The current state and potential innovation of fetal cardiac MRI

Abstract

Fetal cardiac MRI is a rapidly evolving form of diagnostic testing with utility as a complementary imaging modality for the diagnosis of congenital heart disease and assessment of the fetal cardiovascular system. Previous technical limitations without cardiac gating for the fetal heart rate has been overcome with recent technology. There is potential utility of fetal electrocardiography for direct cardiac gating. In addition to anatomic assessment, innovative technology has allowed for assessment of blood flow, 3D datasets, and 4D flow, providing important insight into fetal cardiovascular physiology. Despite remaining technical barriers, with increased use of fCMR worldwide, it will become an important clinical tool to improve the prenatal care of fetuses with CHD.

Fetal MRI-Based Mediastinal Shift Angle (MSA) and Percentage Area of Left Ventricle (pALV) as Prognostic Parameters for Congenital Diaphragmatic Hernia

“…Long-time fetal cardiac MRI (fCMR) was technically limited due to the movement of the fetus, the small size of the fetal structures, and the lack of real-time fetal electrocardiography (ECG) to synchronize the data with the fetal cardiac cycle [ 17 ].…”

“…Surface ECG is one of the preferred gating techniques in fetal cardiac MRI. The ECG records the different phases of the fetal cardiac cycle and synchronizes the imaging of the MRI with the different phases of the cardiac cycle [ 17 ]. The gating system ensures that the images of the fetal heart are taken exactly when it is in a certain phase of the cardiac cycle to minimize motion artifacts and obtain high-resolution images.…”

“…In addition to ECG gating, there are other methods of gating: metric-optimized gating and Doppler ultrasound gating (DUS-gating) [ 17 , 18 ]. With metric-optimized gating, data are recorded at an exaggerated time and a post-processing technique is used to assign the correct heart rate after scanning.…”

“…MR-compatible DUS offers another option. The ultrasound device is based on Doppler waveforms of the heart rate trigger and is directly connected to the MR scanner [ 17 , 18 ]. However, this method is susceptible to movement.…”

Deep learning denoising reconstruction for improved image quality in fetal cardiac cine MRI

“…Cardiac MRI is the preferred modality for imaging congenital heart disease (CHD) in children and adults, providing ventricular volumetry, functional analysis, and hemodynamic assessment without ionizing radiation (1). Novel technical advancements, such as Doppler ultrasound (DUS) gating, now enable the successful application of dynamic cardiac cine MRI to the fetus in clinical routine (2)(3)(4)(5)(6). In contrast to other fetal cardiac gating methods, such as metric-optimized gating and self-gating strategies, DUS allows for direct gating without the need for time-consuming image post-processing, thus enabling the application of clinically used standard sequences to the fetal heart with the ability to immediately review images and adjust planes, if necessary (7).…”