Simplifying ultrasound assessment of the fetal heart: Incorporating the complete Three Vessel View into routine screening

Increased Pulmonary-Aortic Interspace in Fetal Right Aortic Arch: A Matched Case-Control Study

INTRODUCTION

The prenatal detection rate of a right aortic arch (RAA) has increased with the implementation of the three-vessel view (3VV) to the second-trimester anomaly scan formed by the pulmonary artery (PA), aorta (Ao), and superior vena cava (SVC). We examined the value of measuring the distance between PA and Ao in the 3VV in cases with an RAA.

METHODS

We conducted a case-control study in which fetuses with an isolated RAA were matched to 3 healthy controls. Using 3VV images, the distances between PA, Ao, and SVC were measured and the ratio between PA to Ao (PAAo) distance and Ao to SVC (AoSVC) distance was calculated.

RESULTS

Fifty-four RAA cases and 162 matched controls were included. The mean absolute distance PAAo was 3.1 mm in cases and 1.8 mm in controls (p < 0.001), and the mean PAAo/AoSVC ratio was 2.9 and 1.4, respectively (p < 0.001). The ROC curve of PAAo/AoSVC ratio showed a cut-off point of 1.9 with sensitivity and specificity over 87% for the diagnosis of RAA.

CONCLUSIONS

The pulmonary-aortic interspace and the PAAo/AoSVC ratio were significantly larger for RAA cases as compared to controls. If an increased pulmonary-aortic interspace is observed, a PAAo/AoSVC of ≥1.9 can be helpful in the diagnosis of an RAA.

Automatic echocardiographic anomalies interpretation using a stacked residual-dense network model

Echocardiographic interpretation during the prenatal or postnatal period is important for diagnosing cardiac septal abnormalities. However, manual interpretation can be time consuming and subject to human error. Automatic segmentation of echocardiogram can support cardiologists in making an initial interpretation. However, such a process does not always provide straightforward information to make a complete interpretation. The segmentation process only identifies the region of cardiac septal abnormality, whereas complete interpretation should determine based on the position of defect. In this study, we proposed a stacked residual-dense network model to segment the entire region of cardiac and classifying their defect positions to generate automatic echocardiographic interpretation. We proposed the generalization model with incorporated two modalities: prenatal and postnatal echocardiography. To further evaluate the effectiveness of our model, its performance was verified by five cardiologists. We develop a pipeline process using 1345 echocardiograms for training data and 181 echocardiograms for unseen data from prospective patients acquired during standard clinical practice at Muhammad Hoesin General Hospital in Indonesia. As a result, the proposed model produced of 58.17% intersection over union (IoU), 75.75% dice similarity coefficient (DSC), and 76.36% mean average precision (mAP) for the validation data. Using unseen data, we achieved 42.39% IoU, 55.72% DSC, and 51.04% mAP. Further, the classification of defect positions using unseen data had approximately 92.27% accuracy, 94.33% specificity, and 92.05% sensitivity. Finally, our proposed model is validated with human expert with varying Kappa value. On average, these results hold promise of increasing suitability in clinical practice as a supporting diagnostic tool for establishing the diagnosis.

Abnormalities of the Width of the Four-Chamber View and the Area, Length, and Width of the Ventricles to Identify Fetuses at High-Risk for D-Transposition of the Great Arteries and Tetralogy of Fallot

OBJECTIVES

The prenatal detection of D-Transposition of the great arteries (D-TGA) and tetralogy of Fallot (TOF) has been reported to be less than 50% to as high as 77% when adding the outflow tracts to the four-chamber screening protocol. Because many examiners still struggle with the outflow tract examination, this study evaluated whether changes in the size and shape of the heart in the 4CV as well as the ventricles occurred in fetuses with D-TGA and TOF could be used to screen for these malformations.

METHODS

Forty-four fetuses with the pre-and post-natal diagnosis of D-TGA and 44 with TOF were evaluated between 19 and 36 weeks of gestation in which the 4CV was imaged. Measurements of the end-diastolic width, length, area, and global sphericity index were measured for the four-chamber view and the right and left ventricles. Using z-score computed values, logistic regression was performed between the 88 study and 200 control fetuses using the hierarchical forward selection protocol.

RESULTS

Logistic regression identified 10 variables that correctly classified 83/88 of fetuses with TOF and TGA, for a sensitivity of 94%. Six of 200 normal controls were incorrectly classified for a false-positive rate of 3%. The area under the receiver operator classification curve was 98.1%. The true positive rate for D-TGA was 93.2%, with a false-negative rate to 6.8%. The true positive rate for TOF was 95.5%, with a false negative rate of 4.5%.

CONCLUSIONS

Measurements of the 4CV and of the RV and LV may help identify fetuses at risk for D-TGA or TOF.

Maternal paracetamol intake and fetal ductus arteriosus constriction/closure: comprehensive signal evaluation using the Austin Bradford Hill criteria

PURPOSE

Acetaminophen (APAP) is available over-the-counter and widely regarded as safe for use in pregnancy. APAP has been used to close a persistently patent ductus arteriosus. Fetal constriction/closure of the ductus arteriosus (FCCDA), of public health interest given the drug's widespread use during pregnancy, is being monitored globally, including by the European Medicines Agency Pharmacovigilance Risk Assessment Committee. Our objective was to share a comprehensive signal evaluation of FCCDA with in utero APAP exposure to determine if the totality of evidence is sufficiently more consistent with one of the following two possibilities: (1) APAP never contributes to FCCDA (null hypothesis or H_O) versus (2) APAP may in some cases be at least a contributory cause of in utero DA narrowing (alternative hypothesis or H_A) to justify risk communication.

METHODS

To assess the relative support for H_O versus H_A, we synthesize and interpret within an Austin Bradford Hill criteria framework a comprehensive, cross-disciplinary set of published information and de novo analysis, including toxicology, epidemiology, clinical pharmacology, and clinical and quantitative pharmacovigilance analysis of spontaneous reports.

RESULTS

While residual uncertainty remains, the totality of information is more compatible with H_A than H₀, to the extent that it is reasonably possible that APAP may sometimes be at least a contributory cause of FCCDA.

CONCLUSION

It is reasonably possible that APAP may sometimes be at least a contributory cause of FCCDA, and this should therefore be communicated to stakeholders.

TRIAL REGISTRATION

CLINICALTRIALS.

GOV REGISTRATION

NOT APPLICABLE.

Extraction of foetal ECG from abdominal ECG by nonlinear transformation and estimations

BACKGROUND AND OBJECTIVE

This paper proposes a simple yet effective method for the extraction of foetal ECG from abdominal ECG which is necessary due to similar spatial and temporal content of mother and foetal ECG.

METHODS

The proposed algorithm for extraction of foetal ECG (fECG) from abdominal signal uses single channel. Pre-processing of abdominal ECG (abdECG) has been done to eliminate noise and condition the signal. The maternal ECG R-peaks have been detected based on thresholding, first order Gaussian differentiation and zero cross detection on pre-processed signal. Having identified R-peaks and pre-processed signal as base, using Maximum Likelihood Estimation, one beat including QRS complex morphology of maternal ECG (mECG) has been constructed. Extraction of maternal ECG from abdECG is done based on the constructed beat, R-peak locations and its corresponding QRS complex of abdECG. Extracted mECG has been cancelled from abdECG. This results in foetal ECG with residual noise. The noise has been reduced by Polynomial Approximation and Total Variation (PATV) to improve SNR. This approach ensures no loss of partially or completely overlapped fECG signals due to mECG removal. The algorithm is tested on three database namely daISy (DB_I), Physiobank challenge 2013 (DB_II) and abdominal and direct foetal ECG database (adfecgdb) of Physiobank (DB_III).

RESULTS

The algorithm detected no false positives or false negatives with certain channel for DB_I, DB_II and DB_III which shows that the proposed algorithm can achieve good performance. Overall accuracy and sensitivity of the system is 98.53% and 100% for DB_I. Best accuracy and sensitivity of 97.77% and 98.63% are obtained for DB_II. Best accuracy of 92.41% and sensitivity of 93.8% are obtained for DB_III. Correlation coefficient between actual foetal heart rate (fHR) and estimated fHR of 0.66 for DB_II and 0.59 for DB_III is obtained. The method has obtained overall F1 score of 99.25% for DB_I, 96.04% for DB_II and 94.25% for DB_III. It has obtained a best MSE of fHR and overall MSE of R-R interval which is 10.8bpm² and 2.2 ms for DB_II, 12bpm² and 2.14 ms for DB_III.

CONCLUSION

The results for different public databases show that the proposed method is capable of providing good results. The foetal QRS, R-peaks and R-R intervals have also been obtained in this method. Thus, it gives a significant contribution in the required area of research.

Single centre audit of early impact of inclusion of the three vessel and trachea view in obstetric screening

Detection rates of congenital cardiac malformations have traditionally remained low. The NHS Fetal Anomaly Screening Programme (FASP) aims to increase these detection rates for various reasons, including influencing perinatal management and aiding parental decision making. The inclusion of the three vessel view and trachea (3VT) view in 2015 aimed to improve detection rates of arch abnormalities in particular. This study evaluated the early impact of the new initiative at one NHS Trust. Departmental screen-positive rates were compared for a full year before and after implementation. Referrals to, and opinions of, the foetal medicine unit (FMU) were assessed; as were undetected congenital heart defects for the two time periods. Compared with the pre-implementation (pre-3VT) period, the number of completed anomaly scans performed after implementation (post-3VT) increased by 3% and the number of FMU referrals increased by 625%. Departmental screen-positive rates for cardiac abnormalities increased from 40% (pre-3VT) to 91% (post-3VT). Over half (52%) of the FMU referrals were made due to a suspected abnormal 3VT view. Early evaluation of 3VT implementation at this NHS Trust indicates that it has been a success. Departmental screen-positive rates for congenital cardiac malformations have risen. However, this performance has come at a cost: Some abnormalities now being detected, such as loose vascular ring and PLSVC, are frequently asymptomatic and likely to be clinically insignificant. The implementation of 3VT achieves the aims of FASP but may begin to exceed what is expected from a low risk population screening programme.