Fetal Cardiac Magnetic Resonance Research Articles

Initial experience - clinical application and scoring system of real-time fetal cardiac magnetic resonance at 0.55T

Initial experience - clinical application and scoring system of real-time fetal cardiac magnetic resonance at 0.55T

Multimodal Approach (MRI and Ultrasonography) to the Diagnosis of Fetal Congenital Heart Diseases

Introduction: As the rate of congenital heart diseases (CHD) remains high, medical imaging specialists face a task of early diagnosis of CHD with minimal cost and burden to pregnant women and fetuses and need to verify the prenatal diagnosis in order to develop a strategy for managing pregnant women carrying a fetus with CHD.Objective: To optimize diagnostic measures in fetuses with CHD by comparing fetal echocardiography and cardiac magnetic resonance imaging (MRI).Materials and methods: We retrospectively evaluated findings from 35 fetal standard ultrasonography reports, 29 echocardiography reports, and 35 fetal autopsy reports (termination for medical reasons). We assessed 18 cases of CHD diagnosed by ultrasonography findings on the second screening; in 34% of the cases patients also underwent MRI at that time and a repeated procedure 30 weeks later.Results: When standard ultrasonography and an extended protocol with echocardiography were used together, diagnostic errors were 14.3%. In 85.7% of the fetuses, the findings of different imaging techniques fully coincided with the autopsy findings.Conclusions: In this cohort of pregnant women, the second screening should include more examinations to verify the diagnosis of CHD. Based on the first screening findings (increased nuchal translucency thickness and ductus venosus pulsatility index) patients should be referred to an expert for the second screening. If necessary, to verify the diagnosis of CHD ultrasonography and MRI can be combined during the third screening (34-36 weeks) in order to plan postnatal management of the newborn. The proposed algorithm for fetal CHD diagnosis enables to minimize the likelihood of error and maintain continuity of care between obstetricians-gynecologists, ultrasonographers, radiologists, neonatologists, and cardiologists.

Role of Fetal Cardiac ECHO and Fetal Cardiac MRI in Prediction of Post Natal Hemodynamic Maladaptation in Fetuses of Diabetic Mothers

Background: Maternal diabetes mellitus (DM) is defined as a degree of glucose intolerance with recognition during pregnancy (pregestational or gestational, type 1 or type 2), and it is estimated to be 15% in pregnant females in 2019. The current study aimed to study the role of fetal echocardiography and fetal cardiac magnetic resonance imaging (MRI) in anticipation and diagnosis of hemodynamic maladaptation changes in fetuses of diabetic mothers as predictors for (closure of Patent ductus arteriosus (PDA), persistent pulmonary hypertension and diastolic dysfunction) which were confirmed with post-natal echocardiographic and clinical assessment. Methods: This study was an observational follow-up study that included 80 pregnant diabetic females who were following in the specialized clinics of Ain Shams University Hospitals during the period starting from August 2020 till December 2022. Results: Diabetes affected left ventricle (LV) diastolic function and global cardiac function but did not affect LV systolic function (p-value=0.000). Interventricular septum (IVS) thickness had a significant positive correlation with LV- Myocardial performance index (MPI) and indices of DM such as HbA1c. Diastolic dysfunction was the most affected cardiac parameter in infants of diabetic mothers (p-value=0.002). The hemoglobin A1c (HbA1c) was the most significant predictor for IVS thickness in diabetic mothers' fetuses, especially with a long duration of DM (p-value=0.012). Conclusion: Fetal echocardiography in diabetic mothers is essential and the gold standard modality not only for diagnosing structural abnormalities but also for evaluating the cardiac function of the fetuses. Fetal cardiac MRI could be considered a complementary imaging modality that uses no ionizing radiation, good tissue contrast, and a larger field of view.

Double aortic arch: a comparison of fetal cardiovascular magnetic resonance, postnatal computed tomography and surgical findings

In double aortic arch (DAA), one of the arches can demonstrate atretic portions postnatally, leading to diagnostic uncertainty due to overlap with isolated right aortic arch (RAA) variants. The main objective of this study is to demonstrate the morphological evolution of different DAA phenotypes from prenatal to postnatal life using three-dimensional (3D) fetal cardiac magnetic resonance (CMR) imaging and postnatal computed tomography (CT)/CMR imaging. Three-dimensional fetal CMR was undertaken in fetuses with suspected DAA over a 6-year period (January 2016-January 2022). All cases with surgical confirmation of DAA were retrospectively studied and morphology on fetal CMR was compared to postnatal CT/CMR and surgical findings. Thirty-four fetuses with surgically confirmed DAA underwent fetal CMR. The RAA was dominant in 32/34 (94%). Postnatal CT/CMR was undertaken at a median age of 3.3months (interquartile range 2.0-3.9) demonstrating DAA with patency of both arches in 10/34 (29%), with 7 showing signs of coarctation of the left aortic arch (LAA). The LAA isthmus was not present on CT/CMR in 22/34 (65%), and the transverse arch between left carotid and left subclavian artery was not present in 2 cases. Fetal CMR provides novel insights into perinatal evolution of DAA. The smaller LAA can develop coarctation or atresia related to postnatal constriction of the arterial duct, making diagnosis of DAA challenging with contrast-enhanced CT/CMR. This highlights the potentially important role for prenatal 3D vascular imaging and might improve the interpretation of postnatal imaging.

Fetal cardiac magnetic resonance imaging of the descending aorta in suspected left-sided cardiac obstructions.

Severe left-sided cardiac obstructions are associated with high morbidity and mortality if not detected in time. The correct prenatal diagnosis of coarctation of the aorta (CoA) is difficult. Fetal cardiac magnetic resonance imaging (CMR) may improve the prenatal diagnosis of complex congenital heart defects. Flow measurements in the ascending aorta could aid in predicting postnatal CoA, but its accurate visualization is challenging. To compare the flow in the descending aorta (DAo) and umbilical vein (UV) in fetuses with suspected left-sided cardiac obstructions with and without the need for postnatal intervention and healthy controls by fetal phase-contrast CMR flow. A second objective was to determine if adding fetal CMR to echocardiography (echo) improves the fetal CoA diagnosis. Prospective fetal CMR phase-contrast flow in the DAo and UV and echo studies were conducted between 2017 and 2022. A total of 46 fetuses with suspected left-sided cardiac obstructions [11 hypoplastic left heart syndrome (HLHS), five critical aortic stenosis (cAS), and 30 CoA] and five controls were included. Neonatal interventions for left-sided cardiac obstructions (n = 23) or comfort care (n = 1 with HLHS) were pursued in all 16 fetuses with suspected HLHS or cAS and in eight (27%) fetuses with true CoA. DAo or UV flow was not different in fetuses with and without need of intervention. However, DAo and UV flows were lower in fetuses with either retrograde isthmic systolic flow [DAo flow 253 (72) vs. 261 (97) ml/kg/min, p = 0.035; UV flow 113 (75) vs. 161 (81) ml/kg/min, p = 0.04] or with suspected CoA and restrictive atrial septum [DAo flow 200 (71) vs. 268 (94) ml/kg/min, p = 0.04; UV flow 89 vs. 159 (76) ml/kg/min, p = 0.04] as well as in those without these changes. Adding fetal CMR to fetal echo predictors for postnatal CoA did not improve the diagnosis of CoA. Fetal CMR-derived DAo and UV flow measurements do not improve the prenatal diagnosis of left-sided cardiac obstructions, but they could be important in identifying fetuses with a more severe decrease in blood flow across the left side of the heart. The physiological explanation may be a markedly decreased left ventricular cardiac output with subsequent retrograde systolic isthmic flow and decreased total DAo flow.

Utility of Fetal Cardiac Resonance Imaging in Prenatal Clinical Practice: Current State of the Art

The field of prenatal cardiac imaging has revolutionized the way we understand and manage congenital heart diseases (CHD) in the developing fetus. In the prenatal period, cardiac imaging plays a pivotal role in the diagnostic pathway, from screening to classification and follow-up of CHD. The ability to visualize the fetal heart in utero allows healthcare professionals to detect abnormalities early, thus enabling timely interventions and informed decision-making processes for both the mother and the medical team. Early CHD detection improves preparation for delivery, postnatal care, and postnatal outcomes. Advancements in medical technology and imaging techniques have provided clinicians with insights into the fascinating workings of the fetal heart. Several imaging modalities have proven to be helpful in this field, with echocardiography undoubtedly representing the primary modality for evaluating the fetus. By providing detailed anatomical and functional information, fetal cardiac magnetic resonance (CMR) imaging contributes to better prenatal counseling and enhances the coordination of care between obstetricians, maternal–fetal medicine specialists, and pediatric cardiologists. Shortcomings of fetal CMR are due to technical concerns related to the intrauterine position of the fetus and subsequent challenges to following a standard scan protocol. The aim of this paper was to revise the current state-of-the-art in the field of fetal CMR and its clinical applications and to delve into methods, challenges, and future directions of fetal CMR in prenatal imaging.

Utility of fetal cardiac magnetic resonance imaging in assessing the cardiac axis in fetuses with congenital heart disease.

Fetal dedicated echocardiography is the standard to measure the fetal cardiac axis. However, fetal screening ultrasound (US) or fetal dedicated echocardiography may be technically limited. The purpose of this study was to explore the accuracy of fetal cardiac magnetic resonance imaging (MRI) to measure the cardiac axis in fetuses with congenital heart disease as an adjunct to fetal dedicated echocardiography and to assess the predictive value of fetal cardiac MRI measurements in distinguishing healthy fetuses from fetuses with congenital heart disease. This is a retrospective study of fetuses referred to our hospital for a fetal cardiac MRI from November 2019 to December 2021. Cardiac axes were measured in the 4-chamber view of the fetal heart using fetal cardiac MRI and dedicated echocardiography, or only using fetal cardiac MRI when screening US was technically limited. The fetuses were divided into a congenital heart disease group and a healthy control group. We used Bland-Altman analysis and the intraclass correlation coefficient (ICC) to assess the agreement of cardiac axis measurements in fetuses with congenital heart disease obtained by cardiac MRI and by fetal dedicated echocardiography. Receiver operating characteristic (ROC) curve analysis of the fetal cardiac axes in the congenital heart disease and healthy fetus groups assessed the predictive value of the cardiac axis measurements. This retrospective study included 431 women (162 carrying fetuses with congenital heart disease, 269 carrying healthy fetuses). Cardiac axes were measured in the 162 fetuses with congenital heart disease using fetal cardiac MRI and dedicated echocardiography. Cardiac axes were measured in the 269 healthy control fetuses using fetal cardiac MRI when fetal screening US was technically limited. The interobserver analysis and intraobserver analysis showed that the cardiac axis measured by fetal cardiac MRI and fetal dedicated echocardiography was repeatable (ICC>0.90). In 162 fetuses with congenital heart disease, Bland-Altman analysis showed a strong agreement between cardiac MRI and fetal dedicated echocardiography measurements for the cardiac axis. The ICC for the cardiac axis values between cardiac MRI and fetal dedicated echocardiography measurements was 0.99. In fetuses with congenital heart disease, 64.2% (104/162) had an abnormal cardiac axis. For the fetal cardiac axis in both the 162 fetuses with congenital heart disease and the 269 healthy fetuses, the area under the ROC curve reached 0.85 (95% confidence interval: 0.80-0.89; P<0.0001). The cardiac axis can be accurately measured using fetal cardiac MRI when fetal dedicated echocardiography/fetal screening US is technically limited. The cardiac axis measurements by fetal cardiac MRI are consistent with known cardiac axis measurements by fetal dedicated echocardiography. The frequency of abnormal cardiac axis depends on the type of congenital heart disease.

Four-dimensional fetal cardiac imaging in a cohort of fetuses with suspected congenital heart disease.

Fetal cardiac magnetic resonance imaging (MRI) requires high spatial and temporal resolution and robustness to random fetal motion to capture the dynamics of the beating fetal heart. Slice-to-volume reconstruction techniques can produce high-resolution isotropic images while compensating for random fetal motion. The objective of this study was to evaluate image quality for slice-to-volume reconstruction of four-dimensional balanced steady-state free precession (bSSFP) imaging of the fetal heart. A cohort of 13 women carrying fetuses with congenital heart disease were imaged with real-time bSSFP sequences. Real-time bSSFP sequences were post-processed using a slice-to-volume reconstruction algorithm to produce retrospectively gated 4-D sequences with isotropic spatial resolution. Two radiologists evaluated slice-to-volume reconstruction image quality on a scale from 0 to 4 using 11 categories based on a segmental approach to defining cardiac anatomy and pathology. A score of 0 corresponded to cardiac structures not visualized at all and four corresponded to high quality and distinct appearance of structures. In 11 out of 13 cases, the average radiologist score of image quality across all categories was 3.0 or greater. In the remaining two cases, slice-to-volume reconstruction was not possible due to insufficient image quality in the acquisition. Slice-to-volume reconstruction has the potential to produce isotropic images with high spatial and temporal resolution that can display the anatomy of the fetal heart in arbitrary imaging planes retrospectively. More rapid, motion-robust acquisitions may be necessary to successfully reconstruct the fetal heart in all patients.

Super-Resolution Cine Image Enhancement for Fetal Cardiac Magnetic Resonance Imaging.

Fetal cardiac magnetic resonance imaging (MRI) improves the diagnosis of congenital heart defects, but is sensitive to fetal motion due to long image acquisition time. This may be overcome with faster image acquisition with low resolution, followed by image enhancement to provide clinically useful images. To combine phase-encoding undersampling with super-resolution neural networks to achieve high-resolution fetal cine cardiac MR images with short acquisition time. Prospective. Twenty-eight fetuses (gestational week 36 [interquartile range 33-38 weeks]). 1.5 T, balanced steady-state free precession (bSSFP) cine sequence. Images were acquired using fully sampled Doppler ultrasound-gated clinical bSSFP cine as reference, with equivalent cine sequences with decreased phase-encoding resolution (25%, 33%, and 50% of clinical standard). Two super-resolution methods based on convolutional neural networks were proposed and evaluated (phasrGAN and phasrresnet). Data were partitioned into training (36 cine slices), validation (3 cine slices), and test sets (67 cine slices) without overlap. Conventional reconstruction methods using bicubic interpolation and k-space zeropadding were used for comparison. Three blinded observers scored image quality between 1 and 10. Image scores are reported as median [interquartile range] and were compared using Mann-Whitney's nonparametric test with P < 0.05 showing statistically significant differences. Both proposed methods showed no significant difference in image quality compared to clinical images (8 [7-8.5]) down to 33% (phasrGAN 8 [6.5-8]; phasrresnet 8 [7-8], all P ≥ 0.19) phase-encoding resolution, i.e., up to three times faster image acquisition, whereas bicubic interpolation and k-space zeropadding showed significantly lower quality for 33% phase-encoding resolution (both 7 [6-8]). Super-resolution enhancement can be used for fetal cine cardiac MRI to reduce image acquisition time while maintaining image quality. This may lead to an improved success rate for fetal cine MR imaging, as the impact of fetal motion is lessened by shortened acquisitions. 1 TECHNICAL EFFICACY: Stage 2.

Analysis of 3-Dimensional Arch Anatomy, Vascular Flow, and Postnatal Outcome in Cases of Suspected Coarctation of the Aorta Using Fetal Cardiac Magnetic Resonance Imaging.

Identifying fetuses at risk of severe neonatal coarctation of the aorta (CoA) can be lifesaving but is notoriously challenging in clinical practice with a high rate of false positives. Novel fetal 3-dimensional and phase-contrast magnetic resonance imaging (MRI) offers an unprecedented means of assessing the human fetal cardiovascular system before birth. We performed detailed MRI assessment of fetal vascular morphology and flows in a cohort of fetuses with suspected CoA, correlated with the need for postnatal intervention. Women carrying a fetus with suspected CoA on echocardiography were referred for MRI assessment between 26 and 36 weeks of gestation, including high-resolution motion-corrected 3-dimensional volumes of the fetal heart and phase-contrast flow sequences gated with metric optimized gating. The relationship between aortic geometry and vascular flows was then analyzed and compared with postnatal outcome. Seventy-two patients (51 with suspected fetal CoA and 21 healthy controls) underwent fetal MRI with motion-corrected 3-dimensional vascular reconstructions. Vascular flow measurements from phase-contrast sequences were available in 53 patients. In the CoA group, 25 of 51 (49%) required surgical repair of coarctation after birth; the remaining 26 of 51 (51%) were discharged without neonatal intervention. Reduced blood flow in the fetal ascending aorta and at the aortic isthmus was associated with increasing angulation (P=0.005) and proximal displacement (P=0.006) of the isthmus and was seen in both true positive and false positive cases. A multivariate logistic regression model including aortic flow and isthmal displacement explained 78% of the variation in outcome and correctly predicted the need for intervention in 93% of cases. Reduced blood flow though the left heart is associated with important configurational changes at the aortic isthmus in fetal life, predisposing to CoA when the arterial duct closes after birth. Novel fetal MRI techniques may have a role in both understanding and accurately predicting severe neonatal CoA.

OC21.03: Dynamic fetal cardiac magnetic resonance imaging using Doppler ultrasound gating in the assessment of the fetal aortic arch: a feasibility study in comparison to fetal echocardiography

OC21.03: Dynamic fetal cardiac magnetic resonance imaging using Doppler ultrasound gating in the assessment of the fetal aortic arch: a feasibility study in comparison to fetal echocardiography

Evaluating reinforcement learning agents for anatomical landmark detection.

Automatic detection of anatomical landmarks is an important step for a wide range of applications in medical image analysis. Manual annotation of landmarks is a tedious task and prone to observer errors. In this paper, we evaluate novel deep reinforcement learning (RL) strategies to train agents that can precisely and robustly localize target landmarks in medical scans. An artificial RL agent learns to identify the optimal path to the landmark by interacting with an environment, in our case 3D images. Furthermore, we investigate the use of fixed- and multi-scale search strategies with novel hierarchical action steps in a coarse-to-fine manner. Several deep Q-network (DQN) architectures are evaluated for detecting multiple landmarks using three different medical imaging datasets: fetal head ultrasound (US), adult brain and cardiac magnetic resonance imaging (MRI). The performance of our agents surpasses state-of-the-art supervised and RL methods. Our experiments also show that multi-scale search strategies perform significantly better than fixed-scale agents in images with large field of view and noisy background such as in cardiac MRI. Moreover, the novel hierarchical steps can significantly speed up the searching process by a factor of 4-5 times.

MR imaging of subaortic and retroesophageal anomalous courses of the left brachiocephalic vein in the fetus

The purpose of this study was to report fetal cases of subaortic and retroesophageal anomalous courses of the left brachiocephalic vein (LBCV) evaluated by fetal cardiac magnetic resonance imaging (MRI). A retrospective review of 7282 fetal cardiac MRI from June 2006 to March 2017, nine cases of anomalous courses of the LBCV were correctly diagnosed by fetal cardiac MRI, one case of abnormal subaortic left brachiocephalic vein (ASLBV) missed by fetal MRI was identified postnatally during further imaging of the TOF. The diagnosis was confirmed postnatally by cardiac CT/MRI. An ASLBV was found in 8 cases, a retroesophageal LBCV was found in 2 additional cases with right aortic arch and aberrant left subclavian artery. 3 of 8 ASLBV cases were with a right aortic arch, 4 ASLBV cases had additional cardiovascular anomalies with one case isolated. 7 of 8 ASLBV and 2 retroesophageal LBCV were correctly diagnosed by fetal cardiac MRI; however fetal cardiac MRI missed 2 cases of associated pulmonary atresia (PA). Prenatal echocardiography (echo) correctly diagnosed five ASLBV and one retroesophageal LBCV as well as associated intracardiac anomalies. Fetal cardiac MRI can be a useful adjunct in the identification of subaortic and retroesophageal anomalous courses of the LBCV prenatally.

Introduction: From fetal echocardiography to fetal cardiology: A journey of over half a century.

In this Special Issue of the Journal, 8 review articles that represent the new developments and applications of fetal echocardiography and fetal cardiology for diagnosis, prognosis, and treatment of fetal cardiovascular disease are included. The goal was to provide an updated review of the evidence for the current and emerging use of fetal echocardiography and cardiac magnetic resonance, improved diagnosis of challenging congenital heart disease, new tools for evaluation of fetal systolic and diastolic function, better prognosis and risk stratification of newborns with congenital heart diseases, and new and promising therapies for fetuses with cardiovascular disease.

Fetal cardiac cine magnetic resonance imaging in utero

Fast magnetic resonance imaging (MRI) led to the emergence of ‘cine MRI’ techniques, which enable the visualization of the beating heart and the assessment of cardiac morphology and dynamics. However, established cine MRI methods are not suitable for fetal heart imaging in utero, where anatomical structures are considerably smaller and recording an electrocardiogram signal for synchronizing MRI data acquisition is difficult. Here we present a framework to overcome these challenges. We use methods for image acquisition and reconstruction that robustly produce images with sufficient spatial and temporal resolution to detect the heart contractions of the fetus, enabling a retrospective gating of the images and thus the generation of images of the beating heart. To underline the potential of our approach, we acquired in utero images in six pregnant patients and compared these with their echocardiograms. We found good agreement in terms of diameter and area measurements, and low inter- and intra- observer variability. These results establish MRI as a reliable modality for fetal cardiac imaging, with a substantial potential for prenatal evaluation of congenital heart defects.

Prenatal cardiac magnetic resonance imaging of right aortic arch with mirror image branching and retroesophageal left ductus arteriosus

Objective To evaluate the utility of fetal cardiac magnetic resonance imaging (MRI) in diagnosing right aortic arch with mirror image branching and retroesophageal left ductus arteriosus (RLDA). Methods This retrospective study included six infants diagnosed with right aortic arch with mirror image branching and RLDA postnatally by cardiac computed tomography (CT) that had fetal echocardiography (echo) and MRI initially performed. The six fetal MRI cases were examined using 1.5 T MRI unit. Steady-state free precession (SSFP) sequence and single-shot turbo spin echo (SSTSE) sequence were used to evaluate the fetal great vessels and airway. The gestational age of six fetuses at time of fetal MRI ranged from 23 to 35 weeks (mean, 26.7 weeks). Results Of six cases with mirror image right aortic arch and RLDA confirmed by postnatal CT, 4/6 were correctly diagnosed by fetal cardiac MRI and 3/6 were correctly diagnosed by prenatal echo. All six cases were not associated with other congenital heart defect. All ductus arteriosus were closed after birth. Conclusions Fetal cardiac MRI can be a useful adjunct for evaluating fetal right aortic arch with mirror-image and RLDA.

Application of MRI in prenatal diagnosis of congenital heart disease

Congenital heart disease(CHD)is one of the main causes of newborn death, which makes the prenatal diagnosis of CHD the hot spot of perinatology.Fetal echocardiography has high sensitivity in diagnosing fetal CHD in mid-gestational age of pregnancy, and is considered world-widely as the gold standard.Rapid advance has been achieved for the past decades in the technology of fetal cardiac magnetic resonance imaging(MRI). The advantages of fetal cardiac MRI including broad vision of interest and good reproducibility could make up for the deficiency of fetal echocardiography.However, some technical problems significantly limit the clinical application of it.Nowadays, fetal cardiac MRI has been utilized as a supplementary method in prenatal diagnosis of fetal CHD.This article reviews the application, advantages and limitations of fetal cardiac MRI in fetal CHD diagnosis. Key words: Fetal congenital heart disease; Fetal cardiac MRI

Utility of fetal cardiac magnetic resonance imaging to assess fetuses with right aortic arch and right ductus arteriosus

Objective: To evaluate the utility of fetal cardiac magnetic resonance imaging (MRI) to diagnose right aortic arch (RAA) with right ductus arteriosus. Methods: This retrospective study included six fetuses with right aortic arch and right ductus arteriosus. The six fetal cases were examined using a 1.5-T magnetic resonance unit. The steady-state free precession (SSFP) and single-shot turbo spin echo (SSTSE) sequences were used to evaluate the fetal heart and airway. The gestational age of the six fetuses ranged from 22 to 35 weeks (mean, 26.5 weeks). The age of the pregnant women ranged from 23 to 40 years (mean 31 years). Results: Fetal cardiac MRI diagnosed the six fetal cases with RAA with right ductus arteriosus correctly. Among the six fetuses, four were associated with other congenital heart defects. In three of six cases, the diagnoses established using prenatal echocardiography (echo) was correct when compared with postnatal diagnosis. Conclusions: Fetal cardiac MRI is a useful complementary tool to assess fetuses with RAA and right ductus arteriosus.

Self-gated fetal cardiac MRI with tiny golden angle iGRASP: A feasibility study.

To develop and assess a technique for self-gated fetal cardiac cine magnetic resonance imaging (MRI) using tiny golden angle radial sampling combined with iGRASP (iterative Golden-angle RAdial Sparse Parallel) for accelerated acquisition based on parallel imaging and compressed sensing. Fetal cardiac data were acquired from five volunteers in gestational week 29-37 at 1.5T using tiny golden angles for eddy currents reduction. The acquired multicoil radial projections were input to a principal component analysis-based compression stage. The cardiac self-gating (CSG) signal for cardiac gating was extracted from the acquired radial projections and the iGRASP reconstruction procedure was applied. In all acquisitions, a total of 4000 radial spokes were acquired within a breath-hold of less than 15 seconds using a balanced steady-state free precession pulse sequence. The images were qualitatively compared by two independent observers (on a scale of 1-4) to a single midventricular cine image from metric optimized gating (MOG) and real-time acquisitions. For iGRASP and MOG images, good overall image quality (2.8 ± 0.4 and 2.6 ± 1.3, respectively, for observer 1; 3.6 ± 0.5 and 3.4 ± 0.9, respectively, for observer 2) and cardiac diagnostic quality (3.8 ± 0.4 and 3.4 ± 0.9, respectively, for observer 1; 3.6 ± 0.5 and 3.6 ± 0.9, respectively, for observer 2) were obtained, with visualized myocardial thickening over the cardiac cycle and well-defined myocardial borders to ventricular lumen and liver/lung tissue. For iGRASP, MOG, and real time, left ventricular lumen diameter (14.1 ± 2.2 mm, 14.2 ± 1.9 mm, 14.7 ± 1.1 mm, respectively) and wall thickness (2.7 ± 0.3 mm, 2.6 ± 0.3 mm, 3.0 ± 0.4, respectively) showed agreement and no statistically significant difference was found (all P > 0.05). Images with iGRASP tended to have higher overall image quality scores compared with MOG and particularly real-time images, albeit not statistically significant in this feasibility study (P > 0.99 and P = 0.12, respectively). Fetal cardiac cine MRI can be performed with iGRASP using tiny golden angles and CSG. Comparison with other fetal cardiac cine MRI methods showed that the proposed method produces high-quality fetal cardiac reconstructions. 2 Technical Efficacy: Stage 1 J. MAGN. RESON. IMAGING 2017;46:207-217.

MR imaging of fetal cardiac malposition and congenital cardiovascular anomalies on the four-chamber view.

Fetal echocardiography is the method of choice to visualize the fetal congenital cardiovascular anomalies. However, there are some disadvantages. Fetal cardiac magnetic resonance imaging (MRI) has the potential to complement ultrasound in detecting congenital cardiovascular anomalies. This pictorial review draws on our experience about fetal cardiac MRI; it describes the four-chamber view on fetal cardiac MRI and important clues on an abnormal four-chamber view to the diagnosis of fetal congenital cardiovascular anomalies.