Fetal cardiac dimensions at 14-40 weeks' gestation obtained using cardio-STIC-M

Canine fetal echocardiography: correlations for the analysis of cardiac dimensions

The aim of this study was to develop regression models for correlation of canine fetal heart development with body size to characterize normal development or suggest cardiac anomalies. Twenty clinically healthy pregnant bitches, either brachycephalic and non-brachycephalic, were examined ultrasonographically. Transabdominal fetal echocardiography was conducted every 4 days from the beginning of cardiac chambers differentiation until parturition. Ten cardiac parameters were measured: length, width and diameter of the heart; heart area; left and right ventricular dimensions; left and right atrial dimensions; and aortic and pulmonary artery diameter. Femoral length, biparietal diameter and abdominal cross-sectional area were also recorded. Regression equations were developed for each parameter of fetal body size, and linear and logarithmic models were compared. The model with the highest correlation coefficient was chosen to produce equations to calculate relative dimensions based on the correlations. Only the left-ventricular chamber differed between the two racial groups. Biparietal diameter was the independent parameter that produced the highest correlation coefficient for the most fetal cardiac dimensions, although good correlations were also observed using femoral length and abdominal cross-sectional area. Heart width and heart diameter were used as surrogates of cardiac development, as these measurements showed the best statistical correlation. Quantitative evaluation of fetal cardiac structures can be used to monitor normal and abnormal cardiac development.

Hemodynamic studies of isolated absent ductus venosus

OBJECTIVE

The objective of this article is to evaluate hemodynamic changes among fetuses with isolated absent ductus venosus (IADV) diagnosed by prenatal ultrasonography.

PATIENTS AND METHODS

Fetuses with prenatal diagnosis of IADV were recruited and followed. Hemodynamic assessment was performed in all cases, including measurement of cardiac dimensions, shortening fraction, myocardial performance index, preload index in the inferior vena cava and the presence of venous pulsations in the umbilical vein (UV).

RESULTS

Nine fetuses of IADV were assessed, including six cases with extra-hepatic UV drainage and three with intra-hepatic drainage. All fetuses with extra-hepatic UV drainage showed an elevated preload index in the inferior vena cava, venous pulsations in the UV and cardiomegaly. Of them, four had hydrops, two showed poor cardiac function and three resulted in perinatal mortality. Three cases with intra-hepatic drainage had continuous flow in the UV, normal in all hemodynamic parameters and all survived.

CONCLUSION

Hemodynamic assessment of fetuses with IADV was helpful in predicting the development of hydrops and perinatal mortality. The poor prognostic factors included cardiac overload, cardiomegaly, poor myocardial performance, increased preload, the presence of venous pulsations and extra-hepatic UV drainage. © 2015 John Wiley & Sons, Ltd.

Analysis of etiology, chromosome and prognosis for small left heart system development in 69 fetuses

OBJECTIVE

To provide a basis for evaluating the prognosis of small left heart system development in fetuses, we analyzed its related factors.

METHODS

The fetal echocardiogram was performed in 3859 pregnant women, and then small left heart system development was identified in 69 fetuses. The data of prenatal and postnatal echocardiograms, postnatal cardiac surgical treatment, chromosome and autopsy after induced labor were analyzed in the 69 fetuses.

RESULTS

Except 1320 cases losing follow-up, 2539 cases had complete data. Among the 2539 cases, small left heart system development was identified in 69 fetuses. Of the 69 fetuses, 12 had hypoplastic left heart syndrome, 20 premature closure of foramen ovale, 13 total anomalous pulmonary venous drainage, 2 common pulmonary vein lumen atresia, 21 aortic coarctation or interruption and 1 right pulmonary hypoplasia. Among the 69 fetuses, chromosome abnormality was found in 7.

CONCLUSION

There are many etiological factors causing small left heart system development. The prognosis is poor in the fetuses with hypoplastic left heart syndrome, common pulmonary vein lumen atresia, pulmonary hypoplasia, other malformations or/and chromosome abnormality. Fetal echocardiography combined with chromosome examination can provide important bases for making diagnosis and evaluating the prognosis regarding small left heart system development.

Cardio-STIC (spatio-temporal image correlation) as genetic ultrasound of fetal Down syndrome

OBJECTIVE

To evaluate efficacy of cardio-STIC in detection of fetal Down syndrome.

METHODS

Cardio-STIC volume datasets (VDS) were prospectively collected from women during 16-22 weeks, consisting of 40 VDS acquired from fetuses with Down syndrome and 400 VDS from normal fetuses. All VDS were blindly analyzed.

RESULTS

Between both groups, most dimensions were comparable but the right-sided dimensions were significantly greater in fetuses with Down syndrome. Interestingly, shortening fraction was also significantly higher in affected fetuses. Right-to-left disproportion and shortening fraction were used as cardiac markers as well as other eight structural markers to predict fetal Down syndrome. Tricuspid regurgitation had highest sensitivity (30%); followed by VSD (27.5%), right-to-left disproportion (20.0%), and echogenic intra-cardiac foci (EIF; 17.5%). If the test was considered positive in case of the presence of any cardiac marker, cardio-STIC had a detection rate of 72.5% and false-positive rate of 19.5%. Likelihood ratio of each marker for modifying priori risk was also provided.

CONCLUSION

Cardio-STIC as genetic ultrasound for Down syndrome had a detection rate of about 70% and false-positive rate 20%. Cardio-STIC analysis can be helpful in estimation of fetal risk for Down syndrome and counseling when the prenatal diagnosis of the syndrome is made.

Fetal myocardial wall area: constructing a reference range by means of spatiotemporal image correlation in the rendering mode

OBJECTIVE

To establish the reference range of the myocardial wall area in the fetus using three-dimensional ultrasound in the rendering mode.

METHODS

A prospective, cross-sectional study including 371 singleton, uncomplicated pregnancies at 20 weeks 0 day to 33 weeks 6 days of gestation was carried out. Cardiac volumes were obtained using spatiotemporal image correlation (STIC) at the level of the four-chamber view. The end-diastolic myocardial area of the both ventricles was measured manually. The intraclass correlation coefficient (ICC) was used to assess intra- and interobserver concordance.

RESULTS

The mean myocardial area of the fetal right ventricular (RV) wall ranged from 0.86 ± 0.23 cm(2) at 20 weeks 0 day to 2.75 ± 0.69 cm(2) at 33 weeks 6 days of gestation. The mean myocardial area of the fetal left ventricular (LV) wall ranged from 0.82 ± 0.20 cm(2) at 20 weeks 0 day to 2.49 ± 0.59 cm(2) at 33 weeks 6 days of gestation. In addition, intra- and interobserver concordance for the myocardial area of the RV and LV walls was good, with ICC values of 0.94, 0.95, 0.85, and 0.93, respectively.

CONCLUSIONS

The reference range for the myocardial area of the RV and LV walls was determined by cardio-STIC in the rendering mode at 20 weeks 0 day to 33 weeks 6 days of gestation, with good concordance between values.

Screening for hemoglobin Bart's disease among fetuses at risk at mid-pregnancy using the fetal cardiac diameter to biparietal diameter ratio

Background

All sonomarkers used to screen for fetal hemoglobin (Hb) Bart’s disease need high expertise, preventing them from being widely used. Fetal cardiac diameter to biparietal diameter (C/B) ratio is a simple marker which has never been evaluated for its effectiveness. Therefore, we conducted this study to evaluate the effectiveness of C/B ratio in predicting fetal Hb Bart’s disease among fetuses at risk.

Methods

Fetuses at risk of Hb Bart’s disease scheduled for diagnostic cordocentesis at 18 to 22 weeks of pregnancy were prospectively enrolled. All underwent ultrasound for fetal biometry and cardio-STIC acquisition for subsequent off-line analysis. Cardio-STIC volume datasets (VDS) were analyzed for cardiac diameter measurement and C/B ratio was calculated by the authors who did not know the fetal diagnosis. Final diagnosis of Hb Bart’s disease was based on fetal blood Hb typing.

Results

Of 131 pregnancies enrolled to the study, 11 were excluded because of poor quality VDS. The remaining 120 were available for analysis. C/B ratio was significantly higher in the fetuses with Hb Bart’s disease than that in the unaffected ones (53.16% vs 41.68%, P < 0.001). C/B ratio could detect fetuses with Hb Bart’s disease with sensitivity of 91.5% and specificity of 77.6% (AUC ROC 0.929), using a cut-off point of greater than 45%.

Conclusions

Among fetuses at risk, C/B ratio measurement at mid-pregnancy, using cut-off point of 45%, could effectively differentiate fetuses with Hb Bart’s disease from unaffected fetuses.

Echocardiographic assessment of embryonic and fetal mouse heart development: a focus on haemodynamics and morphology

Background. Heart development is a complex process, and abnormal development may result in congenital heart disease (CHD). Currently, studies on animal models mainly focus on cardiac morphology and the availability of hemodynamic data, especially of the right heart half, is limited. Here we aimed to assess the morphological and hemodynamic parameters of normal developing mouse embryos/fetuses by using a high-frequency ultrasound system. Methods. A timed breeding program was initiated with a WT mouse line (Swiss/129Sv background). All recordings were performed transabdominally, in isoflurane sedated pregnant mice, in hearts of sequential developmental stages: 12.5, 14.5, and 17.5 days after conception (n = 105). Results. Along development the heart rate increased significantly from 125 ± 9.5 to 219 ± 8.3 beats per minute. Reliable flow measurements could be performed across the developing mitral and tricuspid valves and outflow tract. M-mode measurements could be obtained of all cardiac compartments. An overall increase of cardiac systolic and diastolic function with embryonic/fetal development was observed. Conclusion. High-frequency echocardiography is a promising and useful imaging modality for structural and hemodynamic analysis of embryonic/fetal mouse hearts.

Real-time three-dimensional foetal echocardiography using a new transabdominal xMATRIX array transducer

BACKGROUND

Foetal echocardiography has been used to diagnose congenital heart disease. However, conventional echocardiography can only display two-dimensional (2D) structural images of the intricate three-dimensional (3D) foetal heart.

AIM

The purpose of this study was to report the first use of a new transabdominal xMATRIX array transducer and to describe its ability to perform all 3D modalities: intelligent spatiotemporal image correlation (iSTIC) acquisition, xPlane imaging and 3D surface imaging.

METHODS

Eighty foetuses without congenital heart disease were included consecutively, with a gestational age between 20 and 37 weeks. 2D and 3D scans were performed with a transabdominal xMATRIX array transducer. Cardiac-STIC volume datasets were acquired and postprocessed with new automatic software (the 'Fetal Heart Navigator').

RESULTS

A total of 224 iSTIC acquisitions were performed (mean time for each, 2 seconds). Only 78 iSTIC acquisitions (35%) were able to detect the ductal arch automatically. 'Fetal Heart Navigator' feasibility varied according to foetal position, including the descending aorta. Live xPlane imaging had excellent feasibility regardless of foetal position; using rotation, lateral and vertical tilts, all cardiac structures were identified from a unique reference plane. Live 3D surface imaging had variable feasibility depending on the target structure. Only 10% of the volume dataset offered comprehensive imaging of intracardiac views.

CONCLUSION

The new xMATRIX transabdominal transducer allows a multimodality approach to the foetal heart. Further studies that include foetuses with cardiac malformations are required.

Comparison of fetal cardiac spatiotemporal image correlation segmental analysis between cardiac- and body-based scrolling

OBJECTIVES

The purpose of this study was to compare success rates for depiction of the 5 typical transverse planes in the fetal upper thorax between cardiac- and body-based scrolling techniques.

METHODS

Spatiotemporal image correlation volume data sets acquired at the 4-chamber view level were obtained from low-risk singleton pregnancies with healthy fetuses. Each data set was analyzed by the authors using both cardiac- and body-based techniques. With the cardiac-based technique, the exact 4-chamber view was first identified as an initial plane before scrolling, whereas with the body-based technique, a volume data set was first manipulated to get the fetal orientation in the exact dorsal supine position as an initial plane. In both techniques, the volumes were then scrolled through the upper thorax to identify the standard planes, including the 4-chamber, 5-chamber, 3-vessel, 3-vessel and trachea, and aortic arch views.

RESULTS

An analysis of 50 volume data sets to evaluate intraobserver and interobserver variability in the success rates for the 4-chamber, 5-chamber, 3-vessel, 3-vessel and trachea, and aortic arch views showed good agreement. In an analysis of 296 separate data sets, cardiac-based scrolling was associated with significantly higher success rates than body-based scrolling in all standard planes (P < .05).

CONCLUSIONS

Cardiac-based scrolling resulted in higher success rates for obtaining the standard spatiotemporal image correlation planes than body-based scrolling. Therefore, examiners in the early part of the learning curve should be encouraged to first identify a perfect 4-chamber view at the start of an examination.

Fetal Intelligent Navigation Echocardiography (FINE): a novel method for rapid, simple, and automatic examination of the fetal heart

OBJECTIVE

To describe a novel method (Fetal Intelligent Navigation Echocardiography (FINE)) for visualization of standard fetal echocardiography views from volume datasets obtained with spatiotemporal image correlation (STIC) and application of 'intelligent navigation' technology.

METHODS

We developed a method to: 1) demonstrate nine cardiac diagnostic planes; and 2) spontaneously navigate the anatomy surrounding each of the nine cardiac diagnostic planes (Virtual Intelligent Sonographer Assistance (VIS-Assistance®)). The method consists of marking seven anatomical structures of the fetal heart. The following echocardiography views are then automatically generated: 1) four chamber; 2) five chamber; 3) left ventricular outflow tract; 4) short-axis view of great vessels/right ventricular outflow tract; 5) three vessels and trachea; 6) abdomen/stomach; 7) ductal arch; 8) aortic arch; and 9) superior and inferior vena cava. The FINE method was tested in a separate set of 50 STIC volumes of normal hearts (18.6-37.2 weeks of gestation), and visualization rates for fetal echocardiography views using diagnostic planes and/or VIS-Assistance® were calculated. To examine the feasibility of identifying abnormal cardiac anatomy, we tested the method in four cases with proven congenital heart defects (coarctation of aorta, tetralogy of Fallot, transposition of great vessels and pulmonary atresia with intact ventricular septum).

RESULTS

In normal cases, the FINE method was able to generate nine fetal echocardiography views using: 1) diagnostic planes in 78-100% of cases; 2) VIS-Assistance® in 98-100% of cases; and 3) a combination of diagnostic planes and/or VIS-Assistance® in 98-100% of cases. In all four abnormal cases, the FINE method demonstrated evidence of abnormal fetal cardiac anatomy.

CONCLUSIONS

The FINE method can be used to visualize nine standard fetal echocardiography views in normal hearts by applying 'intelligent navigation' technology to STIC volume datasets. This method can simplify examination of the fetal heart and reduce operator dependency. The observation of abnormal echocardiography views in the diagnostic planes and/or VIS-Assistance® should raise the index of suspicion for congenital heart disease.

The fetal cardiovascular response to increased placental vascular impedance to flow determined with 4-dimensional ultrasound using spatiotemporal image correlation and virtual organ computer-aided analysis

OBJECTIVE

We sought to determine if increased placental vascular impedance to flow is associated with changes in fetal cardiac function using spatiotemporal image correlation and virtual organ computer-aided analysis.

STUDY DESIGN

A cross-sectional study was performed in fetuses with umbilical artery pulsatility index >95th percentile (abnormal [ABN]). Ventricular volume (end-systole, end-diastole), stroke volume, cardiac output (CO), adjusted CO, and ejection fraction were compared to those of 184 normal fetuses.

RESULTS

A total of 34 fetuses were evaluated at a median gestational age of 28.3 (range, 20.6-36.9) weeks. Mean ventricular volumes were lower for ABN than normal cases (end-systole, end-diastole) with a proportionally greater decrease for left ventricular volume (vs right). Mean left and right stroke volume, CO, and adjusted CO were lower for ABN (vs normal) cases. Right ventricular volume, stroke volume, CO, and adjusted CO exceeded the left in ABN fetuses. Mean ejection fraction was greater for ABN than normal cases. Median left ejection fraction was greater (vs right) in ABN fetuses.

CONCLUSION

Increased placental vascular impedance to flow is associated with changes in fetal cardiac function.

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.