Current applications of fetal cardiac imaging technology

Abstract

Over the last few years, great progress has been made in imaging technology, which is changing the way prenatal visualization of the fetal heart is used for diagnosis and therapy. This paper reviews recent clinical research using these new techniques, namely dynamic three-dimensional (4D) echocardiography, myocardial Doppler imaging, B-flow ultrasonography, endoscopic ultrasound, and magnetic resonance imaging. Of them, 4D echocardiography is the most significant development and is discussed in greater detail. This includes real-time volumetric data acquisition using matrix-array transducer technology, motion artefact elimination using spatio-temporal image correlation, and various display options. The advantages and limitations of each are also addressed. These techniques can provide (1) sequential assessment of the entire heart using a full 4D dataset, (2) 4D delineation of trabeculation patterns on the ventricular walls, en-face dynamic shapes of ventricular septal defects and spatially complex malformations, (3) derivation of cardiac indices to myocardial contractility and strain rate by Doppler tissue imaging, and/or (4) the use of transoesophageal ultrasound to guide in-utero cardiac intervention. All of these techniques expand our ability to evaluate the morphology and function of the in-utero heart.