A 24-segment fractional shortening of the fetal heart using FetalHQ

Evaluation of Fetal Heart Using Fetal Heart Quantification (fetalHQ) Technique in an Indian Cohort

OBJECTIVE

To evaluate the intra- and interobserver reproducibility of parameters used to determine cardiac morphometry and deformation using FetalHQ in Indian population.

METHODOLOGY

Two operators blinded to each other performed FetalHQ analysis independently on 35 normal fetuses of gestational age between 18 + 0 and 37 + 0 weeks and days. Intra- and interobserver correlation coefficient and limits of agreement were ascertained for parameters obtained from HQ analysis.

RESULTS

Excellent reproducibility (ICC > 0.9) was observed for global morphometric parameters. Ejection fraction, stroke volume, stroke volume/kg demonstrated excellent reliability (ICC > 0.9), cardiac output, fractional area change showed a lower correlation (ICC < 0.8), and right and left ventricular global strain showed no correlation. Twenty-four segment sphericity index of left ventricle (LV) and right ventricle (RV) showed low to moderate correlation (LV-ICC 0.48-0.79; RV-ICC 0.43-0.82). Fractional shortening (FS) showed poor intraobserver reliability in RV.

CONCLUSION

FetalHQ provides reliable estimates of the global cardiac morphometry but not for global cardiac strain. Regional transverse contractility represented by FS has poor correlation in right ventricle, especially in the apical region, possibly due to moderator band. Nevertheless, it is a promising tool which requires technical advancements and validation to improve its accuracy and reliability.

Reproducibility Analysis of Two Speckle Tracking Software for the Antenatal Semiautomated Assessment of the Fetal Cardiac Function

INTRODUCTION

Speckle tracking echocardiography is a non-Doppler modality allowing the semiautomated evaluation of the fetal cardiac function by tracking the speckles of the endocardial borders. Little evidence is available on the evaluation and comparison of different software for the functional assessment of the fetal heart by means of speckle tracking echocardiography. The aim of this study was to evaluate the reproducibility and agreement of two different proprietary speckle tracking software for the prenatal semiautomated assessment of the fetal cardiac function.

METHODS

The prospective study including non-anomalous fetuses was referred for different indications at two tertiary academic units in Italy (University of Parma) and Spain (University of Barcelona). Two-dimensional clips of the four-chamber view of the fetal heart were acquired by two dedicated operators using high-end ultrasound machines with a frame rate higher than 60 Hz. The stored clips were pseudo-anonymized and shared between the collaborating units. Functional echocardiographic analyses were independently performed using the two proprietary software (TomTec GmbH and FetalHQ®) by the same operators. Inter-software reproducibility of the endocardial global longitudinal strain (EndoGLS) and fractional area change (FAC) of the left (LV) and the right ventricles (RV) and ejection fraction (EF) of the LV were evaluated by the intraclass correlation coefficient (ICC).

RESULTS

Forty-eight fetuses were included at a median of 31+2 (21+6-40+3) gestational weeks. Moderate reproducibility was found for the functional parameters of the LV: EndoGLS (Pearson's correlation 0.456, p < 0.01; ICC 0.446, 95% CI: 0.189-0.647, p < 0.01); EF (Pearson's correlation 0.435, p < 0.01; ICC 0.419, 95% CI: 0.156-0.627, p < 0.01); FAC (Person's correlation 0.484, p < 0.01; ICC 0.475, 95% CI: 0.223-0.667, p < 0.01). On the contrary, RV functional parameters showed poor reproducibility between the two software: EndoGLS (Pearson's correlation 0.383, p = 0.01; ICC 0.377, 95% CI: 0.107-0.596, p < 0.01) and FAC (ICC 0.284, 95% CI: 0.003-0.524, p = 0.02).

CONCLUSION

Our results demonstrate a moderate reproducibility of the speckle tracking analysis of the LV using TomTec GmbH and FetalHQ®, with poor reproducibility for RV analysis.

Feasibility of 4D-Spatio Temporal Image Correlation (STIC) in the Comprehensive Assessment of the Fetal Heart Using FetalHQ®

Fetal Heart Quantification (FetalHQ®) is a novel speckle tracking software that permits the study of global and regional ventricular shape and function from a 2D four-chamber-view loop. The 4D-Spatio Temporal Image Correlation (STIC) modality enables the offline analysis of optimized and perfectly aligned cardiac planes. We aimed to evaluate the feasibility and reproducibility of 4D-STIC speckle tracking echocardiography (STE) using FetalHQ® and to compare it to 2D STE. We conducted a prospective study including 31 low-risk singleton pregnancies between 20 and 40 weeks of gestation. Four-chamber view volumes and 2D clips were acquired with an apex pointing at 45° and with a frame rate higher than 60 Hz. Morphometric and functional echocardiography was performed by FetalHQ®. Intra- and interobserver reproducibility were evaluated by the intraclass correlation coefficient (ICC). Our results showed excellent reproducibility (ICC > 0.900) for morphometric evaluation (biventricular area, longitudinal and transverse diameters). Reproducibility was also good (ICC > 0.800) for functional evaluation (biventricular strain, Fractional Area Change, left ventricle volumes, ejection fraction and cardiac output). On the contrary, the study of the sphericity index and shortening fraction of the different ventricular segments showed lower reproducibility (ICC < 0.800). To conclude, 4D-STIC is feasible, reproducible and comparable to 2D echocardiography for the assessment of cardiac morphometry and function.

Novel Speckle Tracking Analysis Showed Excellent Reproducibility for Size and Shape of the Fetal Heart and Good Reproducibility for Strain and Fractional Shortening

INTRODUCTION

This study aimed to evaluate reproducibility and agreement of fetal cardiac shape and deformation using FetalHQ.

METHODS

Fifty normal fetuses at 20-38 weeks of gestation were evaluated. Two operators independently selected an optimal cardiac cycle using FetalHQ®™software for speckle tracking analysis. Intra- and interobserver correlation coefficient and limits of agreement for cardiac shape and deformation were estimated.

RESULTS

Global cardiac markers: high correlation (r = 0.98) and agreement (mean difference, standard deviation [MD, SD] 5.07, 75.8) for ventricular area; moderate correlation (r = 0.78) and agreement (MD, SD: 0.016, 0.08) for global sphericity index (SI) and for left ventricle (LV) global strain (r = 0.65; MD, SD: -4.48, 11.9); and low but still significant correlation (r = 0.58) and agreement (MD, SD: -3.77, 12.27) for right ventricle (RV) global strain. For individual ventricular parameters: high correlation for LV ([median r; range] 0.98; 0.93-0.99) and RV (r = 0.98; 0.97-1.0) SI, and for LV (r = 0.92: 0.56-0.99) and RV (r = 0.96; 0.67-0.99) end diastolic diameters; moderate correlation for LV fractional shortening (r = 0.53; 0.87-0.98); and no significant correlation for RV fractional shortening (r = 0.36; 0.32-0.97). Inter- and intraobserver correlation and agreement were similar for all evaluated parameters.

CONCLUSION

Speckle tracking analysis of the fetal heart provides reliable estimations of global and LV shape and deformation. Low correlation in the RV can be related to anatomical structures such as the moderator band.