Fetal cardiac MRI: a single center experience over 14-years on the potential utility as an adjunct to fetal technically inadequate echocardiography

Abstract

Unlike ultrasound (US) imaging, foetal magnetic resonance imaging (MRI) is not significantly limited by maternal obesity, oligohydramnios, uterine myoma, twins, and foetal lie, which impair US visualization of the foetus. The present study aimed to introduce our foetal cardiac MRI scanning technology and over 14-years of experience on the potential utility of foetal cardiac MRI examination as an adjunct to foetal technically inadequate echocardiography (Echo). This retrospective review included 1,573 pregnant women [1,619 foetuses (46 twins)] referred for a foetal cardiac MRI because of technically limited Echo. Foetal cardiac MRI was performed using two 1.5 T units. Among the 1,619 foetuses referred for cardiac MRI, 1,379 (85.2%) cases were followed up using postnatal imaging and/ or surgery, 240 (14.8%), including three twins, had no follow-up confirmation because of pregnancy termination without autopsy or loss to follow-up. The results of the present study indicated that foetal cardiac MRI examinations can be a useful adjunct to foetal echocardiography when the technical limitations of echocardiography make it inadequate for diagnosis. The foetal cardiovascular system is the most frequently affected among congenital pathologies. Congenital heart disease (CHD) is the most common congenital anomaly and is the major cause of infant mortality 1. Prenatal diagnosis of certain types of CHD, such as transposition of the great arteries (TGA), pulmonary atresia with intact ventricle septum (PA/IVS), hypoplastic left heart syndrome (HLHS), obstructive total anomalous pulmonary veins connection (TAPVC), and other severe CHDs has been associated with improved outcomes and decreased perioperative mortality 2. Foetal cardiac examination has become a routine part of screening foetal ultrasound (US), and suspected cardiac anomalies will require more comprehensive evaluation using foetal echocardiography (Echo). Foetal magnetic resonance imaging (MRI) examinations have become useful adjuncts to ultrasound (US) exams when US diagnosis is doubtful. To date, there has been no clinical or experimental evidence that MRI has any adverse effects on the human foetus in the second or third trimester 3,4. Unlike US imaging, foetal MRI is not significantly limited by maternal obesity, oligohydramnios, uterine myoma, twins, and foetal lie, all of which impair US visualization of the foetus 5-7. The visualization of the foetal heart using MRI is complicated because of the small heart size, high heart rate, and foetal motion 4,8. Several studies revealed new techniques (such as compressed sensing, motion correction, and foetal cardiac gating) to reveal further details in MRI studies of the foetal heart and great vessels 10-13. Foetal cardiac MRI has the potential to complement echocardiography to detect cardiovascular anomalies 14,15. However, currently, there has been no report on the potential utility of foetal cardiovascular MRI as an adjunct to foetal echocardiography when echocardiography is technically limited, either from a single c...

Cerebral Blood Flow Monitoring in High-Risk Fetal and Neonatal Populations

“…When combined with phase contrast MRI, which quantifies velocity of moving fluids, accurate measurements of fetal blood flow are possible. One major obstacle to this imaging is the necessity of timing image acquisition with the cardiac cycle (47)(48)(49)(50)(51). Cardiac gating is used to time data acquisition with specific phases of the cardiac cycle, and MRI-compatible fetal ECG devices are now available (48,(51)(52)(53)(54)(55).…”

Utility of Fetal Cardiovascular Magnetic Resonance for Prenatal Diagnosis of Complex Congenital Heart Defects

“…Until recently, fetal cardiovascular magnetic resonance (CMR) imaging has been dependent on either real-time acquisition, which typically is of low spatial resolution, static acquisition, or in-house postprocessing techniques due to lack of methods for direct cardiac gating. 11 , 12 , 13 , 14 , 15 , 16 With the development of an MR-compatible Doppler ultrasound (DUS) device, 17 it is possible to acquire high-resolution fetal CMR images without postprocessing, making fetal CMR potentially more clinically applicable. 18 , 19 , 20 , 21 Since echocardiography requires less time and resources compared with CMR, fetal CMR would likely serve as a complement to fetal echocardiography in challenging cases.…”

“… 22 However, these studies focused on extracardiac vascular anomalies 23 or relied on real-time acquisition with limited spatial resolution for cardiac cine imaging. 16 Standard and widely available fetal cardiac-gated cine sequences may increase visualization of intracardiac anatomy and cardiac function and increase image quality of the fetal heart and large vessels. However, it is unknown to what extent this may affect clinical care.…”

Fetal Cardiovascular MRI – A Systemic Review of the Literature: Challenges, New Technical Developments, and Perspectives

“…Non-Gated Fetal CMR Fetal echocardiography has proven its ability to detect congenital cardiovascular pathologies and is established as the diagnostic reference standard, yet with certain technical limitations, strong dependency on the examiners' expertise, and therefore highly variable detection rates between 34 % and 86 % [5,7]. A singlecenter experience performing non-gated CMR in 1619 fetuses where echocardiography was technically inadequate concluded that fetal CMR can be a useful adjunct when technical limitations make echocardiography inappropriate for diagnosis [7]. The main limitation of prenatal echocardiography was maternal obesity in 1082 fetuses, followed by an unfavorable fetal position in utero (404 fetuses), oligohydramnios (70 fetuses), maternal abdominal wall edema (42 fetuses), and uterine myomas (21 fetuses).…”