Automated analysis of color tissue Doppler velocity recordings of the fetal myocardium using a new algorithm

Abstract

BackgroundTissue Doppler imaging (TDI) can be used to assess fetal cardiac function and it has been shown to detect changes associated with hypoxia in animal models. However, the analysis is cumbersome and time consuming. The main objective of this study was to evaluate the feasibility of a new algorithm developed for the automated analysis of color TDI velocity recordings of the fetal myocardium. Furthermore, we wanted to assess the effect of different sizes of region of interests (ROI) on the measurement of cardiac cycle time intervals and myocardial velocities at different gestations.MethodsThis study included analysis of 261 TDI velocity traces obtained from 17 fetal echocardiographic examinations performed longitudinally on five pregnant women. Cine-loops of fetal cardiac four chamber view were recorded with color overlay in TDI mode and stored for off-line analysis. ROIs of different sizes were placed at the level of the atrioventricular plane in the septum and in the right and left ventricular walls of the fetal heart. An automated algorithm was then used for the analysis of velocity traces.ResultsOut of the total 261 velocity traces, it was possible to analyze 203 (78 %) traces with the automated algorithm. It was possible to analyze 93 % (81/87) of traces recorded from the right ventricular wall, 82 % (71/87) from the left ventricular wall and 59 % (51/87) from the septum. There was a trend towards decreasing myocardial velocities with increasing ROI length. However, the cardiac cycle time intervals were similar irrespective of which ROI size was used.ConclusionsAn automated analysis of color TDI fetal myocardial velocity traces seems feasible, especially for measuring cardiac cycle time intervals, and has the potential for clinical application.

Measurement of cardiac function by cardiac time intervals, applicability in normal pregnancy and twin-to-twin transfusion syndrome

“…In adults, cTDI is used as prognostic tool in heart failure and differentiation between constrictive pericarditis and restrictive cardiomyopathy [10][11][12]. In fetal echocardiography, cTDI was first described for the assessment of myocardial velocities by Paladini et al [13], in pregnancies complicated by intrauterine growth restriction or gestational diabetes [14][15][16][17][18]. cTDI does not differentiate between active motion and passive motion; thus, fetal or maternal movements may cause artefacts.…”

Automated analysis of fetal cardiac function using color tissue Doppler imaging

“…It was possible to analyze all myocardial velocity traces with the automated algorithm, and all myocardial velocities and mechanical cardiac time intervals could be measured in 96% of traces. This is a significant improvement compared with our previous study, due to further refinement of our automated algorithm. There were significant correlations between myocardial velocities measured by automated and manual methods but correlations were weak or not significant for the mechanical cardiac time intervals.…”

“…), using EchoPAC version 201 (GE Vingmed Ultrasound AS, Horten, Norway). A region of interest measuring 6 × 4 mm (height × width), thought to be optimal for this gestational age based on previous research, was placed at the level of the atrioventricular (AV) plane, in the septal and the right (RV) and left ventricular (LV) walls of the fetal heart (Figure ). The smoothing filter in EchoPAC was set to three‐sample moving average.…”

“…To evaluate the clinical applicability of cTDI in larger groups of patients and facilitate its clinical implementation, a simpler and more automated procedure would be preferable. Our research group has demonstrated previously the feasibility of applying an automated algorithm in a small group of patients. However, the ability of this method to measure myocardial velocities and mechanical cardiac time intervals has not been evaluated in a larger cohort.…”

Automated analysis of fetal cardiac function using color tissue Doppler imaging in second half of normal pregnancy

“…However, the offline analysis of myocardial velocity traces generated using cTDI cine-loops is cumbersome and time-consuming, and there is a need to improve and simplify the analysis. Our group has demonstrated previously the feasibility of an automated algorithm for the analysis of cTDI myocardial velocity traces 16 and used this to evaluate fetal cardiac function in postdates pregnancies 17 . In the present study, we hypothesized that automated analysis could be used throughout the second half of pregnancy to measure parameters describing fetal cardiac function.…”