Fetal Myocardial Wall Area: Constructing a Reference Range by Means of Spatiotemporal Image Correlation in the Rendering Mode

Abstract

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 cm² at 20 weeks 0 day to 2.75 ± 0.69 cm² at 33 weeks 6 days of gestation. The mean myocardial area of the fetal left ventricular (LV) wall ranged from 0.82 ± 0.20 cm² at 20 weeks 0 day to 2.49 ± 0.59 cm² 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.