Myocardial motion imaging: a new application of power color flow and frequency-based color flow Doppler in fetal echocardiography.

Abstract

Myocardial motion imaging is a new way of looking at the fetal heart using power color flow and frequency-based color flow Doppler to demonstrate heart wall movement in color. This study set out to assess the value of myocardial motion imaging in fetal echocardiography in a routine clinical setting. In our hospital, all patients at high risk of carrying a fetus with a cardiac abnormality are offered detailed ultrasound scanning, including fetal echocardiography, at 20 weeks' gestation. A prospective study was carried out over a 2-month period and, in addition to conventional fetal echocardiography, myocardial motion imaging was also carried out on all patients, by means of both power color flow and frequency-based color flow Doppler ultrasound. Myocardial motion imaging demonstrated fetal heart wall movement in 26 of the 27 patients. Myocardial motion imaging using power color flow gave a global view of fetal heart wall movement, demonstrating both atrial and ventricular contraction simultaneously. Myocardial motion imaging using frequency-based color flow Doppler demonstrated atrial and ventricular contractions separately. In addition, as the direction of fetal heart wall motion can be color coded, atrial contractions, ventricular relaxation and ventricular contraction were demonstrated, providing a functional assessment of fetal heart wall movement. Two cases of cardiac abnormality were also studied, one case of hypoplastic left heart syndrome and one case of atrioventricular septal defect. In both cases functional information was obtained using myocardial motion imaging, and the technique also highlighted the anatomical defect. Myocardial motion imaging produces both a global view of fetal cardiac anatomy and a functional assessment of individual chamber contraction in the normal and abnormal heart. It may prove to be a useful adjunct to conventional color flow Doppler assessment of the fetal heart.