uterine anomaly on hysteroscopy and on trans-vaginal 3D ultrasound scan (TV 3D US) with or without saline infusion sonohysterogram (SIH).

A 3D sparse motion field filtering for quantitative analysis of fascial layers mobility based on 3D ultrasound scans.

In the last few years, there has been an increasing interest in the role of deep fascia mobility in musculoskeletal dynamics and chronic pain mechanisms. In a previous paper we presented an innovative semiautomatic approach to evaluate the 3D motion of the fascia using ultrasound (US) imaging, generating a sparse deformation vector field. This paper presents an improvement of our original method, focusing on the filtering of the sparse vector field and its validation. Moreover, in order to evaluate the performance of the algorithm, a method is proposed to generate synthetic deformation vector fields, including: expansion, rotation, horizontal shear, and oblique shear components. Preliminary tests on the final synthetic deformation vector fields showed promising results. Further experiments are required in order to optimize the tuning of the algorithm.

A semiautomatic method for in vivo three-dimensional quantitative analysis of fascial layers mobility based on 3D ultrasound scans.

Recently, there has been an increasing interest in the role of deep fascia mobility in musculoskeletal dynamics and chronic pain mechanisms; however, no strategies have been presented so far to study in vivo fascial motion in 3D. This paper presents a semiautomatic method, based on ultrasound (US) imaging, enabling a 3D evaluation of fascia mobility. The proposed approach relies on the acquisition of 3D US datasets at rest and during a voluntary muscular contraction and consists of two phases: 3D US dataset analysis and generation of a displacement vector field using a block matching technique (Phase 1) and validation and filtering of the resulting displacement vector field for outliers removal (Phase 2). The accuracy and effectiveness of the proposed method were preliminarily tested on different 3D US datasets, undergoing either simulated (procedural) or real (muscular contraction) deformations. As for the simulated deformation, estimated displacement vectors resulting from Phase 1 presented a mean magnitude percentage error of 8.05 % and a mean angular error of 4.78° which, after Phase 2, were reduced by 69.44 and by 83.05 %, respectively. Tests on real deformations further validated the effectiveness of Phase 2 in the removal of outliers from the displacement vector field. Obtained results preliminarily demonstrate the viability of the proposed algorithm for the analysis of fascia mobility. Such analysis can enable clinicians to better understand the fascia role in musculoskeletal dynamics and disorder. Further experiments are needed to optimize the method in consideration of the anatomical region to be studied.

3D curvature of muscle fascicles in triceps surae.

Muscle fascicles curve along their length, with the curvatures occurring around regions of high intramuscular pressure, and are necessary for mechanical stability. Fascicles are typically considered to lie in fascicle planes that are the planes visualized during dissection or two-dimensional (2D) ultrasound scans. However, it has previously been predicted that fascicles must curve in three-dimensional (3D) and thus the fascicle planes may actually exist as 3D sheets. 3D fascicle curvatures have not been explored in human musculature. Furthermore, if the fascicles do not lie in 2D planes, then this has implications for architectural measures that are derived from 2D ultrasound scans. The purpose of this study was to quantify the 3D curvatures of the muscle fascicles and fascicle sheets within the triceps surae muscles and to test whether these curvatures varied among different contraction levels, muscle length, and regions within the muscle. Six male subjects were tested for three torque levels (0, 30, and 60% maximal voluntary contraction) and four ankle angles (-15, 0, 15, and 30° plantar flexion), and fascicles were imaged using 3D ultrasound techniques. The fascicle curvatures significantly increased at higher ankle torques and shorter muscle lengths. The fascicle sheet curvatures were of similar magnitude to the fascicle curvatures but did not vary between contractions. Fascicle curvatures were regionalized within each muscle with the curvature facing the deeper aponeuroses, and this indicates a greater intramuscular pressure in the deeper layers of muscles. Muscle architectural measures may be in error when using 2D images for complex geometries such as the soleus.

The influence of IVF/ICSI treatment on human embryonic growth trajectories.

Is in vitro fertilization treatment with or without intracytoplasmatic sperm injection (IVF/ICSI) associated with changes in first and second trimester embryonic and fetal growth trajectories and birthweight in singleton pregnancies? Embryonic and fetal growth trajectories and birthweight are not significantly different between pregnancies conceived with IVF/ICSI treatment and spontaneously conceived pregnancies with reliable pregnancy dating. IVF/ICSI treatment has been associated with increased risks of preterm birth, fetal growth restriction and low birthweight. Decreased first-trimester crown-rump length (CRL) in the general population has been inversely associated with the same adverse pregnancy outcomes. In a prospective periconception birth cohort study conducted in a tertiary centre, 146 singleton pregnancies with reliable pregnancy dating and nonmalformed live borns were investigated, comprised of 88 spontaneous and 58 IVF/ICSI pregnancies. Serial 3D ultrasound scans were performed from 6 to 12 weeks of gestation. As estimates of embryonic growth, CRL and embryonic volume (EV) were measured using the I-Space virtual reality system. General characteristics were obtained from self-administered questionnaires at enrolment. Fetal growth parameters at 20 weeks and birthweight were obtained from medical records. To assess associations between IVF/ICSI and embryonic growth trajectories, estimated fetal weight and birthweight, stepwise linear mixed model analyses and linear regression analyses were performed using square root transformed CRL and fourth root transformed EV. In 146 pregnancies, 934 ultrasound scans were performed of which 849 (90.9%) CRLs and 549 (58.8%) EVs could be measured. Embryonic growth trajectories were comparable between IVF/ICSI pregnancies and spontaneously conceived pregnancies (CRL: βIVF/ICSI = 0.10√mm; P = 0.10; EV: βIVF/ICSI = 0.03(4)√cm³; P = 0.13). Estimated fetal weight and birthweight were also comparable between both groups (βIVF/ICSI = 6 g; P = 0.36 and βIVF/ICSI = 80 g; P = 0.24, respectively). Variations in embryonic growth trajectories of spontaneously conceived pregnancies with reliable pregnancy dating may partially be a result of less precise pregnancy dating and differences in endometrium receptivity compared with IVF/ICSI pregnancies. The absence of a significant difference in embryonic and fetal growth trajectories suggests safety of IVF/ICSI treatment with regard to early embryonic growth. However, further research is warranted to ascertain the influence of IVF/ICSI treatments in a larger study population, and to estimate the impact of the underlying causes of the subfertility and other periconceptional exposures on human embryonic and fetal growth trajectories. This study was supported by the Department of Obstetrics and Gynaecology of the Erasmus MC, University Medical Centre. No competing interests are declared.

Double Ring Array Catheter for In Vivo Real-Time 3D Ultrasound

We developed new forward-viewing matrix transducers consisting of double ring arrays of 118 total PZT elements integrated into catheters used to deploy medical interventional devices. Our goal is 3D ultrasound guidance of medical device implantation to reduce x-ray fluoroscopy exposure. The double ring arrays were fabricated on inner and outer custom polyimide flexible circuits with inter-element spacing of 0.20 mm and then wrapped around an 11 French (Fr) catheter to produce a 15 Fr catheter (outer diameter [O.D.]). We used a braided cabling technology to connect the elements to the Volumetrics Medical Imaging (VMI) real-time 3D ultrasound scanner. Transducer performance yielded an average -6 dB fractional bandwidth of 49% ± 11% centered at 4.4 MHz for 118 elements. Real-time 3D cardiac scans of the in vivo pig model yielded good image quality including en face views of the tricuspid valve and real-time 3D guidance of an endo-myocardial biopsy catheter introduced into the left ventricle.

Patient-mounted Robot for 2D Ultrasound Probe Scanning using McKibben Artificial Muscles

Patient-mounted Robot for 2D Ultrasound Probe Scanning using McKibben Artificial Muscles

A 3D ultrasound scanning system for image guided liver interventions

Two-dimensional ultrasound (2D US) imaging is commonly used for diagnostic and intraoperative guidance of interventional liver procedures; however, 2D US lacks volumetric information that may benefit interventional procedures. Over the past decade, three-dimensional ultrasound (3D US) has been developed to provide the missing spatial information. 3D US image acquisition is mainly based on mechanical, electromagnetic, and freehand tracking of conventional 2D US transducers, or 2D array transducers available on high-end machines. These approaches share many problems during clinical use for interventional liver imaging due to lack of flexibility and compatibility with interventional equipment, limited field-of-view (FOV), and significant capital cost compared to the benefits they introduce. In this paper, a novel system for mechanical 3D US scanning is introduced to address these issues. The authors have developed a handheld mechanical 3D US system that incorporates mechanical translation and tilt sector sweeping of any standard 2D US transducer to acquire 3D images. Each mechanical scanning function can be operated independently or may be combined to allow for a hybrid wide FOV acquisition. The hybrid motion mode facilitates registration of other modalities (e.g., CT or MRI) to the intraoperative 3D US images by providing a larger FOV in which to acquire anatomical information. The tilting mechanism of the developed mover allows image acquisition in the intercostal rib space to avoid acoustic shadowing from bone. The geometric and volumetric scanning validity of the 3D US system was evaluated on tissue mimicking US phantoms for different modes of operation. Identical experiments were performed on a commercially available 3D US system for direct comparison. To replicate a clinical scenario, the authors evaluated their 3D US system by comparing it to CT for measurement of angle and distance between interventional needles in different configurations, similar to those used for percutaneous ablation of liver tumors. The mean geometrical hybrid 3D reconstruction error measured from scanning of a known string phantom was less than 1 mm in two directions and 2.5 mm in the scanning direction, which was comparable or better than the same measurements obtained from a commercially available 3D US system. The error in volume measurements of spherical phantom models depended on depth of the object. For a 20 cm(3) model at a depth of 15 cm, a standard depth for liver imaging, the mean error was 3.6% ± 4.5% comparable to the 2.3% ± 1.8% error for the 3D US commercial system. The error in 3D US measurement of the tip distance and angle between two microwave ablation antennas inserted into the phantom was 0.9 ± 0.5 mm and 1.1° ± 0.7°, respectively. A 3D US system with hybrid scanning motions for large field-of-view 3D abdominal imaging has been developed and validated. The superior spatial information provided by 3D US might enhance image-guidance for percutaneous interventional treatment of liver malignancies. The system has potential to be integrated with other liver procedures and has application in other abdominal organs such as kidneys, spleen, or adrenals.

3D ultrasound system to investigate intraventricular hemorrhage in preterm neonates

Intraventricular hemorrhage (IVH) is a common disorder among preterm neonates that is routinely diagnosed and monitored by 2D cranial ultrasound (US). The cerebral ventricles of patients with IVH often have a period of ventricular dilation (ventriculomegaly). This initial increase in ventricle size can either spontaneously resolve, which often shows clinically as a period of stabilization in ventricle size and eventual decline back towards a more normal size, or progressive ventricular dilation that does not stabilize and which may require interventional therapy to reduce symptoms relating to increased intracranial pressure. To improve the characterization of ventricle dilation, we developed a 3D US imaging system that can be used with a conventional clinical US scanner to image the ventricular system of preterm neonates at risk of ventriculomegaly. A motorized transducer housing was designed specifically for hand-held use inside an incubator using a transducer commonly used for cranial 2D US scans. This system was validated using geometric phantoms, US/MRI compatible ventricle volume phantoms, and patient images to determine 3D reconstruction accuracy and inter- and intra-observer volume estimation variability. 3D US geometric reconstruction was found to be accurate with an error of <0.2%. Measured volumes of a US/MRI compatible ventricle-like phantom were within 5% of gold standard water displacement measurements. Intra-class correlation for the three observers was 0.97, showing very high agreement between observers. The coefficient of variation was between 1.8–6.3% for repeated segmentations of the same patient. The minimum detectable difference was calculated to be 0.63 cm3 for a single observer. Results from ANOVA for three observers segmenting three patients of IVH grade II did not show any significant differences (p > 0.05) for the measured ventricle volumes between observers. This 3D US system can reliably produce 3D US images of the neonatal ventricular system. There is the potential to use this system to monitor the progression of ventriculomegaly over time in patients with IVH.

Effects of wall distensibility in hemodynamic simulations of an arteriovenous fistula

Arteriovenous fistulae are created surgically to provide adequate access for dialysis patients suffering from end-stage renal disease. It has long been hypothesized that the rapid blood vessel remodeling occurring after fistula creation is in part a process to restore the mechanical stresses to some preferred level, i.e., mechanical homeostasis. The current study presents fluid-structure interaction (FSI) simulations of a patient-specific model of a mature arteriovenous fistula reconstructed from 3D ultrasound scans. The FSI results are compared with previously published data of the same model but with rigid walls. Ultrasound-derived wall motion measurements are also used to validate the FSI simulations of the wall motion. Very large time-averaged shear stresses, 10-15 Pa, are calculated at the fistula anastomosis in the FSI simulations, values which are much larger than what is typically thought to be the normal homeostatic shear stress in the peripheral vasculature. Although this result is systematically lower by as much as 50% compared to the analogous rigid-walled simulations, the inclusion of distensible vessel walls in hemodynamic simulations does not reduce the high anastomotic shear stresses to "normal" values. Therefore, rigid-walled analyses may be acceptable for identifying high shear regions of arteriovenous fistulae.

Human Embryonic Growth and Development of the Cerebellum Using 3-Dimensional Ultrasound and Virtual Reality

The aim of our study was to evaluate the first trimester cerebellar growth and development using 2 different measuring techniques: 3-dimensional (3D) and virtual reality (VR) ultrasound visualization. The cerebellum measurements were related to gestational age (GA) and crown-rump length (CRL). Finally, the reproducibility of both the methods was tested. In a prospective cohort study, we collected 630 first trimester, serially obtained, 3D ultrasound scans of 112 uncomplicated pregnancies between 7 + 0 and 12 + 6 weeks of GA. Only scans with high-quality images of the fossa posterior were selected for the analysis. Measurements were performed offline in the coronal plane using 3D (4D view) and VR (V-Scope) software. The VR enables the observer to use all available dimensions in a data set by visualizing the volume as a "hologram." Total cerebellar diameter, left, and right hemispheric diameter, and thickness were measured using both the techniques. All measurements were performed 3 times and means were used in repeated measurements analysis. After exclusion criteria were applied 177 (28%) 3D data sets were available for further analysis. The median GA was 10 + 0 weeks and the median CRL was 31.4 mm (range: 5.2-79.0 mm). The cerebellar parameters could be measured from 7 gestational weeks onward. The total cerebellar diameter increased from 2.2 mm at 7 weeks of GA to 13.9 mm at 12 weeks of GA using VR and from 2.2 to 13.8 mm using 3D ultrasound. The reproducibility, established in a subset of 35 data sets, resulted in intraclass correlation coefficient values ≥0.98. It can be concluded that cerebellar measurements performed by the 2 methods proved to be reproducible and comparable with each other. However, VR-using all three dimensions-provides a superior method for the visualization of the cerebellum. The constructed reference values can be used to study normal and abnormal cerebellar growth and development.

Real-time 3D ultrasound imaging of infant tongue movements during breast-feeding

BackgroundWhether infants use suction or peristaltic tongue movements or a combination to extract milk during breast-feeding is controversial. The aims of this pilot study were 1] to evaluate the feasibility of using 3D ultrasound scanning to visualise infant tongue movements; and 2] to ascertain whether peristaltic tongue movements could be demonstrated during breast-feeding. Methods15 healthy term infants, aged 2weeks to 4months were scanned during breast-feeding, using a real-time 3D ultrasound system, with a 7MHz transducer placed sub-mentally. Results1] The method proved feasible, with 72% of bi-plane datasets and 56% of real-time 3D datasets providing adequate coverage [>75%] of the infant tongue. 2] Peristaltic tongue movement was observed in 13 of 15 infants [83%] from real-time or reformatted truly mid-sagittal views under 3D guidance. ConclusionsThis is the first study to demonstrate the feasibility of using 3D ultrasound to visualise infant tongue movements during breast-feeding. Peristaltic infant tongue movement was present in the majority of infants when the image plane was truly mid-sagittal but was not apparent if the image was slightly off the mid-sagittal plane. This should be considered in studies investigating the relative importance of vacuum and peristalsis for milk transfer.

Human embryonic growth trajectories and associations with fetal growth and birthweight

How do human embryonic growth trajectories evolve in the first trimester, and is first-trimester embryonic growth associated with fetal growth and birthweight (BW)? Human embryonic growth rates increase between 9 and 10 weeks of gestation and are associated with mid-pregnancy fetal growth and BW. 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. We recruited 201 pregnancies before 8 weeks of gestation in a prospective periconception cohort study conducted in a tertiary center. 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 Pearson's correlation coefficients. 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). This study was conducted in a tertiary hospital. Therefore, future studies in other populations are warranted to confirm our results. 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.

First trimester brain ventricle fluid and embryonic volumes measured by three-dimensional ultrasound with the use of I-Space virtual reality

Is it possible to evaluate first trimester brain ventricle development in human pregnancies using an innovative virtual reality (VR) application and to analyze the relation of the embryonic volume (EV) and brain ventricle fluid volume (BVFV) with gestational age (GA), crown-rump length (CRL) and the Carnegie stage? Volumetry and staging of the human embryo using a VR application make it possible to obtain unique information about in-vivo embryonic normal and abnormal development and about the sizes of the ventricles and body. Human brain development is complex and has a rapidly changing anatomy during the first trimester of pregnancy. New insights will enable early detection of cerebral pathology. In a prospective cohort study, we weekly performed three-dimensional (3D) ultrasound examinations in 112 uncomplicated pregnancies between 6 + 0 and 12 + 6 weeks GA. The examinations resulted in 696 3D ultrasound scans that were transferred to the I-Space VR system and analyzed using V-Scope volume rendering software. V-Scope is used to create a 'hologram' of the ultrasound image and allows depth perception and interaction with the rendered objects. The CRL measurements were performed with a tracing tool, and the volume measurements were automatically performed with a segmentation algorithm. The embryos were staged according to the internal and external characteristics of the Carnegie staging system. All longitudinal outcomes were analyzed using repeated measures ANOVA. CRL could be measured in 91% of the datasets and ranged from 2.5 to 79.0 mm. EV could be measured in 66% of the datasets and ranged from 2.4 to 23 812.0 mm&sup3;, whereas the BVFV could be measured in 38% of the datasets and ranged from 10.4 to 226.3 mm&sup3;. Finally, in 74% of the datasets, the embryos were staged according to the Carnegie criteria, starting as early as stage 12. Reference charts of volumes versus GA, CRL and stage were constructed. There was no significant relationship between the CRL or EV and the birthweight. The low success rate is a limitation of this study that can be explained mainly by non-targeted scanning of the embryonic head. The I-Space VR system and the V-Scope software enable automatic EV and BVFV measurements and 3D observations of embryonic development in the first trimester. This allows in-vivo staging of human embryos based on both internal and external morphological characteristics. None.

Strain Measurement of Abdominal Aortic Aneurysm with Real-time 3D Ultrasound Speckle Tracking

Abdominal aortic aneurysm rupture is caused by mechanical vascular tissue failure. Although mechanical properties within the aneurysm vary, currently available ultrasound methods assess only one cross-sectional segment of the aorta. This study aims to establish real-time 3-dimensional (3D) speckle tracking ultrasound to explore local displacement and strain parameters of the whole abdominal aortic aneurysm. Validation was performed on a silicone aneurysm model, perfused in a pulsatile artificial circulatory system. Wall motion of the silicone model was measured simultaneously with a commercial real-time 3D speckle tracking ultrasound system and either with laser-scan micrometry or with video photogrammetry. After validation, 3D ultrasound data were collected from abdominal aortic aneurysms of five patients and displacement and strain parameters were analysed. Displacement parameters measured in vitro by 3D ultrasound and laser scan micrometer or video analysis were significantly correlated at pulse pressures between 40 and 80 mmHg. Strong local differences in displacement and strain were identified within the aortic aneurysms of patients. Local wall strain of the whole abdominal aortic aneurysm can be analysed in vivo with real-time 3D ultrasound speckle tracking imaging, offering the prospect of individual non-invasive rupture risk analysis of abdominal aortic aneurysms.

Incomplete Restoration of Homeostatic Shear Stress Within Arteriovenous Fistulae

Arteriovenous fistulae are surgically created to provide adequate access for dialysis patients suffering from end-stage renal disease. It has long been hypothesized that the rapid blood vessel remodeling occurring after fistula creation is, in part, a process to restore the mechanical stresses to some preferred level, i.e., mechanical homeostasis. We present computational hemodynamic simulations in four patient-specific models of mature arteriovenous fistulae reconstructed from 3D ultrasound scans. Our results suggest that these mature fistulae have remodeled to return to ''normal'' shear stresses away from the anastomoses: about 1.0 Pa in the outflow veins and about 2.5 Pa in the inflow arteries. Large parts of the anastomoses were found to be under very high shear stresses >15 Pa, over most of the cardiac cycle. These results suggest that the remodeling process works toward restoring mechanical homeostasis in the fistulae, but that the process is limited or incomplete, even in mature fistulae, as evidenced by the elevated shear at or near the anastomoses. Based on the long term clinical viability of these dialysis accesses, we hypothesize that the elevated nonhomeostatic shear stresses in some portions of the vessels were not detrimental to fistula patency.