Lateral Neck Bulging and Pain on Swallowing in a Young Man

A 28-year-old man presents with a bulge on the left side of his neck and severe stabbing pain during swallowing. He had a history of a neck contusion 1 year prior with subcutaneous bleeding that had improved. What is your diagnosis?

Prenatal diagnosis of interrupted aortic arch using high-definition flow render mode and spatiotemporal image correlation

OBJECTIVES

To evaluate the clinical utility of two dimensional (2D) ultrasound combined with spatiotemporal image correlation (STIC) in diagnosing interrupted aortic arch (IAA) in fetal life.

METHODS

A total of 53 cases of fetal IAA were diagnosed using 2D ultrasound combined with STIC, and 53 normal fetuses of the same gestational week were selected. These cases were retrospectively analyzed to assess the utility of employing 2D ultrasound combined with STIC in the diagnosis of IAA.

RESULTS

2D ultrasound combined with STIC detected 22 cases of type A IAA, 24 cases of type B IAA, and seven cases of type C IAA. Furthermore, combining 2D ultrasound with STIC enabled dynamic visualization of the IAA, aiding in prenatal diagnosis. The diagnostic coincidence rate of IAA was found to be higher in the HD-flow combined with STIC than that in the 2D combined with HD-flow.

CONCLUSION

HD-flow combined with STIC can assist in diagnosing fetal IAA, and this technique has important clinical value.

Enhancing Fetal Anomaly Detection in Ultrasonography Images: A Review of Machine Learning-Based Approaches

Fetal development is a critical phase in prenatal care, demanding the timely identification of anomalies in ultrasound images to safeguard the well-being of both the unborn child and the mother. Medical imaging has played a pivotal role in detecting fetal abnormalities and malformations. However, despite significant advances in ultrasound technology, the accurate identification of irregularities in prenatal images continues to pose considerable challenges, often necessitating substantial time and expertise from medical professionals. In this review, we go through recent developments in machine learning (ML) methods applied to fetal ultrasound images. Specifically, we focus on a range of ML algorithms employed in the context of fetal ultrasound, encompassing tasks such as image classification, object recognition, and segmentation. We highlight how these innovative approaches can enhance ultrasound-based fetal anomaly detection and provide insights for future research and clinical implementations. Furthermore, we emphasize the need for further research in this domain where future investigations can contribute to more effective ultrasound-based fetal anomaly detection.

High-Volume-Rate 3-D Ultrasound Imaging Using Fast-Tilting and Redirecting Reflectors

Three-dimensional ultrasound imaging has many advantages over 2-D imaging such as more comprehensive tissue evaluation and less operator dependence. However, developing a low-cost and accessible 3-D ultrasound solution with high volume rate and imaging quality remains a challenging task. Recently, we proposed a 3-D ultrasound imaging technique: fast acoustic steering via tilting electromechanical reflectors (FASTER), which uses a fast-tilting acoustic reflector to steer ultrafast plane waves elevationally to achieve high-volume-rate 3-D imaging with conventional 1-D transducers. However, the initial FASTER implementation requires a water tank for acoustic wave conduction and cannot be conveniently used for regular handheld scanning. To address these limitations, here, we developed a novel ultrasound probe clip-on device that encloses a fast-tilting reflector, a redirecting reflector, and an acoustic wave conduction medium. The new FASTER 3-D imaging device can be easily attached to or removed from clinical ultrasound transducers, allowing rapid transformation from 2-D to 3-D imaging. In vitro B-mode studies demonstrated that the proposed method provided comparable imaging quality to conventional, mechanical-translation-based 3-D imaging while offering a much faster volume rate (e.g., 300 versus  ∼  10 Hz). We also demonstrated 3-D power Doppler (PD) and 3-D super-resolution ultrasound localization microscopy (ULM) with the FASTER device. An in vivo imaging study showed that the FASTER device could clearly visualize the 3-D anatomy of the basilic vein. These results suggest that the newly developed redirecting reflector and the clip-on device could overcome key hurdles for future clinical translation of the FASTER 3-D imaging technology.

High Volume Rate 3-D Ultrasound Imaging Using Fast-Tilting and Redirecting Reflectors

3-D ultrasound imaging has many advantages over 2-D imaging such as more comprehensive tissue evaluation and less operator dependence. Although many 3-D ultrasound imaging techniques have been developed in the last several decades, a low-cost and accessible solution with high imaging volume rate and imaging quality remains elusive. Recently we proposed a new, high volume rate 3-D ultrasound imaging technique: Fast Acoustic Steering via Tilting Electromechanical Reflectors (FASTER), which uses a water-immersible and fast-tilting acoustic reflector to steer ultrafast plane waves in the elevational direction to achieve high volume rate 3-D ultrasound imaging with conventional 1-D array transducers. However, the initial implementation of FASTER imaging only involves a single fast-tilting acoustic reflector, which is inconvenient to use because the probe cannot be held in the regular upright position. Also, conventional FASTER imaging can only be performed inside a water tank because of the necessity of using water for acoustic conduction. To address these limitations of conventional FASTER, here we developed a novel ultrasound probe clip-on device that encloses a fast-tilting reflector, a redirecting reflector, and an acoustic wave conduction medium. The new FASTER 3-D imaging device can be easily attached to or removed from clinical ultrasound transducers, allowing rapid transformation from 2-D to 3-D ultrasound imaging. In vitro B-mode imaging studies demonstrated that the proposed method provided comparable imaging quality (e.g., spatial resolution and contrast-to-noise ratio) to conventional, mechanical-translation-based 3-D imaging while providing a much faster 3-D volume rate (e.g., 300 Hz vs ∼10 Hz). In addition to B-mode imaging, we also demonstrated 3-D power Doppler imaging and 3-D super-resolution ultrasound localization microscopy with the newly developed FASTER device. An in vivo imaging study showed that the FASTER device could clearly visualize the 3-D anatomy of the basilic vein of a healthy volunteer, and customized beamforming was implemented to accommodate the speed of sound difference between the acoustic medium and the imaging object (e.g., soft tissue). These results suggest that the newly developed redirecting reflector and the clip-on device could overcome key hurdles for future clinical translation of the FASTER 3-D imaging technology.

Application of Color Doppler with 3- and 4-Dimensional Ultrasonography in the Prenatal Evaluation of Fetal Extracardiac and Placental Abnormalities

Using color Doppler flow imaging or high-definition flow imaging with three-dimensional volume or spatio-temporal image correlation (STIC) in the glass-body mode allows displaying both gray-scale and color information of the heart cycle-related flow events and vessel spatial relationship. Conventionally, STIC in the glass-body mode has been used to examine the fetal heart and assess heart defects. Recently, a novel application of STIC in the visualization of abdominal precordial veins and intraplacental vascularization in singleton pregnancies has been reported. The aim of this present review is to discuss the use of color Doppler with three- and four-dimensional ultrasonography in the evaluation of extracardiac, placental, umbilical cord and twin abnormalities with examples. The glass-body mode is complementary to conventional 2D ultrasonography. Further studies are required to investigate use of the glass-body mode in the assessment of intraplacental vascularization in singleton and twin pregnancies.

3-D Coherent Multi-Transducer Ultrasound Imaging with Sparse Spiral Arrays

Coherent multi-transducer ultrasound (CoMTUS) creates an extended effective aperture through the coherent combination of multiple arrays, which results in images with enhanced resolution, extended field-of-view, and higher sensitivity. The subwavelength localization accuracy of the multiple transducers required to coherently beamform the data is achieved by using the echoes backscattered from targeted points. In this study, CoMTUS is implemented and demonstrated for the first time in 3-D imaging using a pair of 256-element 2-D sparse spiral arrays, which keep the channel count low and limit the amount of data to be processed. The imaging performance of the method was investigated using both simulations and phantom tests. The feasibility of free-hand operation is also experimentally demonstrated. Results show that, in comparison to a single dense array system using the same total number of active elements, the proposed CoMTUS system improves spatial resolution (up to 10 times) in the direction where both arrays are aligned, contrast-to-noise-ratio (CNR, up to 46%), and generalized CNR (up to 15%). Overall, CoMTUS shows a narrower main lobe and higher contrast-to-noise ratio, which results in an increased dynamic range and better target detectability.

Belimumab use during pregnancy: a summary of birth defects and pregnancy loss from belimumab clinical trials, a pregnancy registry and postmarketing reports

OBJECTIVE

Describe available data on birth defects and pregnancy loss in women with systemic lupus erythematosus (SLE) exposed to belimumab.

METHODS

Data collected from belimumab clinical trials, the Belimumab Pregnancy Registry (BPR), and postmarketing/spontaneous reports up to 8 March 2020 were described. Belimumab exposure timing, concomitant medications and potential confounding factors were summarised descriptively.

RESULTS

Among 319 pregnancies with known outcomes (excluding elective terminations), 223 ended in live births from which birth defects were identified in 4/72 (5.6%) in belimumab-exposed pregnancies and 0/9 placebo-exposed pregnancies across 18 clinical trials, 10/46 (21.7%) belimumab-exposed pregnancies in the BPR prospective cohort (enrolled prior to pregnancy outcome) and 0/4 belimumab-exposed pregnancies in the BPR retrospective cohort (enrolled after pregnancy outcome), and 1/92 (1.1%) in belimumab-exposed pregnancies from postmarketing/spontaneous reports. There was no consistent pattern of birth defects across datasets. Out of pregnancies with known outcomes (excluding elective terminations), pregnancy loss occurred in 31.8% (35/110) of belimumab-exposed women and 43.8% (7/16) of placebo-exposed women in clinical trials; 4.2% (2/48) of women in the BPR prospective cohort and 50% (4/8) in the BPR retrospective cohort; and 31.4% (43/137) of belimumab-exposed women from postmarketing/spontaneous reports. All belimumab-exposed women in clinical trials and the BPR received concomitant medications and had confounding factors and/or missing data.

CONCLUSIONS

Observations reported here add to limited data published on pregnancy outcomes following belimumab exposure. Low numbers of exposed pregnancies, presence of confounding factors/other biases, and incomplete information preclude informed recommendations regarding risk of birth defects and pregnancy loss with belimumab use.

Imaging of placental circulations by 4D sonography with high-definition flow and spatiotemporal image correlation technology

Conventionally, two- and three- dimensional color Doppler ultrasonography are used to examine the placental vascularization, but there are limitations in the examinations. In this report, spatiotemporal image correlation (STIC) volume acquisition in high-definition flow, displayed in glass-body mode was used to study the placental vascularization in eight pregnancies. At 20 weeks' gestation, STIC technique allowed visualization of blood flow in the intraplacental branches of the umbilical artery (IPB) and the spiral artery jets in a cardiac cycle. In particular, blood flow from a mega jet penetrating more than half of the placental thickness was demonstrated. Small blood flow from a tertiary order branch of the IPB traversing the placenta and sharply diminishing into the uterine wall was also demonstrated. There were differences in the IPB pattern between normal pregnancies and pregnancies at risk of fetal growth restriction/pre-eclampsia. There were also differences in the appearance of IPB between 20- and 33-weeks' gestation. The results of this report support that it is feasible to use STIC technology to study the placental vascularization. This novel application of STIC technology can increase the understanding of the complex vascularization.

Fetal cardiac sectional schemas - Normal and abnormal. Part 1: Upper abdominal and thoracic sections

Background

A representational illustrated cardiac schema is useful for understanding and interpreting normal and abnormal fetal echocardiographic findings.

Aim

Normal and abnormal fetal echocardiographic images can be better appreciated with the support of sectional schemas.

Settings and Design

An attempt is made to include normal and abnormal variations in both grayscale and color images for easy understanding with the help of the schemas.

Materials and Methods

The fetal cardiac sectional schemas are drawn by the author, using Microsoft Office Word drawing canvas. It is based on the best grayscale, color Doppler, power-angio, 3-dimensional, and high definition flow ultrasound images, supported by embryological and anatomic specimens in literature. Different sections are drawn in accordance with the planes suggested by Society for Maternal-Fetal Medicine, Society of Radiologists in Ultrasound, American College of Obstetricians and Gynecologists, American Institute of Ultrasound in Medicine, American College of Radiology, and American Society of Echocardiography. Every effort has been meticulously pursued to match with the best ultrasound images with minor modifications for better clarity, understanding, and reproducibility.

Results

The drawings include normal and most of the common cardiac anomalies depicting different sectional views starting from the abdomen and upward. Each drawing complies with the ultrasound images. Users with basic computer knowledge can easily modify these images using them as templates for reference, reporting, and publications.

Conclusions

An attempt is made to represent the fetal echocardiographic images by simplified memorable sectional schemas. These schemas will facilitate a better understanding and interpretation of various normal and abnormal fetal echocardiographic images. Being electronically transmittable, these schemas can be used as templates for further modifications.

A Deep Learning Approach for the Assessment of Signal Quality of Non-Invasive Foetal Electrocardiography

Non-invasive foetal electrocardiography (NI-FECG) has become an important prenatal monitoring method in the hospital. However, due to its susceptibility to non-stationary noise sources and lack of robust extraction methods, the capture of high-quality NI-FECG remains a challenge. Recording waveforms of sufficient quality for clinical use typically requires human visual inspection of each recording. A Signal Quality Index (SQI) can help to automate this task but, contrary to adult ECG, work on SQIs for NI-FECG is sparse. In this paper, a multi-channel signal quality classifier for NI-FECG waveforms is presented. The model can be used during the capture of NI-FECG to assist technicians to record high-quality waveforms, which is currently a labour-intensive task. A Convolutional Neural Network (CNN) is trained to distinguish between NI-FECG segments of high and low quality. NI-FECG recordings with one maternal channel and three abdominal channels were collected from 100 subjects during a routine hospital screening (102.6 min of data). The model achieves an average 10-fold cross-validated AUC of 0.95 ± 0.02. The results show that the model can reliably assess the FECG signal quality on our dataset. The proposed model can improve the automated capture and analysis of NI-FECG as well as reduce technician labour time.

Prenatal diagnosis of fetal inferior vena cava malformation using HDlive flow combined with spatiotemporal image correlation

OBJECTIVES

This study aimed to examine the application value of high-definition live (HDlive) flow combined with spatiotemporal image correlation (STIC) in the diagnosis of fetal inferior vena cava malformation (IVCM).

METHODS

Twenty cases of IVCMs were diagnosed using two-dimensional HDlive flow and HDlive flow combined with STIC and retrospectively analyzed to examine the impact of using HDlive flow combined with STIC in the diagnosis of IVCM.

RESULTS

HDlive flow combined with STIC detected one case of duplicated IVC, four cases of left IVC (two cases with complex malformations), and 15 cases of interrupted IVC (two cases of isolated IVC disconnection, five cases with left atrial heterogeneous syndrome, and eight cases with other complex malformations).

CONCLUSION

HDlive flow combined with STIC can help in the diagnosis of IVCM, and this technique has important clinical value.

Biplane mode for more precise intrauterine procedures

The evolution of ultrasound and the introduction of 3- and 4-dimensional ultrasound techniques led to a shift in the perception and usage of ultrasound in fetal medicine. The biplane mode might help in multiple fetal procedures, including but not limited to basic intrauterine thoracocentesis, thoracoamniotic shunting, amnioreduction, amnioinfusion, cordocentesis, intraumbilical infusion, and umbilical cord coagulation, with a possible reduction in the complication rate. Despite its theoretical usefulness, more studies are required to assess the clinical importance of this technique.

Imaging of fetal precordial venous system by four-dimensional ultrasound with spatiotemporal image correlation technology

Despite the use of two- and three- dimensional color Doppler ultrasonography, the prenatal sonographic evaluation of precordial venous system remains difficult. Spatiotemporal image correlation (STIC) technology has been well described for the assessment of the fetal heart, but not of precordial venous system. As demonstrated in this report, it is feasible to use four-dimensional ultrasound with STIC rendered volume in glass-body mode and tomographic ultrasound imaging to image this system including the connection and drainage of the ductus venosus, hepatic veins and inferior vena cava to the fetal heart. This novel approach can increase the understanding of this venous system.

Antenatal diagnosis of congenital heart disease by 3D ultrasonography using spatiotemporal image correlation with HDlive Flow and HDlive Flow silhouette rendering modes

This pictorial review describes the assessment of a great variety of types of congenital heart disease by three-dimensional ultrasonography with spatiotemporal image correlation using HDlive and the HDlive Flow silhouette rendering mode. These technologies provide fetal heart surface patterns by using a fixed virtual light source that propagates into the tissues, permitting a detailed reconstruction of the heart structures. In this scenario, ultrasound operators can freely select a better light source position to enhance the anatomical details of the fetal heart. HDlive and the HDlive Flow silhouette rendering mode improve depth perception and the resolution of anatomic cardiac details and blood vessel walls compared to standard two-dimensional ultrasonography.

Artificial Intelligence in Obstetric Ultrasound: An Update and Future Applications

Artificial intelligence (AI) can support clinical decisions and provide quality assurance for images. Although ultrasonography is commonly used in the field of obstetrics and gynecology, the use of AI is still in a stage of infancy. Nevertheless, in repetitive ultrasound examinations, such as those involving automatic positioning and identification of fetal structures, prediction of gestational age (GA), and real-time image quality assurance, AI has great potential. To realize its application, it is necessary to promote interdisciplinary communication between AI developers and sonographers. In this review, we outlined the benefits of AI technology in obstetric ultrasound diagnosis by optimizing image acquisition, quantification, segmentation, and location identification, which can be helpful for obstetric ultrasound diagnosis in different periods of pregnancy.

A 10-Year Retrospective Review of Prenatal Applications, Current Challenges and Future Prospects of Three-Dimensional Sonoangiography

Realistic reconstruction of angioarchitecture within the morphological landmark with three-dimensional sonoangiography (three-dimensional power Doppler; 3D PD) may augment standard prenatal ultrasound and Doppler assessments. This study aimed to (a) present a technical overview, (b) determine additional advantages, (c) identify current challenges, and (d) predict trajectories of 3D PD for prenatal assessments. PubMed and Scopus databases for the last decade were searched. Although 307 publications addressed our objectives, their heterogeneity was too broad for statistical analyses. Important findings are therefore presented in descriptive format and supplemented with the authors’ 3D PD images. Acquisition, analysis, and display techniques need to be personalized to improve the quality of flow-volume data. While 3D PD indices of the first-trimester placenta may improve the prediction of preeclampsia, research is needed to standardize the measurement protocol. In highly experienced hands, the unique 3D PD findings improve the diagnostic accuracy of placenta accreta spectrum. A lack of quality assurance is the central challenge to incorporating 3D PD in prenatal care. Machine learning may broaden clinical translations of prenatal 3D PD. Due to its operator dependency, 3D PD has low reproducibility. Until standardization and quality assurance protocols are established, its use as a stand-alone clinical or research tool cannot be recommended.

Applications of Advanced Ultrasound Technology in Obstetrics

Over the years, there have been several improvements in ultrasound technologies including high-resolution ultrasonography, linear transducer, radiant flow, three-/four-dimensional (3D/4D) ultrasound, speckle tracking of the fetal heart, and artificial intelligence. The aims of this review are to evaluate the use of these advanced technologies in obstetrics in the midst of new guidelines on and new techniques of obstetric ultrasonography. In particular, whether these technologies can improve the diagnostic capability, functional analysis, workflow, and ergonomics of obstetric ultrasound examinations will be discussed.

A two-steps implementation of 3D ultrasound imaging in frequency domain with 1D array transducer

Compared with B-mode imaging, three-dimensional (3D) ultrasound imaging is more helpful in research and clinical application. At present, the 3D ultrasound images can be acquired directly with two-dimensional (2D) array transducer or reconstructed from a series of B-mode images obtained with one-dimensional (1D) array transducer. Imaging with 2D array transducer can achieve a high frame rate, but suffering from the complexity of the imaging system, such as the large amount of channels, and high computational complexity. Reconstructing 3D images from a series of B-mode images can be implemented by recording the position and orientation of the slice images. This is a low-cost and flexible imaging method, but usually suffering from the low imaging quality and low frame rate. In our previous work, a novel 3D ultrasound imaging method in frequency domain with a moved 1D array transducer is presented. This method can reduce the computational complexity with FFT, and get improved imaging quality and frame rate to some extent. Besides, this method can be adopted to construct images with a row-column-addressed 2D array, which can reduce the amount of channels effectively. In this paper, a two-steps implementation of this imaging method is proposed, in which the combined implementation of the 3D imaging is decomposed to two steps of 2D imaging processes in Frequency domain. In the first step, the received echoes of the 1D array transducer at each position are processed with a 2D imaging processes in the lateral- axial planes. In the second step, a 2D imaging processes is preformed in the planes of orthogonal to the transducer. Simulation results show that the two-steps implementation can achieve almost the same imaging quality to the previous work. Compared with the implementation of 3D imaging in our previous work, the proposed two-steps implementation can be carried out with parallel process to improve the computational efficiency, or carried out with loop to reduce the hardware cost. Besides, the first step can be performed with a conventional DAS imaging method when a cylindrical wave is adopted for imaging. The influence of the spread angle of the field is also discussed.

Reliability of Sonography-based Volume Computer Aided Diagnosis in the Normal Fetal Heart

OBJECTIVES

To explore the inter- and intra-observer reliability of Sonography-based Volume Computer Aided Diagnosis (SonoVCAD) in the display of 8 diagnostic planes of fetal echocardiography and to evaluate its efficiency.

METHODS

Three-dimensional volume data sets of the 56 normal singleton fetuses were acquired from a 4-chamber view by using a volume probe. After processing the data sets by using SonoVCAD, 8 cardiac diagnostic planes were displayed automatically. Three doctors with different experiences of performing fetal echocardiography evaluated each diagnostic plane and the success rates of 8 diagnostic planes were calculated. Inter-observer and intra-observer reliabilities were estimated by Cohen's kappa statistics.

RESULTS

A total of 276 volume data sets acquired from the 56 normal fetuses were used for SonoVCAD analysis and display. The success rate of each diagnostic section was more than 90%, ranging from 90.6% to 99.6%. Among 276 volumes, 81.5% (225/276) of volumes were able to generate all 8 diagnostic views successfully. Moderate to substantial agreement (kappa, 0.509-0.794) was found between 2 less experienced operators. Moderate to near-perfect agreement (kappa, 0.439-0.933) was found between an expert and 2 less experienced sonographers. Intra-observer reliability was substantial to near-perfect (kappa, 0.602-0.903). The efficiency of SonoVCAD was assessed. The expert spent less time than 2 less experienced examiners (P < 0.001) but no significant difference was found between 2 less experienced examiners (P = 0.176). Besides, SonoVCAD consumed significantly less time than 2-dimensional ultrasound (P < 0.001).

CONCLUSIONS

SonoVCAD can significantly improve the success rates of 8 diagnostic planes in fetal echocardiography with low operator dependency, good reproducibility and high efficiency.

Accuracy of automated three-dimensional ultrasound imaging technique for fetal head biometry

OBJECTIVES

To evaluate the accuracy of an automated three-dimensional (3D) ultrasound technique for fetal intracranial measurements compared with manual acquisition.

METHODS

This was a prospective observational study of patients presenting for routine anatomical survey between 18 + 0 and 22 + 6 weeks' gestation. After providing informed consent, each patient underwent two consecutive ultrasound examinations of the fetal head, one by a sonographer and one by a physician. Each operator obtained manual measurements of the biparietal diameter (BPD), head circumference (HC), transcerebellar diameter (TCD), cisterna magna (CM) and posterior horn of the lateral ventricle (Vp), followed by automated measurements of these structures using an artificial intelligence-based tool, SonoCNS® Fetal Brain. Both operators repeated the automated approach until all five measurements were obtained in a single sweep, up to a maximum of three attempts. The accuracy of automated measurements was compared with that of manual measurements using intraclass correlation coefficients (ICC) by operator type, accounting for patient and ultrasound characteristics.

RESULTS

One hundred and forty-three women were enrolled in the study. Median body mass index was 24.0 kg/m² (interquartile range (IQR), 22.5-26.8 kg/m² ) and median subcutaneous thickness was 1.6 cm (IQR, 1.3-2.0 cm). Fifteen (10%) patients had at least one prior Cesarean delivery, 17 (12%) had other abdominal surgery and 78 (55%) had an anterior placenta. Successful acquisition of the automated measurements was achieved on the first, second and third attempts in 70%, 22% and 3% of patients, respectively, by sonographers and in 76%, 16% and 3% of cases, respectively, by physicians. The automated algorithm was not able to identify and measure all five structures correctly in six (4%) and seven (5%) patients scanned by the sonographers and physicians, respectively. The ICCs reflected good reliability (0.80-0.88) of the automated compared with the manual approach for BPD and HC and poor to moderate reliability (0.23-0.50) for TCD, CM and Vp. Fetal lie, head position, placental location, maternal subcutaneous thickness and prior Cesarean section were not associated with the success or accuracy of the automated technique.

CONCLUSIONS

Automated 3D ultrasound imaging of the fetal head using SonoCNS reliably identified and measured BPD and HC but was less consistent in accurately identifying and measuring TCD, CM and Vp. While these results are encouraging, further optimization of the automated technology is necessary prior to incorporation of the technique into routine sonographic protocols. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Prenatal evaluation of fetal atrioventricular valves by real-time 4D volume imaging with electronic matrix probe

Background

The purpose of this study is to evaluate the feasibility using real-time four-dimensional (RT 4D) volume imaging with electronic matrix probe to observe the morphology of atrioventricular valves in normal and abnormal fetuses, measure the area and circumference of atrioventricular valves in normal fetuses and analyze the correlation with gestational age.

Methods

RT 4D volume imaging with electronic matrix probe was used to collect cardiac volume data of 162 normal fetuses with the gestational age from 22 to 32 weeks and 19 fetuses with atrioventricular valves abnormalities were also enrolled. All the volume data were analyzed and processed in real-time. The morphology of mitral and tricuspid valves was observed in surface mode. The area and circumference of valves were measured in a 4D render view at the end of diastole and analyzed the correlation with gestational age.

Results

In 148 of 162 fetuses (91%), the 4D rendered image could be successfully obtained, which clearly showed the morphology of the atrioventricular valves. The area and circumference of mitral and tricuspid valves were positively correlated with gestational age (P < 0.01). Furthermore, 4D rendered images were successfully obtained in 17 of 19 fetuses (89%) with atrioventricular valves abnormalities.

Conclusions

The reference range of the area and circumference of atrioventricular valves in normal fetuses at different gestational weeks could be determined by using the RT 4D volume imaging with electronic matrix probe, which can provide certain diagnostic information for the clinic. The RT 4D images could display the valves morphology vividly in both normal and abnormal fetuses, including some subtle lesions which are not identified by traditional two-dimensional (2D) echocardiography. It is feasible to use the RT 4D volume imaging with electronic matrix probe to perform the prenatal evaluation in the fetal atrioventricular valves.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12947-021-00240-7.

Normal Fetal Umbilical, Portal, and Hepatic Venous System: Four-dimensional STIC Rendering

Online supplemental material is available for this article.

Implementation of a statewide, multisite fetal tele-echocardiography program: evaluation of more than 1100 fetuses over 9 years

OBJECTIVES

We sought to describe the implementation and effectiveness of a statewide fetal tele-echocardiography program serving a resource-limited population.

STUDY DESIGN

In 2009, our heart center established six satellite clinics for fetal tele-echocardiography around the state. We retrospectively reviewed all fetal tele-echocardiograms performed through 2018. Yearly statewide prenatal detection rates of operable congenital heart disease were queried from the Society of Thoracic Surgeons database.

RESULT

In 1164 fetuses, fetal tele-echocardiography identified all types of congenital heart disease, with a sensitivity of 74% and specificity of 97%. For the detection of ductal-dependent congenital heart disease, fetal tele-echocardiography was 100% sensitive and specific. Between 2009 and 2018, annual statewide prenatal detection rates of congenital heart disease requiring heart surgery in the first 6 months of life rose by 159% (17-44%; R² = 0.88, p < 0.01).

CONCLUSIONS

The present study provides a framework for an effective, large-scale fetal tele-echocardiography program.

Obstetric ultrasound: where are we and where are we going?

Diagnostic ultrasound (DUS) is, arguably, the most common technique used in obstetrical practice. From A mode, first described by Ian Donald for gynecology in the late 1950s, to B mode in the 1970s, real-time and gray-scale in the early 1980s, Doppler a little later, sophisticated color Doppler in the 1990s and three dimensional/four-dimensional ultrasound in the 2000s, DUS has not ceased to be closely associated with the practice of obstetrics. The latest innovation is the use of artificial intelligence which will, undoubtedly, take an increasing role in all aspects of our lives, including medicine and, specifically, obstetric ultrasound. In addition, in the future, new visualization methods may be developed, training methods expanded, and workflow and ergonomics improved.

Additional benefits of three-dimensional ultrasound for prenatal assessment of twins

Three-dimensional ultrasound (3DUS) may provide additional information for prenatal assessment of twins. It may improve the diagnostic confidence of dating, nuchal translucency (NT) and chorionicity assignment in twin pregnancies. The "virtual 3DUS placentoscopy" can guide selective fetoscopic laser photocoagulation (SFLP) to treat twin-twin transfusion syndrome (TTTS). Volumetric assessment of the dysmorphic acardiac twin with the Virtual Organ Computer-aided Analysis (VOCAL) software is more accurate than the conventional ultrasound measurement. Twin anemia polycythemia (TAP) sequence and selective intrauterine growth restriction (sIUGR) may be clinically monitored with 3DUS placental volume (PV) and power Doppler vascular indices. Congenital anomalies are more common in twins. Evaluation of fetal anomalies with 3DUS could assist perinatal management. The 3DUS power Doppler can provide a better understanding of true and false umbilical cord knots, which are commonly found in monoamniotic (MA) twins. Single demise in monochorionic (MC) twin pregnancies can cause severe neurologic morbidity in the surviving co-twin. Prenatal prediction of brain injury in the surviving co-twin with unremarkable neurosonographic examination is difficult. The 3DUS power Doppler may aid in prenatal detection of subtle abnormal cerebral perfusion. Prenatal assessment of conjoined twins with 3DUS is important if emergency postnatal surgical separation is anticipated. There is no significant additional advantage in using real-time 3DUS to guide prenatal interventions. Assessment of the cervix and pelvic floor during twin pregnancies is enhanced with 3DUS. Due to lack of high-quality studies, routine prenatal 3DUS in twin pregnancies needs to be balanced with risks of excessive ultrasound exposure.

Four-dimensional US of a Fetal Heart at 16 Weeks Gestation

Online supplemental material is available for this article.