Feasibility of automated fetal fractional shortening measurement with two-dimensional tracking and construction of a reference range for normal fetuses.

PURPOSE: To assess the feasibility of an automated fractional shortening (Auto FS) measurement method using two-dimensional tracking and to construct a reference range for normal fetuses. METHODS: This study was conducted from May 2017 to March 2018. First, cardiac motion in the four-chamber view was recorded in the B-mode. Subsequently, the region of interest was set on the edge of the ventricular septum or ventricular muscle at a point one-third away from the atrioventricular valve toward the cardiac apex. Tracking was automatically performed. Values measured between the ventricular septum and right ventricle were defined as R-Auto FS, whereas those measured between the ventricular septum and left ventricle were defined as L-Auto FS. Those on each ventricular muscle were defined as Combined-Auto FS. RESULTS: Data were obtained from 131 singleton fetuses. R-Auto FS significantly decreased with an increase in the number of gestational weeks, and L-Auto FS and Combined-Auto FS showed the same tendency (Spearman's correlation analysis: p = - .528, p = - .351, and p = - .636, respectively). CONCLUSION: We succeeded in defining a reference Auto FS value for normal singleton pregnancies. Auto FS was negatively correlated with gestational age. This novel technique can assess fetal heart contractility.

Reproducibility of automated fetal heart rate measurement using a novel technique with two-dimensional tracking.

PURPOSE: To assess the accuracy of automated fetal heart rate measurement using two-dimensional tracking (AutoFHR) by comparison with the conventional free-angle M-mode (M-mode) and pulsed-waved Doppler (PWD) methods. METHODS: A multicenter prospective comparative study was conducted. AutoFHR is a novel technique for the automatic calculation of fetal heart rate using a two-dimensional speckle-tracking method. The fetal heart rate (FHR) obtained by AutoFHR was compared with that obtained by the conventional M-mode and PWD. Statistical analysis was performed on the correlation between the FHR measured by AutoFHR and that determined by M-mode and PWD. RESULTS: Data from 326 singleton pregnancies were analyzed, and all the data and the data from 178 cases were compared with M-mode and PWD, respectively. The intraobserver ICC was 0.96 (95% CI: 0.93-0.98), whereas the interobserver ICC was 0.97 (95% CI: 0.95-0.99). Systematic bias was not observed between M-mode and PWD, based on the Bland-Altman plots. Analyses of the relationships among the FHRs yielded by each method revealed that AutoFHR was strongly associated with M-mode (rs = 0.99, p < 0.001) and PWD (rs = 0.86, p < 0.001). CONCLUSION: Evaluation of FHR by AutoFHR was proved to be equivalent to evaluation by the conventional M-mode and PWD. AutoFHR can be employed with only B-mode data, making FHR measurement easier and safer.