Trends in prenatal diagnosis of critical cardiac defects in an integrated obstetric and pediatric cardiac imaging center

The Role of Collaboration in Prenatal Congenital Heart Disease Diagnosis: A Comparison of Maternal-Fetal Medicine Specialist and Pediatric Cardiologist Performance

OBJECTIVE

This study compared the accuracy of prenatal congenital heart disease (CHD) diagnosed by maternal-fetal medicine specialists (MFMs) and pediatric cardiologists (PCs), using postnatal cardiac findings as the reference standard.

METHODS

This retrospective analysis at Siriraj Hospital, Bangkok, Thailand, involved 125 pregnancies with fetal CHD diagnosed by MFMs and evaluated by PCs later. Prenatal CHD diagnoses by either MFM or PC were compared with postnatal diagnoses obtained through echocardiography, cardiac surgery/catheterization, or autopsy. Diagnostic accuracy was classified as (A) correct diagnosis, (B) minor differences not impacting clinical management or outcomes, or (C) major differences affecting prognosis or treatment.

RESULTS

Cardiac sonography by MFM achieved diagnostic accuracies of 73.6% (A), 16% (B), and 10.4% (C), while fetal echocardiography by PC resulted in accuracies of 72% (A), 20% (B), and 8% (C). No statistically significant differences were found between MFM and PC in each category (P = .375-.832). The MFMs' accuracy was highest for tetralogy of Fallot (94.4%; 95% CI, 72.7-99.9%) and lowest for right atrial isomerism (71.4%; 95% CI, 29-96.3%) and pulmonary atresia with ventricular septal defect (57.1%; 95% CI, 18.4-90.1%).

CONCLUSIONS

MFMs and PCs demonstrated high and comparable accuracy in prenatal CHD diagnosis. Although PCs tended to outperform MFMs in cases where misdiagnosis could significantly impact neonatal care and outcomes, MFMs can effectively perform primary screening for fetal CHD in all pregnancies. Collaboration with PCs remains essential when fetal CHD is suspected, particularly in complex cases.

Medical Professional Enhancement Using Explainable Artificial Intelligence in Fetal Cardiac Ultrasound Screening

Diagnostic support tools based on artificial intelligence (AI) have exhibited high performance in various medical fields. However, their clinical application remains challenging because of the lack of explanatory power in AI decisions (black box problem), making it difficult to build trust with medical professionals. Nevertheless, visualizing the internal representation of deep neural networks will increase explanatory power and improve the confidence of medical professionals in AI decisions. We propose a novel deep learning-based explainable representation "graph chart diagram" to support fetal cardiac ultrasound screening, which has low detection rates of congenital heart diseases due to the difficulty in mastering the technique. Screening performance improves using this representation from 0.966 to 0.975 for experts, 0.829 to 0.890 for fellows, and 0.616 to 0.748 for residents in the arithmetic mean of area under the curve of a receiver operating characteristic curve. This is the first demonstration wherein examiners used deep learning-based explainable representation to improve the performance of fetal cardiac ultrasound screening, highlighting the potential of explainable AI to augment examiner capabilities.

Detection of Cardiac Structural Abnormalities in Fetal Ultrasound Videos Using Deep Learning

Artificial Intelligence (AI) technologies have recently been applied to medical imaging for diagnostic support. With respect to fetal ultrasound screening of congenital heart disease (CHD), it is still challenging to achieve consistently accurate diagnoses owing to its manual operation and the technical differences among examiners. Hence, we proposed an architecture of Supervised Object detection with Normal data Only (SONO), based on a convolutional neural network (CNN), to detect cardiac substructures and structural abnormalities in fetal ultrasound videos. We used a barcode-like timeline to visualize the probability of detection and calculated an abnormality score of each video. Performance evaluations of detecting cardiac structural abnormalities utilized videos of sequential cross-sections around a four-chamber view (Heart) and three-vessel trachea view (Vessels). The mean value of abnormality scores in CHD cases was significantly higher than normal cases (p < 0.001). The areas under the receiver operating characteristic curve in Heart and Vessels produced by SONO were 0.787 and 0.891, respectively, higher than the other conventional algorithms. SONO achieves an automatic detection of each cardiac substructure in fetal ultrasound videos, and shows an applicability to detect cardiac structural abnormalities. The barcode-like timeline is informative for examiners to capture the clinical characteristic of each case, and it is also expected to acquire one of the important features in the field of medical AI: the development of “explainable AI.”

Strategies for diagnosis of fetal right atrium dilation: based on fetal cardiac anatomy and hemodynamics

BACKGROUND

Fetal right atrium (RA) dilation is frequently detected in routine screenings while it remains a challenge to clarify the reasons. This study aimed to analyze the cardiac anatomy and hemodynamics of fetal RA dilation and the changes of hemodynamic indexes.

METHODS

In the retrospective study, 420 fetuses with RA dilation were included, which were classified into the physiological group (n = 202), volume overload group (n = 142), and the pressure overload group (n = 76). The ratio of right atrium to left atrium (RA/LA) were measured at four-chamber view. Peak velocity of tricuspid regurgitation (V_TR) was recorded in each case, if existed.

RESULTS

The RA/LA ratio in the volume overload group is significantly higher than both the pressure overload group and the physiological group (both P = 0.000) throughout the pregnancy while no difference presents between the pressure overload group and the physiological group (P = 0.694 for 19-31 GW, and P = 0.974 for 32-36 GW, respectively). The V_TR in the pressure overload group (3.29 ± 0.58 m/s) is significantly higher than both the volume overload group (1.85 ± 0.45 m/s, P = 0.000) and the physiological group (0.88 ± 0.45 m/s, P = 0.000). The volume overload group shows a significantly higher V_TR than the physiological group (P = 0.000). In the volume overload group, the ductal contraction/closure shows a significantly higher V_TR than that in the pulmonary valve stenosis/atresia (3.98 ± 0.41 m/s vs. 3.03 ± 0.38 m/s, P = 0.000).

CONCLUSIONS

A strategy proposed herein is useful to clarify the reasons for RA dilatation by systematically assessing fetal hemodynamics, which may facilitate the sonographers to make an accurate diagnosis of congenital heart disease.

Why are congenital heart defects being missed?

OBJECTIVE

Congenital heart defects (CHD) are still missed frequently in prenatal screening programs, which can result in severe morbidity or even death. The aim of this study was to evaluate the quality of fetal heart images, obtained during the second-trimester standard anomaly scan (SAS) in cases of CHD, to explore factors associated with a missed prenatal diagnosis.

METHODS

In this case-control study, all cases of a fetus born with isolated severe CHD in the Northwestern region of The Netherlands, between 2015 and 2016, were extracted from the PRECOR registry. Severe CHD was defined as need for surgical repair in the first year postpartum. Each cardiac view (four-chamber view (4CV), three-vessel (3V) view and left and right ventricular outflow tract (LVOT, RVOT) views) obtained during the SAS was scored for technical correctness on a scale of 0 to 5 by two fetal echocardiography experts, blinded to the diagnosis of CHD and whether it was detected prenatally. Quality parameters of the cardiac examination were compared between cases in which CHD was detected and those in which it was missed on the SAS. Regression analysis was used to assess the association of sonographer experience and of screening-center experience with the cardiac examination quality score.

RESULTS

A total of 114 cases of isolated severe CHD at birth were analyzed, of which 58 (50.9%) were missed and 56 (49.1%) were detected on the SAS. The defects comprised transposition of the great arteries (17%), aortic coarctation (16%), tetralogy of Fallot (10%), atrioventricular septal defect (6%), aortic valve stenosis (5%), ventricular septal defect (18%) and other defects (28%). No differences were found in fetal position, obstetric history, maternal age or body mass index (BMI) or gestational age at examination between missed and detected cases. Ninety-two cases had available cardiac images from the SAS. Compared with the detected group, the missed group had significantly lower cardiac examination quality scores (adequate score (≥ 12) in 32% vs 64%; P = 0.002), rate of proper use of magnification (58% vs 84%; P = 0.01) and quality scores for each individual cardiac plane (4CV (2.7 vs 3.9; P < 0.001), 3V view (3.0 vs 3.8; P = 0.02), LVOT view (1.9 vs 3.3; P < 0.001) and RVOT view (1.9 vs 3.3; P < 0.001)). In 49% of missed cases, the lack of detection was due to poor adaptational skills resulting in inadequate images in which the CHD was not clearly visible; in 31%, the images showed an abnormality (mainly septal defects and aortic arch anomalies) which had not been recognized at the time of the scan; and, in 20%, the cardiac planes had been obtained properly but showed normal anatomy. Multivariate regression analysis showed that the volume of SAS performed per year by each sonographer was associated significantly with quality score of the cardiac examination.

CONCLUSIONS

A lack of adaptational skills when performing the SAS, as opposed to circumstantial factors such as BMI or fetal position, appears to play an important role in failure to detect CHD prenatally. The quality of the cardiac views was inadequate significantly more often in undetected compared with detected cases. Despite adequate quality of the images, CHD was not recognized in 31% of cases. A high volume of SAS performed by each sonographer in a large ultrasound center contributes significantly to prenatal detection. In 20% of undetected cases, CHD was not visible even though the quality of the images was good. © 2019 Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

The construction and application of an ultrasound and anatomical cross-sectional database of structural malformations of the fetal heart

OBJECTIVES

Establish a fetal heart anatomical cross-sectional database that correlates with screening transverse ultrasound images suggested by international professional organizations to detect congenital heart defects.

METHODS

Fetuses with suspected congenital heart defects identified using the following cardiac image sequences obtained from transverse slices beginning from the upper abdomen and ending in the upper thorax were the subjects of this study: (1) four-chamber view, (2) left ventricular outflow tract view, (3) three-vessel right ventricular outflow tract view, and (4) the three-vessel tracheal view. A database of digital two-dimensional images of the transverse sweep was created for fetuses with confirmed congenital heart defects. In addition, using four-dimensional ultrasound spatial-temporal image correlation, selected transverse ultrasound images were acquired as part of the database. Ultrasound-detected congenital heart defects were confirmed postnatally from pathological specimens of the heart and lungs using a cross-sectional technique that mirrored the ultrasound images described above. When anatomical specimens were not available, prenatal ultrasound-detected congenital heart defects were confirmed using postnatal echocardiography and/or following surgery.

RESULTS

The four screening views described in the Methods section identified 160 fetuses that comprised the database. Forty-five datasets consisted of both ultrasound and anatomical cross-sectional images. Thirteen percent (6/45) only had abnormalities of the four-chamber view (eg, endocardial cushion defects). Twenty-four percent (11/45) had abnormalities of the four-chamber view as well as right and left outflow tracts (eg, complex malformations). Of these, 10 of 11 had an abnormal tracheal view. Sixteen percent (7/45) had an abnormal four-chamber view and abnormal right outflow tract (eg, pulmonary stenosis). Thirty-three percent (15/45) had a normal four-chamber view but had abnormal right and left outflow tracts as well as an abnormal tracheal view (eg, tetralogy of Fallot, D-transposition of the great arteries).

CONCLUSIONS

Combining both ultrasound and anatomical imaging may be of assistance in training imagers to recognize cardiovascular pathology when performing the screening examination of the fetal heart.

Barriers to Sonographer Screening for Fetal Heart Defects: A U.S. National Survey

OBJECTIVE

We surveyed obstetric sonographers, who are at the forefront of the screening process to determine how barriers to prenatal cardiac screening impacted screening abilities.

METHODS

We performed a cross-sectional national survey of obstetric sonographers in the United States using a sampling frame from American Registry of Diagnostic Medical Sonography mailing lists. The web survey measured the ability to obtain and interpret fetal heart images. Several cognitive, sociodemographic, and system-level factors were measured, including intention to perform cardiac imaging. Regression and mediation analyses determined factors associated with intention to perform and ability to obtain and interpret cardiac images. Subgroup analyses of sonographers in tertiary versus nontertiary centers were also performed.

RESULTS

Survey response rate either due to noncontact or nonresponse was 40%. Of 480 eligible sonographers, ~30% practiced in tertiary settings. Sonographers had lower intention to perform outflow views compared to 4 chambers. Higher self-efficacy and professional expectations predicted higher odds of intention to perform outflow views (OR 2.8, 95% CI 1.9-4.2 and 1.9, 95% CI 1.1-3.0, respectively). Overall accuracy of image interpretation was 65% (±14%). For the overall cohort and nontertiary subgroup, higher intention to perform outflows was associated with increased accuracy in overall image interpretation. For the tertiary subgroup, self-efficacy and feedback were strongly associated with accuracy.

CONCLUSIONS

We identified several modifiable (some heretofore unrecognized) targets to improve prenatal cardiac screening. Priorities identified by sonographers that are associated with screening success should guide future interventions.

Fetal cardiac abnormalities: Genetic etiologies to be considered

Congenital heart diseases are a common prenatal finding. The prenatal identification of an associated genetic syndrome or a major extracardiac anomaly helps to understand the etiopathogenic diagnosis. Besides, it also assesses the prognosis, management, and familial recurrence risk while strongly influences parental decision to choose termination of pregnancy or postnatal care. This review article describes the most common genetic diagnoses associated with a prenatal finding of a congenital heart disease and a suggested diagnostic process.

Usefulness of color Doppler mode for fetal cardiac ultrasound screening in the second trimester: a study at a single perinatal center

Objectives: To evaluate the usefulness of color Doppler in fetal cardiac ultrasound screening in the second trimester.Methods: Fetuses who underwent ultrasound screening at 18-20 weeks' gestation at Showa University Hospital between 2011 and 2016 were evaluated. After delivery, neonatal congenital heart abnormalities were reviewed and compared with the antenatal ultrasound findings. Since 2014, we have added color Doppler to the routine B mode evaluation of the fetal heart. Congenital heart diseases (CHDs) found antenatally and postnatally were compared before and after protocol alternation. Medical records of all fetuses who underwent ultrasound screening at 18-20 weeks' gestation at Showa University Hospital between 2011 and 2016 were retrospectively reviewed.Results: There were 47 cases of CHDs confirmed postnatally. The detection rates of CHDs were 45.0% (9/20) in 2011-2013 and 55.6% (15/27) in 2014-2016. In 2011-2013, cases with antenatal diagnosis showed obvious abnormal findings of three-vessel view and four-chamber view with the B mode. In 2014-2016, the detection rate of isolated ventricular septal defect (VSD) was elevated from 10 to 42.9% using color Doppler.Conclusions: In this study, color Doppler improved the detection rate of CHDs. Color Doppler could give us additional information on blood flow although the canal or vessel is too small to detect morphological changes in the second trimester. It might be a useful tool for screening of CHDs with stenosis, regurgitation, and shunt that are difficult to detect by only the B mode in the second trimester.

Can echocardiographic screening in the early days of life detect critical congenital heart disease among apparently healthy newborns?

BACKGROUND

Delayed diagnosis of critical congenital heart disease (CCHD) carries a serious risk of mortality, morbidity, and handicap. As echocardiography is commonly used to diagnose congenital heart disease (CHD), echocardiographic investigations in newborns may be helpful in detecting CCHD earlier and with higher sensitivity than when using other screening methods. The present study aimed to evaluate the effectiveness of echocardiographic screening for CCHD in a tertiary care center.

METHODS

A retrospective chart review was conducted among newborns delivered at Hamamatsu University Hospital between June 2009 and May 2016. The study included consecutive newborns who underwent early echocardiographic screening (within the first 5 days of life) performed by pediatric cardiologists, were born at ≥36 weeks of gestation, had a birthweight ≥2300 g, and were cared for in the well-baby nursery. Newborns admitted to the neonatal intensive care unit, as well as those with prenatal diagnosis of CHD and/or clinical symptoms or signs of CHD were excluded. Four CHD outcome categories were defined: critical, serious, clinically significant, and clinically non-significant.

RESULTS

A total of 4082 live newborns were delivered during the study period. Of 3434 newborns who met the inclusion criteria and had complete echocardiography data, 104 (3.0%) were diagnosed as having CHD. Among these, none was initially diagnosed as having critical or serious CHD. Of the 95 newborns who continued follow-up with a cardiologist, 61 (64%) were determined to have non-significant CHDs that resolved within 6 months of life. Review of excluded newborns revealed nine cases of critical or serious CHD; among these newborns, six were diagnosed prenatally and three had some clinical signs of CHD prior to hospital discharge.

CONCLUSIONS

In our tertiary care center, echocardiography screening within the first 5 days of life did not help improve CCHD detection rate in newborns without prenatal diagnosis or clinical signs of CHD. Echocardiographic screening may be associated with increased rate of false-positives (defects resulting in clinically non-significant CHDs) in newborns without prenatal diagnosis or suspicion of CHD.

Neonates with critical congenital heart defects: Impact of fetal diagnosis on immediate and short-term outcomes

Background:

Fetal echocardiography is being increasingly used for prenatal diagnosis of congenital cardiac malformations, but its impact on the neonatal outcomes in low- and middle-income countries is still unknown.

Aims:

The objective of this study is to determine the impact of fetal echocardiography on immediate postnatal and short-term outcome in a tertiary pediatric cardiac center.

Study Design:

This is a prospective study.

Materials and Methods:

One hundred consecutive patients with critical congenital heart defects (CHD) requiring active medical or surgical interventions in the 1^st month of life were included in the study. The detailed history, postnatal examination findings, and fetal echocardiogram report were recorded. They were divided into two groups as antenatally diagnosed and postnatally diagnosed. Pre- and post-procedural variables were compared between the two groups.

Results:

Twenty-nine neonates were diagnosed antenatally while 71 were diagnosed postnatally. Totally, 10 babies (34.5%) among the antenatally diagnosed group were delivered in a tertiary health-care setup. The mean age at presentation was 0 day in the antenatally diagnosed group while 10 days (0–30 days) in the postnatally diagnosed group (P = 0.01). A total of 17 (58.6%) patients in the antenatal group had duct dependent CHD, and 15 (88.2%) of these patients were transported on prostaglandin E1. In comparison, 19/34 (55.9%) patients in the postnatal group were transported on prostaglandin. The pH on admission in the antenatal group was 7.32 ± 0.05 as compared to 7.28 ± 0.05 in the postnatal group (P = 0.0004). There were 4 (5.6%) deaths in the postnatal group during transfer. There was no significant difference in the postoperative variables in both groups.

Conclusions:

Fetal echocardiography identifies patients with complex CHD resulting in better parental counseling, thus facilitating delivery at a tertiary care center and preoperative stabilization. This results in improved preoperative mortality and better stabilization.

Identification of fetal cardiac anatomy and hemodynamics: a novel enhanced screening protocol

Background

Prenatal cardiac screening is of great importance as it contributes to appropriate neonatal management and helps parents to make a decision regarding their pregnancy. The aim of our study was to evaluate the efficiency of a newly proposed screening protocol in the detection of fetal congenital heart disease (CHD).

Methods

This was a prospective study. A total of 52 cases of confirmed CHD fetuses and 248 cases of randomly selected normal fetuses were included in the study. Two sonographers with similar experience performed the cardiac screenings under two different protocols independently. The conventional protocol (Protocol A) paid greater attention to the four-chamber view and the outflow tract views. A 6-month training program was provided to sonographers performing scans under the new protocol (Protocol B), which emphasized systematically evaluating fetal cardiac anatomy and hemodynamics. Color Doppler was mandatory and some ultrasonic signs for special cardiac anomalies were also introduced into this protocol.

Results

Protocol B detected more cardiac anomalies than did Protocol A (96.2 % vs. 61.5 %, P < 0.01). Specifically, Protocol B was superior to Protocol A in detecting cardiac malpositions, abnormal systemic and pulmonary venous connection, right aortic arch, transposition of the great arteries, and congenital corrected transposition of the great arteries. By visualizing flow disturbance and retrograde flow with color Doppler, Protocol B was better than Protocol A in screening valvular associated malformations, such as pulmonary atresia, pulmonary stenosis, tricuspid dysplasia, etc. For the normal fetuses, Protocol B was better than Protocol A in reducing the false-positive detection of septal defects.

Conclusions

The current study introduces an enhanced protocol for fetal cardiac screening, under which the obstetric screening sonographers systematically identify fetal cardiac anatomy and hemodynamics. A short-term training program makes it possible for the screening sonographers to become familiar with the new protocol, and its value has been confirmed due to improvements made in screening efficiency.

Electronic supplementary material

The online version of this article (doi:10.1186/s12884-016-0933-9) contains supplementary material, which is available to authorized users.

Comparing the accuracy of obstetric sonography and fetal echocardiography during pediatric cardiology consultation in the prenatal diagnosis of congenital heart disease

AIM

The diagnostic accuracy of fetal echocardiogram performed by an obstetrician alone and that performed jointly by an obstetrician and pediatric cardiologist for congenital heart disease were compared.

MATERIALS AND METHODS

All cases of suspected fetal congenital heart disease (CHD) referred to the Prenatal Diagnostic Clinic at Tsan Yuk Hospital, Hong Kong during 2006-2011 were reviewed. Prenatal fetal echocardiogram findings were compared with postnatal diagnosis. Cases of incorrect prenatal diagnosis with significant difference in prognosis were analyzed qualitatively.

RESULTS

One hundred and eleven cases of fetal CHD were analyzed. Complete agreement between prenatal and postnatal diagnosis of CHD was observed in 69.4% of cases by fetal echocardiogram performed by obstetrician and 83.8% by fetal echocardiogram performed during pediatric cardiology consultation (P = 0.001). Collaboration with a pediatric cardiologist also improved detection of ductal-dependent cardiac lesions (77.4% vs. 86%, P = < 0.001). Five cases with an incorrect diagnosis were associated with a different prognosis. Three of the cases involved outflow tract abnormalities with incorrect identification of outflow vessels.

CONCLUSION

Collaboration with a pediatric cardiologist can significantly improve the accuracy of prenatal diagnosis of CHD. In particular, joint consultation is associated with significantly better detection of ductal-dependent lesions. Outflow tract abnormalities remain a diagnostic challenge in prenatal diagnosis. Incorrect identification of outflow tract vessels was the major cause of incorrect diagnosis in our series.

Screening of congenital heart disease in the second trimester of pregnancy: current knowledge and new perspectives to the clinical practice

OBJECTIVE

Congenital heart diseases are common in foetuses, with an incidence greater than six times that of chromosomal abnormalities; however, experts in cardiac anatomy have evaluated only the foetuses of pregnant women with increased risk for congenital heart disease. Over the years, it has become clear that congenital heart disease occur in foetuses of low-risk women. In the mid-1980s, a proposal to expand the assessment of cardiac anatomy was presented to obstetricians in order to improve prenatal screening. With the aim to systematise and improve the diagnosis of congenital heart disease in foetuses, the International Society of Ultrasound in Obstetrics and Gynecology established an ultrasound heart examination guideline. In this review, we have described the important features of this guideline and discussed the applications of this tool in clinical practice.

METHODS

We performed a literature search of the National Library of Medicine for publications released between 2000 and 2012; we used search terms pertinent to congenital heart disease, such as foetal echocardiography, foetal heart and cardiac screening examination.

RESULTS

The guidelines serve as a standard and help to systematise the screening for congenital heart diseases, but we think that some topics may be added to design the most appropriate screening method. However, we cannot expand the topics to be evaluated in this examination without good training of sonographers who undergo this screening.

CONCLUSION

Although the screening standardisation is a good tool to be used in day-to-day practice, the increment of aortic and ductal archs and colour Doppler to heart screening could be useful to detect further cardiac defects.

The new 3D/4D based spatio-temporal imaging correlation (STIC) in fetal echocardiography: a promising tool for the future

Congenital heart disease is the commonest congenital anomaly. It is much more common than chromosomal malformations and spinal defects. Its estimated incidence is about 4-13 per 1000 live births. Congenital heart disease is a significant cause of fetal mortality and morbidity. Antenatal diagnosis of congenital heart disease is extremely difficult and requires extensive training and expertise. The detection rate of congenital heart disease is very variable and it ranged from 35 to 86% in most studies. In the light of the above, the introduction of the new 3D/4D based spatio-temporal Image Correlation (STIC) is highly welcomed to improve antenatal detection of congenital heart disease. STIC is an automated device incorporated into the ultrasound probe and has the capacity to perform slow sweep to acquire a single 3-dimensional (3D) volume. This acquired volume is composed of a great number of 2-dimension (2D) frames. This volume can be analyzed and reanalyzed as required to demonstrate all the required cardiac views. It also provides the examiner with the ability to review all images in a looped cine sequence. This technology has the ability to improve our ability to examine the fetal heart in the acquired volume and decrease examination time. Using this technique you can share the information and consult colleagues both at your clinical sitting or remotely using the internet.

Accuracy, agreement, and reliability of fetal cardiac measurements using 4-dimensional spatiotemporal image correlation

OBJECTIVES

The purpose of this study was to evaluate the accuracy, agreement, and reliability of 4-dimensional sonography using spatiotemporal image correlation (STIC) in fetal cardiac measurements during the second and third trimesters.

METHODS

Four-dimensional cardiac STIC volumes were acquired from 150 low-risk singleton pregnancies at gestational ages of 18 to 38 weeks. A total of 11 dimensions of the fetal heart and great vessels were analyzed by two different observers. Accuracy was assessed by comparing the measurements acquired by 4-dimensional STIC with those determined by 2-dimensional echocardiography by calculating the mean error and mean percent error and depicted by Bland-Altman plots. Absolute agreement and reliability of STIC-based measurements were evaluated on the basis of an intraclass correlation coefficient (ICC).

RESULTS

For STIC-based measurements of cardiac dimensions, good accuracy was achieved by the two experienced observers (mean percent error, -3.10% to 0.87% for observer A; -2.49% to -0.33% for observer B), and absolute agreement was almost perfect (ICC, 95% confidence interval, 0.916-0.993 for observer A; 0.957-0.990 for observer B). Interobserver ICCs among the two observers were between 0.909 and 0.990 (95% confidence interval), whereas intraobserver ICCs for observer A were between 0.894 and 0.989, and those for observer B were between 0.893 and 0.985, showing no significant differences in the reliability of SITC with regard to observers.

CONCLUSIONS

Four-dimensional sonography with STIC is a feasible and accurate method for fetal cardiac dimension measurements in the second and third trimesters. It is in good agreement with 2-dimensional echocardiography and can be performed by different observers.

Results of early foetal echocardiography and cumulative detection rate of congenital heart disease

OBJECTIVE

The aim of this study is to evaluate the cumulative detection rate of foetal echocardiography during gestation and in the early neonatal period, with a special emphasis on early foetal echocardiography.

METHODS

We conducted a retrospective survey of all singleton pregnancies from 1993 to 2007, with complete sequential echocardiography from 11 plus 0 to 13 plus 6 weeks of gestation. It was mandatory to have at least one foetal echocardiography in the second or third trimester and one postnatally.

RESULTS

Our study included 3521 pregnancies, in which 77 cases were diagnosed with congenital heart disease. Of them, 66 were detected in the first trimester - 11 plus 0 to 11 plus 6 weeks: 22 cases; 12 plus 0 to 12 plus 6 weeks: 23 cases; 13 plus 0 to 13 plus 6 weeks: 21 cases - with an 85.7% detection rate of congenital heart disease in early foetal echocardiography. In the second trimester, seven cases were found, with a detection rate of 9.1%. The third trimester reported two cases, with a detection rate of 2.6%. Postnatally, two (2.6%) cases were detected. The overall in utero detection rate of congenital heart disease was 97.4%.

CONCLUSIONS

Foetal echocardiography performed at the time of anomaly screening in the first trimester results in high detection rates of congenital heart disease. Cardiac pathology may evolve, and further examinations at later stages of pregnancy could improve the detection rate of congenital heart disease.

Scan the fetal heart by real-time three-dimensional echocardiography with live xPlane imaging

OBJECTIVE

To describe the methodology of live xPlane imaging in the visualization of the fetal heart in detail.

METHODS

Fifty-one consecutive pregnant women with singleton pregnancies were imaged to display four screening sections of the fetal heart, the four-chamber view, the left outflow tract view (LVOT), the right outflow tract view (RVOT), and the three-vessel and trachea view (3VT), using live xPlane imaging. The methodology of how to visualize the screening planes was described in detail. We used two methods to image the fetal heart with live xPlane imaging: one uses the four-chamber view as the starting plane and the other uses the longitudinal view of fetal upper thorax as the starting plane.

RESULTS

When using the four-chamber view as the starting plane, the visualization rate of LVOT, RVOT, and 3VT was 94.1% (48/51), 100% (51/51), and 98.0% (50/51), respectively. When using the longitudinal view as the starting plane, the visualization rate of four-chamber view, LVOT, RVOT, and 3VT was 100% (51/51), 100% (51/51), 41.2% (21/51), and 100% (51/51), respectively.

CONCLUSIONS

Live xPlane imaging can be used to visualize the screening views of the fetal heart, and potentially may be a useful tool for the assessment and diagnosis of fetal congenital heart diseases.

Impact of audit of routine second-trimester cardiac images using a novel image-scoring method

OBJECTIVE

To assess the impact of using an objective scoring method to audit cardiac images obtained as part of the routine 21-23-week anomaly scan.

METHODS

A prospective audit and re-audit (6 months later) were conducted on cardiac images obtained by sonographers during the routine anomaly scan. A new image-scoring method was devised based on expected features in the four-chamber and outflow tract views. For each patient, scores were awarded for documentation and quality of individual views. These were called 'Documentation Scores' and 'View Scores' and were added to give a 'Patient Score' which represented the quality of screening provided by the sonographer for that particular patient (maximum score, 15). In order to assess the overall performance of sonographers, an 'Audit Score' was calculated for each by averaging his or her Patient Scores. In addition, to assess each sonographer's performance in relation to particular aspects of the various views, each was given their own 'Sonographer View Scores', derived from image documentation and details of four-chamber view (magnification, valve offset and septum) and left and right outflow tract views. All images were scored by two reviewers, jointly in the primary audit and independently in the re-audit. The scores from primary and re-audit were compared to assess the impact of feedback from the primary audit.

RESULTS

Eight sonographers participated in the study. The median Audit Score increased significantly (P < 0.01), from 10.8 (range, 9.8-12.4) in the primary audit to 12.4 (range, 10.4-13.6) in the re-audit. Scores allocated by the two reviewers in the re-audit were not significantly different (P = 0.08).

CONCLUSION

Objective scoring of fetal heart images is feasible and has a positive impact on the quality of cardiac images acquired at the time of the routine anomaly scan. This audit tool has the potential to be applied in every obstetric scanning unit and may improve the effectiveness of screening for congenital heart defects.

Evaluation of referral indications for fetal echocardiography in Beijing

OBJECTIVES

This study was conducted to evaluate the referral indications for fetal echocardiography (FE) in a tertiary center and to determine which indications were significantly associated with prenatal detection of congenital heart disease (CHD).

METHODS

The medical records of 1425 consecutive women who underwent second- and third-trimester FE at the Ultrasound Center of Beijing Obstetrics and Gynecology Hospital from March 2003 to December 2007 were reviewed. Referral indications, FE diagnoses, and pregnancy outcomes were collected. Univariate and multivariate logistic regression analyses were performed to identify those referral indications associated with prenatal detection of CHD.

RESULTS

In 126 patients (8.8%), CHD was detected prenatally and confirmed postnatally. Logistic regression analysis showed that abnormal cardiac views and extracardiac malformation findings (especially a single umbilical artery) on second-trimester ultrasound screening were found to have significantly more CHD (P < .001). The adjusted odds ratios were 15.2 (95% confidence interval, 9.85-23.45) and 6.78 (95% confidence interval, 2.38-19.27), respectively.

CONCLUSIONS

Abnormal cardiac views and extracardiac malformation findings on second-trimester ultrasound screening were significantly associated with prenatal detection of CHD.

Potential pitfalls and methods of improving in utero diagnosis of transposition of the great arteries, including the baby bird's beak image

OBJECTIVE

The goal of this study was to analyze our recent experience with fetuses with transposition of the great arteries (TGA) to identify potential pitfalls and possible methods to better detect conotruncal anomalies such as TGA.

METHODS

We analyzed all nonreferral obstetric ultrasound examinations in which we performed basic, targeted, or formal fetal echocardiography with a newborn diagnosis of TGA.

RESULTS

Nine neonates had TGA. Five of these cases were diagnosed prenatally, and 4 of these had complex congenital heart abnormalities. In these 4 cases, there were abnormalities in the cardiac axis (n = 3), abnormal valves or ventricular size (n = 2), and ventricular septal defects (n = 3) that were detected on the 4-chamber view of the heart. In all cases that were not detected prenatally, both prospective and retrospective reviews of the 4-chamber heart appeared normal. The prospective analyses of the outflow tracts were all interpreted as normal, whereas the retrospective review showed subtle abnormalities such as the "baby bird's beak" image. In review of these cases, there was failure to show the "crisscross" relationship of the outflow tracts. In 1 case, 5 short axis views of the heart, retrospectively showed the artery originating from the left ventricle and bifurcated, representing the pulmonary artery.

CONCLUSIONS

Transposition of the great arteries may be associated with complex cardiac disease that could be detected on the 4-chamber view of the heart. When the 4-chamber view is normal, it is important to identify the crisscross relationship of the outflow tracts. If this is not done, it is important to document that the pulmonary artery bifurcates and originates from the right ventricle. Five short axis views of the heart may be helpful to detect conotruncal abnormalities.

Does fetal diagnosis make a difference?

Fetal echocardiography has clearly made a difference in the world of pediatric cardiology today. It has taught us much about the natural history of fetal cardiac disease, and with ongoing collaborative studies, it should continue to enhance our knowledge base. Fetal echocardiography has enabled us to identify potential candidates for fetal cardiac intervention and has promoted the development of an exciting new discipline within pediatric cardiology. We hope that the recognition of critical congenital heart disease in utero improves the long-term outcome of our patients, including neurodevelopmental outcome and quality of life.