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Introduction: The emergence of handheld ultrasound devices capable of connecting to cell phones or tablets heralds a significant advancement in medical technology, particularly within the field of obstetrics. These devices offer the promise of immediate bedside ultrasound examinations, potentially revolutionizing patient care by enabling fetal assessments in diverse settings., Material and Methods: This prospective study aimed to validate the reliability of non-piezo, chip-based handheld ultrasound devices in clinical obstetric practice. Conducted in a university hospital obstetric ward, the study included 100 pregnant women between 17 and 41 weeks of gestation. Participants underwent ultrasound examinations using both conventional and portable point-of-care ultrasound (POCUS) devices to compare the accuracy in estimating fetal weight and other parameters, such as cardiac activity, fetal presentation, placental location, and amniotic fluid volume. The reliability and agreement between the devices were assessed using intraclass correlation coefficients, Bland-Altman plots, and Pearson correlation coefficients., Results: The results show a near-perfect agreement (0.98) and correlation (r = 0.98, p < 0.001) for estimated fetal weight and most biometry measurements between the two types of ultrasound devices, with slight deviations in head circumference and amniotic fluid index measurements. Subgroup analysis revealed variations in agreement and correlation rates with higher BMI and advanced gestational age, indicating areas for further refinement., Conclusions: These findings affirm the high reliability of handheld ultrasound devices for basic obstetric ultrasound evaluations, supporting their integration into daily clinical practice. This technology improves the flexibility and immediacy of prenatal care, although further research is needed to optimize its application across patient populations and treatment settings., (© 2024 The Author(s). Acta Obstetricia et Gynecologica Scandinavica published by John Wiley & Sons Ltd on behalf of Nordic Federation of Societies of Obstetrics and Gynecology (NFOG).)

Importance: Accurate assessment of gestational age (GA) is essential to good pregnancy care but often requires ultrasonography, which may not be available in low-resource settings. This study developed a deep learning artificial intelligence (AI) model to estimate GA from blind ultrasonography sweeps and incorporated it into the software of a low-cost, battery-powered device., Objective: To evaluate GA estimation accuracy of an AI-enabled ultrasonography tool when used by novice users with no prior training in sonography., Design, Setting, and Participants: This prospective diagnostic accuracy study enrolled 400 individuals with viable, single, nonanomalous, first-trimester pregnancies in Lusaka, Zambia, and Chapel Hill, North Carolina. Credentialed sonographers established the "ground truth" GA via transvaginal crown-rump length measurement. At random follow-up visits throughout gestation, including a primary evaluation window from 14 0/7 weeks' to 27 6/7 weeks' gestation, novice users obtained blind sweeps of the maternal abdomen using the AI-enabled device (index test) and credentialed sonographers performed fetal biometry with a high-specification machine (study standard)., Main Outcomes and Measures: The primary outcome was the mean absolute error (MAE) of the index test and study standard, which was calculated by comparing each method's estimate to the previously established GA and considered equivalent if the difference fell within a prespecified margin of ±2 days., Results: In the primary evaluation window, the AI-enabled device met criteria for equivalence to the study standard, with an MAE (SE) of 3.2 (0.1) days vs 3.0 (0.1) days (difference, 0.2 days [95% CI, -0.1 to 0.5]). Additionally, the percentage of assessments within 7 days of the ground truth GA was comparable (90.7% for the index test vs 92.5% for the study standard). Performance was consistent in prespecified subgroups, including the Zambia and North Carolina cohorts and those with high body mass index., Conclusions and Relevance: Between 14 and 27 weeks' gestation, novice users with no prior training in ultrasonography estimated GA as accurately with the low-cost, point-of-care AI tool as credentialed sonographers performing standard biometry on high-specification machines. These findings have immediate implications for obstetrical care in low-resource settings, advancing the World Health Organization goal of ultrasonography estimation of GA for all pregnant people., Trial Registration: ClinicalTrials.gov Identifier: NCT05433519.

Objective: To evaluate the accuracy of two portable ultrasound machines (PUM) in assessing fetal biometry and estimated gestational age (EGA)., Methods: This was a secondary analysis of data from the Fetal Age Machine Learning Initiative, an observational study of pregnant women in the USA and Zambia. Each participant underwent ultrasound assessment by an experienced sonographer using both a high-specification ultrasound machine (HSUM) and a PUM (Butterfly iQ or Clarius C3) to measure fetal biometry and calculate EGA at each visit. By comparing paired PUM and HSUM scans, we estimated agreement between individual biometry measurements and aggregate gestational age estimates by reporting mean difference, intraclass correlation coefficient (ICC) and Bland-Altman plots, adjusting for trend., Results: Between April and December 2021, 818 participants contributed 1386 paired PUM-HSUM ultrasound investigations, of which 991 PUM scans were obtained using the Butterfly iQ device and 395 using the Clarius C3 device. Gestational age at scan ranged from 7 to 38 weeks. Compared with HSUM, the Butterfly iQ PUM had a mean difference of -0.20 (95% CI, -0.60 to 0.20) days in the first trimester and -0.68 (95% CI, -0.93 to -0.44) days in the second/third trimesters. Compared with HSUM, the Clarius C3 PUM had a mean difference of -0.47 (95% CI, -1.11 to 0.18) days in the first trimester and -1.67 (95% CI, -2.10 to -1.25) days in the second/third trimesters. ICCs were 0.989 or greater throughout. Increasing gestational age was associated with increasing error and absolute error in EGA and fetal biometry. Both PUM devices demonstrated a modest trend toward underestimation of EGA with advancing gestational age in second/third-trimester scans, compared with HSUM., Conclusion: The Butterfly iQ and Clarius C3 PUM devices were highly accurate in performing fetal biometry in a diverse population from the USA and Zambia. © 2023 International Society of Ultrasound in Obstetrics and Gynecology., (© 2023 International Society of Ultrasound in Obstetrics and Gynecology.)

Background: Ethiopia is a low-income country located in the horn of Africa's sub-Saharan region, with very high incidences of maternal and neonatal mortality. Quality antenatal care improves perinatal health outcomes. The USAID funded Transform: Primary Health Care Activity in collaboration with the Ministry of Health and GE Healthcare introduced Vscan limited obstetric ultrasound services in 120 health centers in Ethiopia. So far, the experiences and opinions of midwives on their use have not been explored and described within the local context. This study therefore aims to explore and describe the experiences and opinions of midwives on Vscan limited obstetric ultrasound services at health centers within Ethiopia., Methods: An exploratory and descriptive qualitative study was conducted in Amhara, Oromia, and Southern Nations, Nationalities and Peoples' (SNNP) regions of Ethiopia. Twenty-four participants were selected through a purposeful sampling technique. In-depth individual interviews with trained midwives with practical hands-on limited obstetric ultrasound service provision experience were conducted. The thematic analysis was conducted manually., Results: The qualitative data analysis on the experiences and opinions of midwives revealed three themes, namely: individual perception of self-efficacy, facilitators, and barriers of limited obstetric ultrasound services. The basic ultrasound training, which was unique in its organization and arrangement, prepared and built the self-efficacy of trainees in executing their expected competencies. Support of health systems and health managers in dedicating space, availing essential supplies, and assigning human resources emerged as facilitators of the initiated limited obstetric ultrasound services, whereas high workload on one or two ultrasound trained midwives, interruption of essential supplies like paper towels, gel, and alternative power sources were identified as barriers for limited ultrasound services., Conclusion: This study explored the experiences and opinions of midwives who were trained on the provision of limited obstetric ultrasound services and served the community in health centers in rural parts of Ethiopia. The results of this study revealed the positive impacts of the intervention on the perceived self-efficacy, facilitation, and breaking-down of barriers to obstetric ultrasound services. Before scaling-up limited obstetric ultrasound interventions, health managers should ensure and commit to availing essential supplies (e.g., paper towels, ultrasound gel, and large memory hard discs), arranging private rooms, and training other mid-level health professionals. In addition, improving pregnant women's literacy on the national schedule for ultrasound scanning services is recommended., (© 2022. The Author(s).)

Objective: Advances in artificial intelligence (AI) have demonstrated potential to improve medical diagnosis. We piloted the end-to-end automation of the mid-trimester screening ultrasound scan using AI-enabled tools., Methods: A prospective method comparison study was conducted. Participants had both standard and AI-assisted US scans performed. The AI tools automated image acquisition, biometric measurement, and report production. A feedback survey captured the sonographers' perceptions of scanning., Results: Twenty-three subjects were studied. The average time saving per scan was 7.62 min (34.7%) with the AI-assisted method (p < 0.0001). There was no difference in reporting time. There were no clinically significant differences in biometric measurements between the two methods. The AI tools saved a satisfactory view in 93% of the cases (four core views only), and 73% for the full 13 views, compared to 98% for both using the manual scan. Survey responses suggest that the AI tools helped sonographers to concentrate on image interpretation by removing disruptive tasks., Conclusion: Separating freehand scanning from image capture and measurement resulted in a faster scan and altered workflow. Removing repetitive tasks may allow more attention to be directed identifying fetal malformation. Further work is required to improve the image plane detection algorithm for use in real time., (© 2021 The Authors. Prenatal Diagnosis published by John Wiley & Sons Ltd.)

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2)-associated infection (COVID-19) is affecting populations worldwide. This statement may serve as guidance for infection prevention and safe ultrasound practices during the COVID-19 pandemic. Ultrasound examination is a fundamental part of obstetric care, yet it is a potential vector for transmission of SARS-CoV-2. Decontamination methods should always be implemented for ultrasound equipment, especially in the presence of suspected or confirmed COVID-19 cases. There must be workflow policies to protect pregnant women and healthcare providers from nosocomial cross transmission of SARS-CoV-2. Cleaning and disinfecting of equipment must be in accordance with their potential of pathogen transmission. Consider using telemedicine and genetic technologies as an adjunctive of obstetric ultrasound to reduce patient crowding. Patient triage and education of healthcare providers of infection prevention are crucial to minimize cross contamination of SARS-CoV-2 during obstetric ultrasound.

Recent surveys have shown widespread lapses in the procedures used to reduce the risk of transmitting infection via medical devices. Transvaginal ultrasound examination has the potential to transmit vaginal infections, including human papillomavirus. Areas of particular concern are the use of probe covers with high rates of leakage, disinfectants that are not effective against human papillomavirus, and coupling gel from multiple-use containers. We reviewed these issues, and we recommend 4 steps to reduce the risk of transmitting infection. First, during every transvaginal ultrasound exam, the probe should be covered with a sterile, single-use "viral barrier" cover or a condom. Second, sterile, single-use ultrasound gel packets should be used. Third, after every examination, the probe should be cleaned to remove any visible gel or debris. Finally, after cleaning, the probe should undergo high-level disinfection using an agent with proven efficacy against the human papillomavirus, including hydrogen peroxide, hypochlorite, or peracetic acid. Glutaraldehyde, orthophthalaldehyde, phenols, and isopropyl alcohol have virtually no efficacy against the human papillomavirus., (Copyright © 2020. Published by Elsevier Inc.)

Background: Fetal and neonatal studies report a wide range of cardiac parameters derived by pulsed-wave Doppler tissue imaging (DTI) and two-dimensional speckle-tracking echocardiographic (STE) imaging. The use of different ultrasound systems and their vendor-specific software compromises the ability to compare echocardiographic findings among various studies. The aim of this study was to evaluate intervendor reproducibility as well as intra- and interobserver repeatability of DTI and STE measurements in normal-term fetuses and neonates., Methods: A prospective study was conducted of term fetuses (n = 196) from uncomplicated pregnancies assessed days before the onset of labor and a few hours after birth. Fetal and neonatal DTI and STE parameters were obtained and analyzed using vendor-specific software on three ultrasound systems: Toshiba Aplio MX versus GE Vivid E9 and GE Vivid E9 versus Philips EPIQ. A reproducibility study in fetuses and neonates (n = 118) was performed by systematic scanning with head-to-head comparison., Results: DTI reproducibility showed moderate to good correlation, with good agreement for fetuses and neonates on Toshiba versus GE (intraclass correlation coefficient [ICC] = 0.4-0.8). Correlation of DTI measurements on GE versus Philips was poor to moderate for fetuses (ICC = 0.1-0.6) and moderate to good for neonates (ICC = 0.5-0.8), with wider limits of agreement. Fetal and neonatal STE parameters revealed very poor correlation (ICC = 0.1-0.3) and agreement among ultrasound vendors. Intra- and interobserver repeatability demonstrated good to excellent correlation of all fetal and neonatal DTI and STE measurements, with good agreement irrespective of the ultrasound platform used., Conclusions: These findings demonstrate reliable assessment of fetal and neonatal DTI and STE measurements when performed on the same ultrasound platform, whereas ultrasound machines and software from different vendors give significantly divergent estimates of DTI and STE parameters in fetuses and neonates. These intervendor discrepancies have significant clinical and research implications and should be considered when interpreting and comparing study findings, establishing reference standards, or performing systematic reviews., (Crown Copyright © 2019. Published by Elsevier Inc. All rights reserved.)

Objective: The aim of this study was to evaluate the association between umbilical arterial pH and fetal vertebral artery Doppler velocimetry waveforms measured at the beginning of the second stage of labor in physiological term pregnancies. Methods: This was a prospective cohort study of 250 pregnancies. The resistance index, pulsatility index, and peak systolic velocity were measured. The relationship between the fetal Doppler and the umbilical arterial pH was evaluated. A simple linear regression and a general linear model were used to explore possible correlations of Doppler parameters with fetal and neonatal outcome adjusted for confundents. Results: Umbilical arterial pH values were directly associated with vertebral artery pulsatility index. Fetuses with lower pulsatility index values were at increased risk of a subsequent diagnosis of pathological fetal heart rate tracing patterns (presence of decelerations or reduced variability according to FIGO criteria during the second stage of labor). We estimated a decrease in pulsatility index of 10% in those fetuses destined to show a pathological fetal heart rate tracing. Conclusion: Vertebral artery Doppler waveforms correlates with umbilical pH in normal pregnancies and is also a function of fetal heart rate patterns. If this proportional association would be demonstrated also for abnormal pH values, vertebral artery pulsatility index might be useful to evaluate fetal wellbeing in those cases of suspected hypoxia/academia.

Objective To understand the impact of the measurement method to predict actual birthweight in pregnancies complicated with isolated polyhydramnios in the third trimester. Methods A prospective study was conducted with 60 pregnant women between the 37th and 40th weeks of gestation. Routine biometric measurements were obtained by two-dimensional (2D) ultrasonography. When a satisfactory image was obtained, the image was frozen to get two measurements. First, calipers were placed to get the manual measurement. Then automated measurement was captured by the ultrasonography machine in the same image. The fetal weight was estimated by using the Hadlock II formula. Results The mean difference was found to be 0.03, -0.77, -0.02 and 0.17 for biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC) and femur length (FL), respectively. Pearson's correlation coefficient between automated and manual estimated fetal weights (EFWs) and the actual birthweight was 0.919 and 0.796, respectively. The mean difference between actual and manual EFW measurement values was 46.16 ± 363.81 g (range between -745 g and 685 g) (P = 0.330). Also, the mean difference between actual and automated EFW measurement values was found to be 31.98 ± 218.65 g (range between -378 g and 742 g) (P = 0.262). The Bland-Altman test results have shown that, 666 g lower or 759 g higher values were obtained when the measurement was performed manually. On the other hand, EFW results were 396 g lower or 460 g higher than the actual birthweight with automated measurement tools. Conclusion The accuracy rate of fetal weight estimation with ultrasonography is high for both automated and manual measurements. Automated tools have a higher success to predict the EFW.

Objective: The "Fetal Brain Tutor 4us" (FBTApp) is a recently developed application for interactive multiplanar navigation through the normal fetal brain. The purpose of this work was to assess its impact on normal anatomy learning., Methods: A multiple-choice quiz (MCQ) was administered to first-year resident doctors in Obstetrics and Gynecology in two separate sessions, before and 2 weeks after downloading the FBTApp. For each MCQ, the junior trainee was asked to use one out of five items to label a specific cerebral structure on an ultrasound image of a normal midtrimester fetal brain. Six sonographic images of the fetal brain on each of the three scanning planes (axial, sagittal, and coronal) were shown to the participants at either session. The results of the two sessions were analysed and compared., Results: Overall, 216 questions were administered to the trainees in the 2-week study, 108 before and 108 after the use of the FBTApp. From the first to the second sessions, a significant increase of correct answers was noted (from 47/108 or 43% to 77/108 or 71%, P < 0.01). Particularly, a better improvement was obtained in the correct labelling of cerebral structures on the nonaxial (from 32% to 67%, +35%) vs axial (from 67% to 81%, +14%) view planes of the brain (P < 0.01)., Conclusion: The use of FBTApp seems capable to improve the knowledge of the normal fetal brain anatomy in subjects naive to dedicated prenatal ultrasound. This improvement seems greater on nonaxial planes., (© 2019 John Wiley & Sons, Ltd.)

We investigated how accurately low-cost ultrasound devices can estimate gestational age (GA) using both the standard plane and the obstetric sweep protocol (OSP). The OSP can be taught to health care workers without prior knowledge of ultrasound within one day and thus avoid the need to train dedicated sonographers. Three low-cost ultrasound devices were compared with one high-end ultrasound device. GA was estimated with the head circumference (HC), abdominal circumference (AC) and femur length (FL) using both the standard plane and the OSP. The results revealed that the HC, AC and FL can be used to estimate GA using low-cost ultrasound devices in the standard plane within the inter-observer variability presented in the literature. The OSP can be used to estimate GA by measuring the HC and the AC, but not the FL. This study shows that it is feasible to estimate GA in resource-limited countries with low-cost ultrasound devices using the OSP. This makes it possible to estimate GA and assess fetal growth for pregnant women in rural areas of resource-limited countries., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Objectives: To determine the feasibility of a telerobotic approach to remotely perform prenatal sonographic examinations., Methods: Thirty participants were prospectively recruited. Participants underwent a limited examination (assessing biometry, placental location, and amniotic fluid; n = 20) or a detailed examination (biometry, placental location, amniotic fluid, and fetal anatomic survey; n = 10) performed with a conventional ultrasound system. This examination was followed by an equivalent examination performed with a telerobotic ultrasound system, which enabled sonographers to remotely control all ultrasound settings and fine movements of the ultrasound transducer from a distance. Telerobotic images were read independently from conventional images., Results: The mean gestational age ± SD of the 30 participants was 22.9 ± 5.3 weeks. Paired-sample t tests showed no statistically significant difference between conventional and telerobotic measurements of fetal head circumference, biparietal diameter, or single deepest vertical pocket of amniotic fluid; however, a small but statistically significant difference was observed in measurements of abdominal circumference and femur length (P < .05). Intraclass correlations showed excellent agreement (>0.90) between telerobotic and conventional measurements of all 4 biometric parameters. Of 21 fetal structures included in the anatomic survey, 80% of the structures attempted across all patients were sufficiently visualized by the telerobotic system (range, 57%-100% per patient). Ninety-seven percent of patients strongly or somewhat agreed that they would be willing to have another telerobotic examination in the future., Conclusions: A telerobotic approach is feasible for remotely performing prenatal sonographic examinations. Telerobotic sonography (robotic telesonography) may allow for the development of satellite ultrasound clinics in rural, remote, or low-volume communities, thereby increasing access to prenatal imaging in underserved communities., (© 2018 by the American Institute of Ultrasound in Medicine.)

Purpose: Cervical assessment during digital vaginal examination (DVE) includes assessing cervical dilatation, effacement, position and consistency. Only cervical dilatation during labor has been previously researched. We investigated cervical changes, including cervical dilatation and effacement, using a wireless ultrasound (US) device., Materials and Methods: This was a longitudinal study investigating cervical changes during labor using a wireless US device. Twenty-five women in labor participated in a serial comparison of cervical dilatation, length and thickness measured during intrapartum transperineal sonography using a wireless mobile US device (SONON) with measurements of cervical dilatation and effacement obtained during serial DVEs., Results: Intrapartum sonography showed strong correlation with DVE in assessing cervical changes during labor including the measurement of cervical dilatation and thickness (p < .001). The failure rate of cervical length image collection was high; therefore, we could not determine the correlation between cervical length and effacement., Conclusions: We developed a new technique for evaluating effacement with cervical thickness. Cervical dilation and thickness using a transperineal intrapartum US demonstrated significant correlation with DVE findings. The use of a wireless US device is convenient and may be advantageous in the labor ward; however, further research is needed to define the role of this wireless device.

Background: Fetal cardiovascular magnetic resonance (CMR) imaging may provide a valuable adjunct to fetal echocardiography in the evaluation of congenital cardiovascular pathologies. However, dynamic fetal CMR is difficult due to the lack of direct in-utero cardiac gating. The aim of this study was to investigate the effectiveness of a newly developed Doppler ultrasound (DUS) device in humans for fetal CMR gating., Methods: Fifteen fetuses (gestational age 30-39 weeks) were examined using 1.5 T CMR scanners at three different imaging sites. A newly developed CMR-compatible DUS device was used to generate gating signals from fetal cardiac motion. Gated dynamic balanced steady-state free precession images were acquired in 4-chamber and short-axis cardiac views. Gating signals during data acquisition were analyzed with respect to trigger variability and sensitivity. Image quality was assessed by measuring endocardial blurring (EB) and by image evaluation using a 4-point scale. Left ventricular (LV) volumetry was performed using the single-plane ellipsoid model., Results: Gating signals from the fetal heart were detected with a variability of 26 ± 22 ms and a sensitivity of trigger detection of 96 ± 4%. EB was 2.9 ± 0.6 pixels (4-chamber) and 2.5 ± 0.1 pixels (short axis). Image quality scores were 3.6 ± 0.6 (overall), 3.4 ± 0.7 (mitral valve), 3.4 ± 0.7 (foramen ovale), 3.6 ± 0.7 (atrial septum), 3.7 ± 0.5 (papillary muscles), 3.8 ± 0.4 (differentiation myocardium/lumen), 3.7 ± 0.5 (differentiation myocardium/lung), and 3.9 ± 0.4 (systolic myocardial thickening). Inter-observer agreement for the scores was moderate to very good (kappa 0.57-0.84) for all structures. LV volumetry revealed mean values of 2.8 ± 1.2 ml (end-diastolic volume), 0.9 ± 0.4 ml (end systolic volume), 1.9 ± 0.8 ml (stroke volume), and 69.1 ± 8.4% (ejection fraction)., Conclusion: High-quality dynamic fetal CMR was successfully performed using a newly developed DUS device for direct fetal cardiac gating. This technique has the potential to improve the utility of fetal CMR in the evaluation of congenital pathologies.

Introduction: We aimed to test the reproducibility of head-perineum distance (HPD) measurements using two different ultrasound devices and five examiners, to compare ultrasound measurements and clinical assessments and to study if ultrasound examinations were acceptable for women in labor., Material and Methods: A reproducibility study was performed at Lund University Hospital, Sweden and Landspitali University Hospital, Iceland from February 2015 to February 2017. The study population comprised 40 healthy women in labor. HPD was measured with three replicate measurements from each woman with two different ultrasound devices, and the measurements were compared with clinical assessments. Acceptability was tested with a visual analog scale (VAS), and the mean VAS score from both ultrasound devices was compared with the VAS score from clinical palpation., Results: The median time interval between start of examinations with devices was 10 min (range 1-26 min). The intra-observer repeatability coefficient was 4.3 mm and the intraclass correlation coefficient was 0.97 (95% CI 0.95-0.98). The intraclass correlation coefficient between the two devices was 0.86 (95% CI 0.74-0.93) and limits of agreement were -9.6 mm to 16.6 mm. However, we observed a significant mean HPD difference between devices (3.5 mm; 95% CI 1.4-5.6 mm). Clinical assessments and the mean measurements of HPD were correlated (r = 0.64, p < 0.01). We found significant differences in acceptability in favor of ultrasound. The mean VAS score for both ultrasound devices was 2.0 vs. 4.1 for clinical examination (p < 0.01)., Conclusion: We found excellent intra-observer repeatability, good correlation but significant difference between devices. Women reported less discomfort with ultrasound than with clinical examinations., (© 2017 Nordic Federation of Societies of Obstetrics and Gynecology.)

Objectives: To investigate if the thermal index for bone (TIB) displayed on screen is an adequate predictor for the derated spatial-peak temporal-average (I SPTA .3 ) and spatial-peak pulse-average (I SPPA .3 ) acoustic intensities in a selection of clinical diagnostic ultrasound machines and transducers., Methods: We calibrated five clinical diagnostic ultrasound scanners and 10 transducers, using two-dimensional grayscale, color Doppler and pulsed-wave Doppler, both close to and far from the transducer, with a TIB between 0.1 and 4.0, recording 103 unique measurements. Acoustic measurements were performed in a bespoke three-axis computer-controlled scanning tank, using a 200-μm-diameter calibrated needle hydrophone., Results: There was significant but poor correlation between the acoustic intensities and the on-screen TIB. At a TIB of 0.1, the I SPTA .3 range was 0.51-50.49 mW/cm 2 and the I SPPA .3 range was 0.01-207.29 W/cm 2 . At a TIB of 1.1, the I SPTA .3 range was 19.02-309.44 mW/cm 2 and the I SPPA .3 range was 3.87-51.89 W/cm 2 ., Conclusions: TIB is a poor predictor for I SPTA .3 and I SPPA .3 and for the potential bioeffects of clinical diagnostic ultrasound scanners. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd., (Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.)

Purpose  To quantify the pressure exerted on the maternal abdominal wall during ultrasound examination and evaluate its effect on the fetal middle cerebral artery (MCA) peak systolic velocity (PSV). Materials and Method  Gravid women with singleton pregnancies in their 2nd-3 rd trimester undergoing fetal sonographic evaluation for various indications were recruited. Each subject underwent transabdominal US measuring fetal distance from the probe, abdominal thickness, amniotic fluid index and biophysical profile. The applied pressure was measured simultaneously using an electronic pressure sensor attached directly to the US probe. For each subject baseline values of the pressure required for proper visualization were obtained. Fetal MCA was then demonstrated using color Doppler US. The PSV was measured at different pressure ranges with each subject used as her own control. Care was taken not to exceed the baseline pressure for each subject. Results  29 women were recruited. 24 subjects (82.7 %) demonstrated a statistically significant positive correlation between the pressure exerted and MCA-PSV (R-0.37, p < 0.0001). Of these, 4 subjects (13.8 % of study population) demonstrated elevation of PSV values above 1.29 MOM and 5 subjects (17.2 %) demonstrated elevation of PSV values above 1.5 MOM for gestational age with increasing pressure. In total, 9 subjects (31 %) demonstrated significant changes in the MCA-PSV measurements (owing to increase in pressure applied) that could potentially falsely influence clinical obstetric diagnosis and management. Conclusion  The pressure exerted on the maternal abdominal wall during US examination is an important parameter, producing clinically significant measurable changes in fetal MCA hemodynamics. Further study is needed in order to demonstrate the potential effect of pressure as a parameter influencing the diagnostic accuracy of the MCA-PSV in the setting of fetal anemia., (© Georg Thieme Verlag KG Stuttgart · New York.)

Fetoscopic laser coagulation of the placental communicating vessels has become the standard treatment for monochorionic/diamniotic twin pregnancies complicated by severe twin-twin transfusion syndrome. Fetoscopic trocar placement can be performed with transabdominal ultrasound guidance with a posterior placenta and most anterior placentas that have a safe avascular window for entry. However, trocar insertion is challenging in cases of a complete anterior placenta without an avascular window. Current techniques to deal with this situation include mini-laparotomy with exteriorization to allow for dorsal entry, percutaneous lateral entry under transabdominal ultrasound/Doppler guidance, and laparoscopic assisted access with direct visualization of trocar entry. We describe a modified technique of laparoscopic assisted fetoscopic trocar placement using a laparoscopic ultrasound probe, which allows for precise, real-time guidance of trocar placement., (© 2015 S. Karger AG, Basel.)

Objective: To compare non-invasive hemodynamic measurements obtained in pregnant and postpartum women using two automated cardiac output monitors against those obtained by two-dimensional (2D) transthoracic echocardiography (TTE)., Methods: This was a cross-comparison study into which we recruited 114 healthy women, either with normal singleton pregnancy (across all three trimesters) or within 72 hours following delivery. Cardiac output estimations were obtained non-invasively using two different monitors, Ultrasound Cardiac Output Monitor (USCOM®, which uses continuous-wave Doppler analysis of transaortic blood flow) and Non-Invasive Cardiac Output Monitor (NICOM®, which uses thoracic bioreactance), and 2D-TTE. The performance of each monitor was assessed relative to that of TTE by calculating bias, precision, 95% limits of agreement and mean percentage difference (MPD). Intraobserver repeatability was assessed for both monitors and interobserver reproducibility was assessed for USCOM, NICOM being operator-independent., Results: Following exclusions due to poor-quality results of a monitor or TTE, or for medical reasons, our analysis included 98 women (29 in the first trimester, 25 in the second and 21 in the third, and 23 postpartum). For cardiac output estimation, when compared with TTE, USCOM had a bias ranging from 0.4 to 0.9 L/min. The MPD of USCOM was 29% in the third-trimester cohort. NICOM had a bias ranging from -1.0 to 0.6 L/min, with a MPD of 32% in the third-trimester group. There was limited agreement between the cardiac output monitors and TTE in the first and second trimesters, with a MPD of 38% for USCOM in both first and second trimesters, and 71% and 61% for NICOM in first and second trimesters, respectively. For cardiac output estimation using USCOM, we found excellent intraobserver repeatability (intraclass correlation coefficient (ICC), 0.97; 95% CI, 0.95-0.98) and interobserver reproducibility (ICC, 0.90; 95% CI, 0.81-0.94), and the repeatability for NICOM was comparable (ICC, 0.95; 95% CI, 0.93-0.97)., Conclusions: We found good agreement of both USCOM and NICOM when compared with 2D-TTE, specifically in the third trimester of pregnancy. Both devices had good intraobserver repeatability and either had good interobserver reproducibility or were operator-independent. Future studies should take into account the significant differences in the precise maternal hemodynamic values obtained by these devices, and consider developing device-specific reference ranges in pregnancy and the postpartum period. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd., (Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.)

Purpose: The objective of this study was to design and validate a "Tele-Operated UltRasound System" ("TOURS") to perform ultrasound examinations on patients located in isolated areas., Materials and Methods: A commercially available portable echograph was modified to allow functions (Doppler, two-dimensional, three-dimensional, elastography, etc.) and settings (gain, depth, freeze, record, etc.) to be teleoperated through an Internet connection. Specialized probes were developed that contained motorized transducers that could be teleoperated to change the transducer orientation. The system was installed and tested in four medical centers 50 km, 60 km, 1,800 km, and 7,000 km away from the university hospital., Results: Using the teleoperated system, 100 examinations were performed on the abdomen and pelvis (36%), vascular structures (42%), and small parts (thyroid and muscle, 22%), and 15 were performed on fetuses. During these examinations the expert sonographer was able to teleoperate the echograph and motorized probe to obtain images of sufficient quality for diagnoses in 97% of the cases. The average time for one examination was 17 ± 4 min. This new system (dimensions of 400 cm(3) and weighing 430 g) was found to be more ergonomic that a robotic arm previously developed by us for tele-echography (dimensions of 35 × 40 × 40 cm(3) and weighing 3-4 kg). In addition, the teleoperation of the echograph settings and functions allowed for greater ease in acquiring images, resulting in faster examinations with improved quality images., Conclusions: The results of this study demonstrate that the teleoperated echograph and probe system developed by our research group can be successfully used for ultrasound examinations in areas isolated from trained sonographers.

Objective: The objective was to determine if the need for transvaginal ultrasonographic examination can be decreased by the addition of the transabdominal high-frequency, 12-4-MHz linear transducer after a failed examination with the 6-2-mHz curvilinear transducer when evaluating for an intrauterine pregnancy (IUP)., Methods: This is a prospective pilot study of women in their first trimester of pregnancy presenting to the emergency department with abdominal pain and/or vaginal bleeding. If no IUP was identified using the curvilinear transducer via the transabdominal approach, they were subsequently scanned using the linear transducer. Patients without evidence of an IUP transabdominally were scanned via the transvaginal approach., Results: Eighty-one patients were evaluated; no IUP was visualized in 27 using the standard curvilinear transducer approach, and these then had an ultrasonography performed with the linear transducer. Of these, 9 patients (33.3%; 0.95 confidence interval [CO], 15.5%-51.1%) were found to have an IUP with the linear transducer. For the 18 patients who received a transvaginal scan, 15 patients (83.3%; 0.95 CI, 66.1%-100%) had no IUP identified with the transvaginal transducer, and 3 (16.7%; 0.95 CI, 0%-33.9%) had an IUP identified., Conclusions: The transabdominal use of a high-frequency linear transducer in the evaluation of patients in the first trimester after failed curvilinear transducer results in a clinically significant reduction in the need for transvaginal ultrasonography to confirm the presence of an IUP., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Aims: To enable scientific studies on fetal movements and its relation to fetal heart rate directly detecting fetal chest motion with ultrasonic Doppler method., Methods: A prototype of an ultrasonic Doppler fetal actocardiograph (ACG) was designed and handmade by the author. A 2 MHz ultrasound fetal heart rate (FHR) monitor was remodeled to detect fetal heartbeat and chest movement Doppler signals with a single ultrasound probe. The fetal movement Doppler signal was 20-50 Hz using 2 MHz ultrasound, separated from the fetal heartbeat Doppler signal, which was 100 or more Hz and sent to the autocorrelation FHR meter to record FHR curve, while fetal movement Doppler signals were detected through 20-80 Hz band-pass filter, and changed to spikes recorded on a cardiotocography chart., Results: The spike amplitudes of a moving steel ball expressed fetal movement on the ACG. FHR acceleration synchronized with fetal movement bursts. Fetal resting and active states are separated using the ACG. Fetal hiccupping movements on ACG were regular continuous spikes with 2-3 s intervals., Conclusion: Fetal movements and hiccups were correctly recorded with the FHR curve. The relation of FHR and movement will be further clarified in future ACG readings., (© 2015 Japan Society of Obstetrics and Gynecology.)

Objective: To assess whether subpubic arch angle (SPA) measurement before labor onset can predict labor outcome among low-risk pregnant women., Methods: 3D ultrasound volume was transperineally acquired from a series of nulliparous women with uncomplicated pregnancy at term before the onset of labor. SPA was measured offline using Oblique View Extended Imaging (OVIX) on each volume performed by an investigator not involved in the clinical management. Labor outcome was prospectively investigated in the whole study group., Results: Overall, 145 women were enrolled in the study. Of these, 83 underwent spontaneous vaginal delivery, whereas obstetric intervention was performed in 62 cases (Cesarean section in 40 and vacuum extraction in 22). The SPA appeared to be significantly narrower in the women submitted to obstetric intervention compared with those undergoing spontaneous vaginal delivery (116.8 ± 10.3° vs. 123.7 ± 9.6°, p < 0.01). At multivariate analysis SPA and maternal age were identified as independent predictors of the mode of delivery. On the other hand, the duration of labor did not show a significant relationship with SPA., Conclusions: In low-risk nulliparous women at term gestation, SPA measurement obtained by 3D ultrasound before the onset of labor seems to predict the likelihood of an obstetric intervention but not the duration of labor., (© 2015 S. Karger AG, Basel.)

Introduction: Recent studies have reported variations of up to 30% between different ultrasound machines for tissue Doppler imaging (TDI), a problem that can significantly impact clinical diagnosis, patient management and research studies. The objective of this study was to assess repeatability and agreement between fetal myocardial peak velocities evaluated by TDI with two different ultrasound systems., Materials and Methods: Systolic (S'), early (E') and late (A') diastolic myocardial peak velocities at mitral and tricuspid annuli as well as at the basal septum were evaluated by spectral TDI in 150 fetuses using two different ultrasound systems: Siemens Antares (Siemens Medical Systems, Malvern, Pa., USA) and Vivid Q (General Electric Healthcare, Horten, Norway). A method comparison study was performed, calculating intraclass correlation coefficients (ICC), and agreement was assessed by Bland-Altman plots., Results: Annular peak velocities showed lower values when measured by Vivid Q compared to values measured by Siemens Antares. ICC ranged from 0.07 (septal S') to 0.33 (right A'), showing very poor repeatability for clinical application. Agreement between the two systems was also poor, with high coefficients of variation for all measurements., Conclusions: Fetal annular peak velocities obtained with different ultrasound systems are not directly comparable. This is consistent with previous data in adults and warrants the need of system-specific reference values, suggesting that the same ultrasound machine should be used for longitudinal follow-up., (© 2015 S. Karger AG, Basel.)

Objectives: UmbiFlow™ is a mobile-connected Doppler device that utilises a continuous waveform to measure resistance in the umbilical artery. The main aim of this pilot study was to determine whether the use of UmbiFlow™ for umbilical artery Doppler in patients with a suspected decreased symphysis fundal (SF) growth could safely lead to a decreased number of patients requiring referral to a more specialised level of care. A secondary aim of the study was to evaluate the effectiveness of UmbiFlow™ Doppler as a screening tool for concealed placental insufficiency in late bookers by using a single screening cut-off value that will be abnormal for any gestation >28 weeks., Methods: The cohort comprised two groups of patients: The first group included all follow-up patients with suspected intra-uterine growth restriction (a decreased symphysis-fundus measurement based on serial assessment) who underwent on-site UmbiFlow™Doppler testing performed by the midwife directly after the clinical examination. The second group included late bookers, where gestation was uncertain; but estimated >28 weeks based on clinical grounds. This group was comprised of unselected patients who report to antenatal care late for the first time and received an UmbiFlow™Doppler test for concealed placental insufficiency., Results: UmbiFlow™Doppler could reduce the number of false referrals to hospital by 55%. A single UmbiFlow™Doppler test in late bookers appeared to identify a group of women at moderate risk of lower birth weight babies.

Purpose: This study was designed to compare nasal bone length (NBL) measurements using a manual multiplanar mode with those made using a newer semi-automatic technique (Volume NT™) acquired by an experienced operator as well as measurements done by two independent observers with different levels of ultrasound experience (conventional 2 D vs. Volume NT™)., Materials and Methods: Ultrasound examination was performed prospectively on 81 pregnant women with a singleton pregnancy at the time of their routine mid-trimester ultrasound scan., Results: The correct mid-sagittal plane of the fetal profile was successfully obtained using the semi-automatic technique in 53 of 81 cases., Conclusion: NBL measurements using conventional two-dimensional techniques showed significantly higher inter-observer variability than the semi-automatic program. Our study shows the feasibility of using a semi-automatic technique, especially for less experienced operators. Measurements obtained with the semi-automatic technique produced much less variable results around a mean than those obtained with conventional two-dimensional ultrasound., (© Georg Thieme Verlag KG Stuttgart · New York.)

Aim: To determine the applicability of pocket ultrasound as a complementary method for clinical evaluation during the first trimester of pregnancy., Material and Methods: A prospective cross-sectional study was conducted with 86 pregnant women attended in an emergency. The same operator performed the first examination with pocket device Vscan (General Electric, Vingmed Ultrasound, Horten, Norway) and then repeated the exam using a traditional handset high resolution Voluson 730 Expert (General Electric Healthcare Ultrasound, Milwaukee, WI, USA). Data were recorded with individual diagnoses by means of yes/no binary as the visualization of variables: gestational sac, embryo, embryo heartbeat, topical or ectopic pregnancy. Concordance was calculated using the kappa coefficient with its respective 95% confidential intervals (CI)., Results: There was no disagreement between the methods when compared the pocket and conventional ultrasounds. The best comparative result between the devices was as the visualization of the embryo heartbeat with kappa coefficient of 0.84 (95% CI 0.76 to 0.89). However, the pocket ultrasound had a low correlation for diagnosis of ectopic pregnancy, with kappa coefficient of -0.02 (95% CI -0.23 to 0.19). The smaller structure visualized and studied using the pocket ultrasound was an embryo of 3.4 mm., Conclusions: The method of pocket ultrasound has the potential to become a complementary and easy access for diagnostic tool in obstetric patients during the first trimester. However, in ectopic pregnancy cases the diagnosis should be realized by conventional ultrasound.

Objective: Ultrasound is considered a safe imaging modality and is routinely applied during early pregnancy. However, reservations are expressed concerning the application of Doppler ultrasound in early pregnancy due to energy emission of the ultrasound probe and its conversion to heat. The objective of this study was to evaluate the thermal effects of emitted Doppler ultrasound of different ultrasound machines and probes by means of temperature increase of in-vitro test-media., Methods: We investigated the energy-output of 5 vaginal and abdominal probes of 3 ultrasound machines (GE Healthcare, Siemens, Aloka). Two in-vitro test objects were developed at the Center for Medical Physics and Biomedical Engineering, Medical University Vienna (water bath and hydrogel bath). Temperature increase during Doppler ultrasound emission was measured via thermal sensors, which were placed inside the test objects or on the probes' surface. Each probe was emitting for 5 minutes into the absorbing test object with 3 different TI/MI settings in Spectral Doppler mode., Results: During water bath test, temperature increase varied between 0.1 and 1.0°C, depending on probe, setting and focus, and was found highest for spectral Doppler mode alone. Maximum temperature increase was found during the surface heating test, where values up to 2.4°C could be measured within 5 minutes of emission., Conclusions: Activation of Doppler ultrasound in the waterbath model causes a significant increase of temperature within one minute. Thermally induced effects on the embryo cannot be excluded when using Doppler ultrasound in early pregnancy.

The objective of this study was to assess the ability of different parameters to identify fetuses requiring neonatal care for coarctation of the aorta (CoA). Between January 2003 and December 2012, 175 fetuses referred for great vessel disproportion were divided into two groups: group A (n = 51) with high risk of CoA and delivery planned in tertiary care referral center and group B (n = 124) with no increased risk of CoA. In group A, diagnosis of CoA was confirmed in 38/51 (74 %). In group B, 2/124 had CoA. Multiple logistic regression analysis identified the best combination as diffusely hypoplastic and/or angular aortic arches, ventricular septal defect and aortic valve diameter <5 mm at 36-week gestational age (GA). Positive predictive value was 75 % when vessel disproportion was noted before 28-week GA and 73 % in the third trimester. Postnatal diagnosis involved 38 cases of CoA which had not been referred. One case of CoA diagnosed after birth was referred prenatally for difficulty of screening without any defect. The results of our prospective study are in agreement with those of previous series, but our false positive rate was lower especially when the diagnosis of vascular disproportion was made at third trimester. The performance of fetal cardiac screening does not seem to be very good, but prenatal diagnosis is probably not always possible: Among our three false negative cases, two had isolated vascular disproportion and the third no risk factors.

Background: Antenatal care is of core importance for maternal and child health and is therefore a central aspect of mother and child health care. One of the main goals of effective screening in antenatal care is the detection of suboptimal fetal growth. However, the sensitivity of antenatal diagnostic of suboptimal fetal growth (i.e. intrauterine growth restriction; IUGR) through clinical routine fetal ultrasonography has been observed to be low. A study conducted in Germany found that only 30% of IUGR cases and 40% of congenital malformations were diagnosed antenatally. Reasons for this low detection rate remain unclear., Methods/design: In the first of two study components, all mothers who delivered or will deliver a small for gestational age (SGA) newborn in one of three hospitals in Bremen (Germany) during recruitment phase are eligible for inclusion in a hospital based case-control study. Cases are defined as neonates with an IUGR that was not detected antenatally, while controls are defined as neonates whose IUGR was identified or at least suspected antenatally. Data collection instruments include a newborn documentation sheet, a standardized, computer-assisted personal interview with mothers, and a copy of pregnancy record books. The second component is a survey among all private practice-based gynecologists in the federal states of Bremen and Lower Saxony. The aim of this survey was to obtain detailed information e.g. on quality of ultrasonography equipment and examiner's ultrasonography experience and qualification level., Discussion: To our knowledge, this is one of the few German studies explicitly addressing care-related as well as maternal-related factors influencing the (non-) detection of IUGR by conducting comprehensive interviews with mothers and private practice-based gynecologists. Over the last 15 years there have been substantial technological advances in ultrasonography equipment in gynecological practices; hence there is the need to evaluate whether the detection rates of IUGR in Germany are still as low as previously reported in the late 1990ies. Our study results will contribute to a better understanding of core risk factors for low early detection rates of intrauterine growth restrictions and may support quality development in this important health care sector.

Objectives: To evaluate the application of a pocket-sized ultrasound machine (PUM) in a routine antenatal third-trimester scan compared with a high-specification ultrasound machine (HSUM)., Methods: This was an observational cohort study of 53 unselected women who came for their routine third-trimester ultrasound scan. The first scan was performed by an experienced ultrasonographer on an HSUM for fetal growth, fetal wellbeing and placental location. A second experienced operator performed the measurements on the PUM. Both operators were blinded to the other's findings and measurement results., Results: Fifty-one patients were eligible and scanned at a median gestational age of 31 + 1 (range, 27 + 2 to 36 + 0) weeks. Mean pregestational body mass index was 22.9 ± 3.1 (range, 17.6-35.7) kg/m(2) . In the comparison between measurements made using the PUM and HSUM, perfect agreement was found for fetal position, fetal bladder and stomach visualization (all κ 1.0) and very good agreement was found for placental position (κ 0.86). Measurements of deepest vertical pocket correlated moderately (intraclass correlation coefficient (ICC) 0.38 (95% CI, 0.12-0.59); Bland-Altman bias, 2.43 (95% limits of agreement (LoA), -22.65 to 27.51)). For fetal growth measurements there was very good agreement for biparietal diameter (ICC, 0.93 (95% CI, 0.88-0.96), Bland-Altman bias, -1.06 (95% LoA, -5.07 to 2.95)), and good agreement for femur length (ICC, 0.66 (95% CI, 0.48-0.79), Bland-Altman bias 0.56 (95% LoA, -5.97 to 7.08)) and transcerebellar diameter (ICC, 0.65 (95% CI, 0.46-0.78), Bland-Altman bias, -0.84 (95% LoA, -7.77 to 6.09))., Conclusion: A battery-driven PUM can be used in third-trimester obstetrics for routine assessment of fetal growth (biparietal diameter, transcerebellar diameter and femur length) and for assessment of fetal wellbeing., (Copyright © 2013 ISUOG. Published by John Wiley & Sons Ltd.)

Technological innovations accompanying advances in medicine have given rise to the possibility of obtaining better-defined fetal images that assist in medical diagnosis and contribute toward genetic counseling offered to parents during the prenatal period. In this article, we show our innovative experience of diagnosing fetal malformations through correlating 3-dimensional ultrasonography, magnetic resonance imaging, and computed tomography, which are accurate techniques for fetal assessment, with a fetal image reconstruction technique to create physical fetal models.

To meet the challenges of providing affordable, efficient ultrasound training, a low-cost, portable personal ultrasound training simulator with structured curriculums and integrated assessment methods has been developed. By using extended image volumes for training, the realistic experience of scanning over a larger body surface is emulated.

The X6-1 xmatrix array transducer allows a completely new approach to the diagnostic ultrasound: it permits visualization of fetal heart in real time, without the need for gating, and it is unaffected by motion artefacts. It is obtained in real time, without any spatial reconstruction. The authors compared this technology with the traditional one in two case reports: a diagnostic doubt of small muscular ventricular septal defect was solved using this new technique; a diagnosis of complete atrioventricular septal defect was confirmed. Three-dimensional real-time imaging would seem very precise in the study of fetal heart: the defects were fully visualized from any angulations. This new technology is promising but from the authors' limited experience, there is no evidence to use it in routine practice. It should be very useful to commence a prospective study on fetuses at risk while testing the superiority of this technique.

Background: Foetal echocardiography has been used to diagnose congenital heart disease. However, conventional echocardiography can only display two-dimensional (2D) structural images of the intricate three-dimensional (3D) foetal heart., Aim: The purpose of this study was to report the first use of a new transabdominal xMATRIX array transducer and to describe its ability to perform all 3D modalities: intelligent spatiotemporal image correlation (iSTIC) acquisition, xPlane imaging and 3D surface imaging., Methods: Eighty foetuses without congenital heart disease were included consecutively, with a gestational age between 20 and 37 weeks. 2D and 3D scans were performed with a transabdominal xMATRIX array transducer. Cardiac-STIC volume datasets were acquired and postprocessed with new automatic software (the 'Fetal Heart Navigator')., Results: A total of 224 iSTIC acquisitions were performed (mean time for each, 2 seconds). Only 78 iSTIC acquisitions (35%) were able to detect the ductal arch automatically. 'Fetal Heart Navigator' feasibility varied according to foetal position, including the descending aorta. Live xPlane imaging had excellent feasibility regardless of foetal position; using rotation, lateral and vertical tilts, all cardiac structures were identified from a unique reference plane. Live 3D surface imaging had variable feasibility depending on the target structure. Only 10% of the volume dataset offered comprehensive imaging of intracardiac views., Conclusion: The new xMATRIX transabdominal transducer allows a multimodality approach to the foetal heart. Further studies that include foetuses with cardiac malformations are required., (Copyright © 2013 Elsevier Masson SAS. All rights reserved.)

With the emergence of the mouse as the predominant model system for studying mammalian brain development, in utero imaging methods are urgently required to analyze the dynamics of brain growth and patterning in mouse embryos. To address this need, we combined synthetic focusing with a high-frequency (38-MHz) annular-array ultrasound imaging system for extended depth-of-field, coded excitation for improved penetration and respiratory-gated transmit/receive. This combination allowed non-invasive in utero acquisition of motion-free 3-D data from individual embryos in approximately 2 min, and data from four or more embryos in a pregnant mouse in less than 30 min. Data were acquired from 148 embryos spanning 5 d of early to mid-gestational stages of brain development. The results indicated that brain anatomy and cerebral vasculature can be imaged with this system and that quantitative analyses of segmented cerebral ventricles can be used to characterize volumetric changes associated with mouse brain development., (Copyright © 2013 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.)

Objectives: A survey was conducted of acoustic output data received by the US Food and Drug Administration for diagnostic ultrasound devices whose indications for use include fetal applications to assess trends in maximum available acoustic output over time., Methods: Data were collected from 124 regulatory submissions received between 1984 and 2010. Data collection excluded transducers not indicated for diagnostic fetal imaging. The output parameters of ultrasonic power, mean center frequency, and bone thermal index (TIB) were extracted or computed from the submissions for 3 periods: 1984-1989, 1992-1997, and 2005-2010. The data were stratified according to the following imaging modes: M-mode, B/M-mode, pulsed wave Doppler, color flow Doppler, and continuous wave Doppler., Results: Ultrasonic power and maximum TIB values have increased roughly an order of magnitude from pre-1991 to post-1991 periods; the center frequency has decreased somewhat (4.2 to 3.4 MHz). The percentage of Doppler-mode transducers has increased substantially over time, with the majority of the diagnostic fetal imaging transducers currently designed to operate in Doppler modes; this increase is particularly important, since Doppler modes generate much higher TIB levels than B/M-modes. Color flow Doppler ultrasound currently operates at the highest mean ultrasonic power level (with a 14-fold increase over time)., Conclusions: The observed trends in increased acoustic output for both Doppler and non-Doppler modes underscore the widely recognized importance of adherence to the ALARA (as low as reasonably achievable) principle and prudent use in fetal ultrasound imaging.

Correct estimation of gestational age is essential for any study of ultrasound biometry and for everyday clinical practice. However, inconsistency in pregnancy dating may occur through differences in measurement methods or errors during measurement. In the INTERGROWTH-21(st) Project, pregnancies are dated by the last menstrual period, provided that it is certain and associated with a regular menstrual cycle, and the gestational age by dates concurs with a first-trimester ultrasound crown-rump length (CRL) estimation. Hence, there was a need to standardise CRL measurement methodology across the study sites in this international, multicentre project to avoid systematic differences in dating. To achieve uniformity we undertook the following steps: the ultrasound technique was standardised by disseminating an illustrated, operating manual describing CRL plane landmarks and calliper application, and posters describing the correct acquisition technique were disseminated for quick reference. To ensure that all ultrasonographers understood the methodology, they forwarded a log-book to the INTERGROWTH-21(st) Ultrasound Coordinating Unit, containing the answers to a written test on the manual material and five images of a correctly acquired CRL. Interpretation of CRL was also standardised by ensuring that the same CRL regression formula was used across all study sites. These methods should minimise potential systematic errors in dating associated with pooling data from different health institutions, and represent a model for standardising CRL measurement in future studies., (© 2013 The Authors BJOG An International Journal of Obstetrics and Gynaecology © 2013 RCOG.)