A 22-year-old G2P1 female presented to our institution at 22 weeks for fetal cardiology evaluation of hypoplastic left heart syndrome (HLHS) with mitral stenosis and aortic atresia. Fetal echocardiogram confirmed the diagnosis and suggested a severely restricted atrial septum with a pulmonary venous forward/reverse time-velocity integral ratio (VTI) of 2.7. At 29 weeks' gestation, she underwent a fetal CMR to evaluate for pulmonary lymphangiectasia and interatrial septum. Fetal cardiac gating was obtained with an MR-compatible Doppler ultrasound device (Smartsync, Northh Medical) and imaging was performed at 3T. In addition to the findings of HLHS, findings at fetal CMR included an intact/severely restrictive atrial septum with markedly dilated pulmonary veins. Additionally, there was an anomalous pulmonary vein connecting the right sided pulmonary veins to both the azygos vein and the SVC. 4D flow MRI quantified the distribution of blood flow, demonstrated a similar pulmonary venous forward/reverse flow ratio of 2.4 and visualized the anomalous vessel decompressing the pulmonary venous system into the systemic venous system. There was a segmental pattern of pulmonary lymphangiectasia, present in the right middle lobe and lingula. Same day fetal echocardiography also confirmed the anatomical findings. The patient was determined not to be a candidate for fetal intervention and following counselling, the family elected for comfort care at delivery. After delivery, the baby did not demonstrate clinical signs of a restrictive atrial septum, despite an atrial septal gradient of 11mmHg by echocardiography, and following re-evaluation, underwent a staged single ventricle palliation. At surgery for stage 1 (Norwood-Sano), the atrial septum was found to be almost intact. The infant continues to do well and currently is status post stage 2 with a superior cavopulmonary anastomosis. This case demonstrates the use of fetal CMR with an MR compatible doppler ultrasound device in the fetal evaluation of HLHS with a suspected restrictive atrial septum. In this case, fetal CMR with 4D flow was able to calculate a pulmonary venous forward/reverse flow ratio similar to echocardiography and demonstrated the anomalous pulmonary venous drainage pathway, which likely accounted for the absence of the expected severe manifestations of an intact atrial septum in addition to the relatively mild manifestations of pulmonary lymphangiectasia. Read More

Meeting name: SPR 2025 Annual Meeting , 2025

Authors: Fuentealba Cargill Andrea, Friesen Richard, Barker Alex, Fujiwara Takashi, Englund Erin, Park Sungho, Londono Obregon Camila, Browne Lorna

Keywords: 4D Flow, Pulmonary Venous Return, Cardiac MRI

A 29-year-old female (G6P4) was referred to our center following identification of thoracoomphalopagus conjoined twins, with fused heart and liver, at 20 weeks of gestation. Fetal echocardiogram and fetal cardiac MR (CMR) were performed at 21 weeks gestation to evaluate potential for post-natal repair. Fetal CMR was performed at 1.5 Tesla using an MRI compatible fetal doppler ultrasound (DUS) device (smart-sync, Northh imaging) for cardiac gating. Protocol included multiplanar cine SSFP sequences and multiplanar blackblood sequences. Fetal echocardiography and CMR were used together to understand the complex anatomical arrangements. Each twin had 2 sets of atria (with an interatrial connection) but only a single ventricle. Twin A had a left ventricle, pulmonary atresia and MAPCAs. Twin B had a right ventricle had coarctation of the aorta, bilateral SVCs and partial anomalous pulmonary venous return. After counselling regarding the grave prognosis of both twins, the patient decided to deliver at her local hospital with comfort care. Teaching Points from this Case This case of conjoined twins at 21 weeks gestation, is the youngest example of successful clinical DUS fetal CMR. In this case, fetal CMR was used to demonstrate the great vessel anatomy and was fundamental in ascertaining the absence of a path to successful surgical palliation for either twin. Additionally, fetal CMR was used as the primary modality during patient counselling to explain the anomalies. The high degree of diagnostic certainty that the fetal CMR facilitated, allowed the family to avoid the unnecessary emotional and financial expense that relocation for delivery would have incurred and facilitated palliative care at their local center. Read More

Meeting name: SPR 2025 Annual Meeting , 2025

Authors: Fuentealba Cargill Andrea, Friesen Richard, Fujiwara Takashi, Park Sungho, Arguello Fletes Gladys, Englund Erin, Barker Alex, Londono Obregon Camila, Browne Lorna

Keywords: Fetal MRI, Cardiac MRI, 4D Flow