Advantages of 3D ultrasound in the assessment of fetal abnormalities

Clinical Ultrasound Applications in Obstetrics and Gynecology in the Year 2024

Ultrasound imaging stands as a fundamental technology in the realms of obstetrics and gynecology, utilizing high-frequency sound waves to create detailed images of the internal structures of the body [...].

Fetal face shape analysis from prenatal 3D ultrasound images

3D ultrasound imaging of fetal faces has been predominantly confined to qualitative assessment. Many genetic conditions evade diagnosis and identification could assist with parental counselling, pregnancy management and neonatal care planning. We describe a methodology to build a shape model of the third trimester fetal face from 3D ultrasound and show how it can objectively describe morphological features and gestational-age related changes of normal fetal faces. 135 fetal face 3D ultrasound volumes (117 appropriately grown, 18 growth-restricted) of 24-34 weeks gestation were included. A 3D surface model of each face was obtained using a semi-automatic segmentation workflow. Size normalisation and rescaling was performed using a growth model giving the average size at every gestation. The model demonstrated a similar growth rate to standard head circumference reference charts. A landmark-free morphometry model was estimated to characterize shape differences using non-linear deformations of an idealized template face. Advancing gestation is associated with widening/fullness of the cheeks, contraction of the chin and deepening of the eyes. Fetal growth restriction is associated with a smaller average facial size but no morphological differences. This model may eventually be used as a reference to assist in the prenatal diagnosis of congenital anomalies with characteristic facial dysmorphisms.

3D printing of foetal vascular rings: feasibility and applicability

BACKGROUND

Vascular rings (VRs) exhibit complex and diverse forms that are difficult to conceptualize using traditional two-dimensional (2D) schematic. Inexperienced medical students and parents who lack a medical technology background face significant challenges in understanding VRs. The purpose of this research is to develop three-dimensional (3D) printing models of VRs to provide new technical imaging support for medical education and parental consultation.

METHODS

This study included 42 fetuses diagnosed as VRs. Foetal echocardiography, modeling and 3D printing were performed, and the dimensional accuracy of models was analyzed. The value of 3D printing in the teaching of VRs was analyzed based on comparing the test results before and after the teaching intervention of 48 medical students and the satisfaction survey. A brief survey was conducted to 40 parents to assess the value of the 3D printed model in prenatal consultations.

RESULTS

Forty models of VRs were successfully obtained, which reproduced the anatomical shape of the VRs space with high dimensional accuracy. No differences in the prelecture test results were noted between the 3D printing group and the 2D image group. After the lecture, the knowledge of both groups improved, but the postlecture score and the change in the prelecture versus postlecture score were greater in the 3D printing group, and the subjective satisfaction survey feedback in the 3D printing group was also better (P < 0.05). Similar results were observed from the parental questionnaire, the vast majority of parents have an enthusiastic and positive attitude towards the use of 3D printed models and suggest using them in future prenatal consultations.

CONCLUSIONS

Three-dimensional printing technology providing a new tool for effectively displaying different types of foetal VRs. This tool helps physicians and families understand the complex structure of foetal great vessels, positively impacting medical instruction and prenatal counselling.

A review on deep-learning algorithms for fetal ultrasound-image analysis

Deep-learning (DL) algorithms are becoming the standard for processing ultrasound (US) fetal images. A number of survey papers in the field is today available, but most of them are focusing on a broader area of medical-image analysis or not covering all fetal US DL applications. This paper surveys the most recent work in the field, with a total of 153 research papers published after 2017. Papers are analyzed and commented from both the methodology and the application perspective. We categorized the papers into (i) fetal standard-plane detection, (ii) anatomical structure analysis and (iii) biometry parameter estimation. For each category, main limitations and open issues are presented. Summary tables are included to facilitate the comparison among the different approaches. In addition, emerging applications are also outlined. Publicly-available datasets and performance metrics commonly used to assess algorithm performance are summarized, too. This paper ends with a critical summary of the current state of the art on DL algorithms for fetal US image analysis and a discussion on current challenges that have to be tackled by researchers working in the field to translate the research methodology into actual clinical practice.

A Novel Framework for Abnormal Risk Classification over Fetal Nuchal Translucency Using Adaptive Stochastic Gradient Descent Algorithm

In most maternity hospitals, an ultrasound scan in the mid-trimester is now a standard element of antenatal care. More fetal abnormalities are being detected in scans as technology advances and ability improves. Fetal anomalies are developmental abnormalities in a fetus that arise during pregnancy, birth defects and congenital abnormalities are related terms. Fetal abnormalities have been commonly observed in industrialized countries over the previous few decades. Three out of every 1000 pregnant mothers suffer a fetal anomaly. This research work proposes an Adaptive Stochastic Gradient Descent Algorithm to evaluate the risk of fetal abnormality. Findings of this work suggest that proposed innovative method can successfully classify the anomalies linked with nuchal translucency thickening. Parameters such an accuracy, recall, precision, and F1-score are analyzed. The accuracy achieved through the suggested technique is 98.642.%.

Feasibility Analysis of 3D Printing With Prenatal Ultrasound for the Diagnosis of Fetal Abnormalities

OBJECTIVE

To assess the feasibility and accuracy of 3D printing with prenatal three-dimensional ultrasound (3DUS) in the diagnosis of fetal abnormalities.

METHODS

Fetuses initially diagnosed with various abnormalities were included in this retrospective study. The fetuses were examined by 3DUS, modeled, and 3D printed, and the dimensional accuracy of the 3D prints was analyzed. The effectiveness, demand, necessity of 3D printing, and the diagnostic accuracy of different methods were analyzed based on questionnaire responses from 40 senior ultrasound doctors and 40 postgraduate students.

RESULTS

A total of 12 fetuses with cleft lip and palate, spinal, heart, or brain abnormalities were included for detailed assessment. All deviations (mean deviation: 0.1 mm) between the original images and the final 3D prints lay within the consistency boundary (-1.12, 1.31 mm) (P > .05). In the subsequent analyses, 90.8% of the doctors and 94.2% of the students strongly agreed that 3D printing could precisely represent and depict fetal abnormalities. The average misdiagnosis rate of the doctors decreased from 5% to 0.4% after the application of 3D printing combined with 3DUS in comparison with 3DUS alone, and the corresponding value for the students dropped from 17.9% to 5.2%.

CONCLUSIONS

The errors in modeling and 3D printing based on 3DUS were within acceptable limits, and 3D printing improved the diagnosis of various fetal abnormalities.

A review of image processing methods for fetal head and brain analysis in ultrasound images

BACKGROUND AND OBJECTIVE

Examination of head shape and brain during the fetal period is paramount to evaluate head growth, predict neurodevelopment, and to diagnose fetal abnormalities. Prenatal ultrasound is the most used imaging modality to perform this evaluation. However, manual interpretation of these images is challenging and thus, image processing methods to aid this task have been proposed in the literature. This article aims to present a review of these state-of-the-art methods.

METHODS

In this work, it is intended to analyze and categorize the different image processing methods to evaluate fetal head and brain in ultrasound imaging. For that, a total of 109 articles published since 2010 were analyzed. Different applications are covered in this review, namely analysis of head shape and inner structures of the brain, standard clinical planes identification, fetal development analysis, and methods for image processing enhancement.

RESULTS

For each application, the reviewed techniques are categorized according to their theoretical approach, and the more suitable image processing methods to accurately analyze the head and brain are identified. Furthermore, future research needs are discussed. Finally, topics whose research is lacking in the literature are outlined, along with new fields of applications.

CONCLUSIONS

A multitude of image processing methods has been proposed for fetal head and brain analysis. Summarily, techniques from different categories showed their potential to improve clinical practice. Nevertheless, further research must be conducted to potentiate the current methods, especially for 3D imaging analysis and acquisition and for abnormality detection.

Clinically Relevant Prenatal Ultrasound Diagnosis of Umbilical Cord Pathology

Umbilical cord abnormalities are not rare, and are often associated with structural or chromosomal abnormalities, fetal intrauterine growth restriction, and poor pregnancy outcomes; the latter can be a result of prematurity, placentation deficiency or, implicitly, an increased index of cesarean delivery due to the presence of fetal distress, higher admission to neonatal intensive care, and increased prenatal mortality rates. Even if the incidence of velamentous insertion, vasa praevia and umbilical knots is low, these pathologies increase the fetal morbidity and mortality prenatally and intrapartum. There is a vast heterogeneity among societies’ guidelines regarding the umbilical cord examination. We consider the mandatory introduction of placental cord insertion examination in the first and second trimester to practice guidelines for fetal ultrasound scans. Moreover, during the mid-trimester scan, we recommend a transvaginal ultrasound and color Doppler assessment of the internal cervical os for low-lying placentas, marginal or velamentous cord insertion, and the evaluation of umbilical cord entanglement between the insertion sites whenever it is incidentally found. Based on the pathological description and the neonatal outcome reported for each entity, we conclude our descriptive review by establishing a new, clinically relevant classification of these umbilical cord anomalies.

Comparison of two-dimensional (2D) and three-dimensional (3D) ultrasonography for gestational ageing in the early to mid-pregnant bitch

Accuracy of prediction of the day of parturition in the bitch decreases with advancing pregnancy. We hypothesized that three‐dimensional (3D) volume ultrasonography may be superior for gestational ageing than 2D measurements. Thirty‐two pregnancy examinations were performed in 25 bitches of different breeds 21–34 days after the first mating. Ovulation date from serum progesterone concentrations was estimated for 15 bitches, and parturition date was recorded for all dogs. Inner chorionic cavity (ICC) diameters and ICC length of the conceptus were measured by 2D B‐mode, and ICC volume by 3D ultrasonography (Voluson^® i, GE Healthcare). Linear or exponential regressions between ICC measurements and time, i.e. days after estimated ovulation or days before parturition, were performed with significance set at p < .05. ICC volume increased exponentially over time, while ICC diameter showed a linear growth. ICC volume had similar accuracy (R² = .718, p < .001) to ICC diameter and ICC length (R² = .707 and R² = .728, p < .001) when analysed in relation to days after estimated ovulation or in relation to days before parturition (R² = .818, R² = .800 and R² = .810, p < .001 respectively). There were strong (R² ≥ .875) significant associations between all ICC measurements. In conclusion, ICC volume did not improve canine gestational ageing accuracy, which supports the continued use of the ICC diameter, particularly in light of the difficulty in obtaining 3D measurements. On the basis of ICC volume, the growth of the canine conceptus appeared to be exponential already during the first half of pregnancy.

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.

Amniotic band syndrome in a monochorionic diamniotic twin pregnancy after rupture of the dividing membrane in the early second trimester: A case report

BACKGROUND

Amniotic band syndrome is a rare phenomenon, but it can result in serious complications. We report herein our experience of amniotic band syndrome in a monochorionic diamniotic twin pregnancy where rupture of the dividing membrane occurred early in the second trimester.

CASE PRESENTATION

A 29-year-old nulliparous woman was referred to us for management of her monochorionic diamniotic twin pregnancy at 10 weeks of gestation. When we were unable to identify a dividing membrane at 15 weeks of gestation using two-dimensional ultrasonography, we used three-dimensional ultrasonography to confirm its absence. Both modalities showed that the left arm of baby B was swollen and attached to a membranous structure originating from the placenta at 18 weeks of gestation. Tangled umbilical cords were noted on magnetic resonance imaging at 18 weeks of gestation. Emergency cesarean delivery was performed at 30 weeks of gestation because of the nonreassuring fetal status of baby A. The left arm of baby B had a constrictive ring with a skin defect. Both neonates had an uncomplicated postnatal course and were discharged around 2 months after delivery.

CONCLUSIONS

Attention should be paid to the potential for amniotic band syndrome if rupture of the dividing membrane between twins is noted during early gestation.

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.

The Value of Obstetric Ultrasound in Screening Fetal Nervous System Malformation

BACKGROUND

The article uses ultrasound imaging standard section to examine the fetal central nervous system (CNS) in early pregnancy, combined with ultrasound imaging in the diagnosis of fetal CNS malformation in the middle and late pregnancy, to determine the feasibility of ultrasound imaging in the detection of CNS abnormalities in the first trimester of the fetus.

METHODS

The article selected 2701 pregnant women from the Department of Ultrasound in our hospital from November 2012 to November 2016 to screen for the transparent layer of the fetal neck in early pregnancy, with a total of 2751 cases. The article uses Madison V20 and Madison XG color Doppler ultrasound diagnostic instruments, the probe frequency is measured from 2.0-3.5 MHz, grouped according to gestational age, the statistical section of the case is displayed, and the transparent layer of the neck value is used to count the ultrasound image during early pregnancy. The detection of the CNS malformation by the standard section examination and the sensitivity, specificity, positive predictive value, and negative predictive value of the diagnosis may affect the cause of the CNS display rate.

RESULTS

The sensitivity, specificity, positive predictive value, and negative predictive value of the ultrasound standard section in the diagnosis of fetal CNS malformation in early pregnancy were 85.7%, 100%, 100%, and 99.9%, respectively. Through research, it is found that the use of ultrasound imaging standard section can effectively diagnose fetal CNS severe deformity in early pregnancy, and the detection rate of CNS malformation in early pregnancy is 85.7%. At the same time, the number of positive cases and CNS malformations in this group were few.

CONCLUSIONS

The positive cases detected in early pregnancy were severe malformations of the CNS. The diagnosis of other CNS malformations in the fetus needs further study.

Ex utero intrapartum treatment (EXIT) procedures

Ex Utero Intrapartum Treatment (EXIT) is a technique developed to safely and efficiently establish cardiopulmonary support at delivery while maintaining placental bypass. Indications for the EXIT approach are expanding and currently include EXIT-to-airway, EXIT-to-resection, EXIT-to-extracorporeal membrane oxygenation (ECMO), and EXIT-to-separation of conjoined twins. The EXIT technique involves planned partial delivery of the fetus via hysterotomy while maintaining uterine relaxation and placental support, allowing for the establishment of neonatal cardiopulmonary stability in a controlled manner. Fetal interventions performed during EXIT can include endotracheal intubation, tracheostomy, mass excision, removal of a temporary tracheal occlusive device, ECMO cannulation, and others. The most important aspect of an EXIT procedure is the formation of a multi-disciplinary team with broad expertise in fetal intervention to collaborate throughout the pre, intra, and post-partum periods. This chapter reviews the prenatal workup, decision making, surgical indications, and operative considerations associated with EXIT procedures.