Quantitative evaluation of fetal right and left ventricular fractional area change using speckle-tracking technology.

OBJECTIVES: To measure, using speckle-tracking technology, the fractional area change (FAC) of the right and left ventricles in normal fetal hearts between 20 and 40 weeks of gestation. METHODS: The four-chamber view of the fetal heart was obtained in 200 normal fetuses between 20 and 40 weeks of gestation. FAC was computed from the ventricular areas (((end-diastolic area - end-systolic area)/end-diastolic area) × 100) for the right and left ventricles, and regressed against seven independent biometric and age variables. FAC was correlated with longitudinal fractional shortening (LFS) (((end-diastolic longitudinal length - end-systolic longitudinal length)/end-diastolic longitudinal length) × 100) obtained from the mid-ventricular basal-apical lengths of the right and left ventricular chambers and with transverse fractional shortening (TFS) (((end-diastolic transverse length - end-systolic transverse length)/end-diastolic transverse length) × 100) from three transverse positions (base, mid, apical) located within each ventricular chamber. To evaluate potential clinical utility, FAC, LFS and TFS results were examined in nine fetuses with a congenital heart defect (CHD). RESULTS: Regression analysis demonstrated significant associations between FAC and the independent biometric and age variables (R2  = 0.13-0.15). FAC was significantly correlated with LFS (R2  = 0.18-0.28) and TFS (R2  = 0.13-0.33). Examination of the fetuses with CHD revealed that six of the nine had abnormal FAC Z-score values for the index pathological ventricle. When abnormal LFS and TFS values were compared to the FAC in these fetuses, the FAC was either abnormally low or normal. CONCLUSIONS: This study reports results from measuring the FAC of the right and left ventricles, and demonstrates a correlation with LFS and TFS. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

24-segment sphericity index: a new technique to evaluate fetal cardiac diastolic shape.

OBJECTIVE: Because of parallel circulation in the fetus and the differential effect that various disease states may have on the shape of the right and left ventricles, this study was conducted to evaluate the sphericity index (SI) of 24 transverse segments distributed from the base to the apex of each of the ventricular chambers. METHODS: Two hundred control fetuses were examined between 20 and 40 weeks of gestation. The displacement of the ventricular endocardium during the cardiac cycle was computed using offline speckle-tracking software. From the ASCII output of the analysis, we analyzed 24 end-diastolic transverse segments, distributed from the base to the apex of each ventricle, as well as the end-diastolic mid-basal-apical length. The SI was computed for each of the 24 segments by dividing the mid-basal-apical length by the transverse length for each segment. Regression analysis was performed against biometric measurements and gestational age according to last menstrual period and ultrasound. Eight fetuses, in which the four-chamber view appeared subjectively to demonstrate chamber disproportion, were evaluated as examples to demonstrate the utility of this technology. RESULTS: The SI for each segment was independent of gestational age and fetal biometric measurements. The SI of the right ventricle was significantly (P < 0.001) lower than that of the left ventricle for segments 1-18, suggesting that the right ventricle was more globular in shape than was the left ventricle at the base, mid and a portion of the apical segments of the chamber. Fetuses with various cardiac structural abnormalities and abnormal fetal growth had abnormal SI values that reflected either a more globular or a more flattened ventricular chamber. CONCLUSION: Determination of SI for each of 24 segments of the fetal right and left ventricles provides a comprehensive method to examine the shape of the ventricular chambers. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Delineation of site, relative size and dynamic geometry of atrial septal defects by real-time three-dimensional echocardiography.

OBJECTIVES: This study attempted to determine the site, relative size and dynamic geometry of atrial septal defects using dynamic three-dimensional echocardiography. BACKGROUND: Recent studies have demonstrated the feasibility of dynamic three-dimensional echocardiography. Images are acquired from computerized reconstruction of sequential, tomographic ultrasound "slices" of the heart. Ultrasound images can be obtained by linear progression of a transducer within a transesophageal imaging probe. In small infants and children the large transducer size has not allowed transesophageal placement, and the probe has been placed on the thorax or in the subcostal position. Other scanning devices, housed in plastic containers, acquire images in a rotational format and can also be placed in a transthoracic or subcostal position. METHODS: Specially designed transesophageal probes and a dedicated computer unit were used for two-dimensional image retrieval and reconstruction of three-dimensional images. Sixteen patients with atrial septal defects were studied (median age 18 months, range 1 day to 18 years). In one patient, images were obtained by transesophageal probe placement; in the other 15 patients, the probe was placed in the transthoracic or subcostal position. RESULTS: A dynamic three-dimensional echocardiogram of the atrial septal defect could be obtained in 13 of the 16 patients. The distinguishing features of the atrial septal defects and their spatial orientation could be visualized in unique three-dimensional views. CONCLUSIONS: Dynamic three-dimensional imaging could be applied to the specific evaluation of atrial septal defects. Unique views of the heart allowed for spatial comprehension of the defects, rendering potentially important clinical information.

Quantitative assessment of normal and stenotic aortic valve using transesophageal three-dimensional echocardiography.

The present study demonstrates the feasibility of transesophageal three-dimensional reconstruction of normal, sclerotic, and stenotic aortic valves using a computed tomographic ultrasound system. The study also shows the potential clinical usefulness of this technique in delineating aortic valve morphology (extent and severity of valve thickening and calcification and size and number of cusps) and assessing aortic orifice areas by direct planimetry of the three-dimensional images.