Goncalves LF, Lindblade CL, Cornejo P, Patel MC, McLaughlin ES, Bardo DME.Pediatr Radiol. 2022 Mar;52(3):513-526. doi: 10.1007/s00247-021-05234-1. Epub 2021 Nov 29.PMID: 34842935
Take Home Message
- Fetal echocardiography was more sensitive for diagnosing cardiovascular anomalies compared to fetal MRI
- Fetal MRI was more sensitive in diagnosing extracardiac anomalies when compared to referral US.
- The additional information provided by fetal MRI can change the prognosis and counseling for fetuses with extracardiac anomalies.
Commentary from Dr. Anna Tsirka (Hartford, CT, USA), section editor of Pediatric and Fetal Cardiology Journal Watch
The objective of this study was to determine the frequency of additional structural cardiovascular and non-cardiovascular anomalies identified by fetal MRI in a population of fetuses with CHD who underwent detailed obstetrical US examinations by maternal–fetal medicine specialists and fetal echocardiography by pediatric cardiologists prior to referral.
This study was a retrospective review of 31 fetuses with CHD and known outcome who underwent fetal MRI at Phoenix Children’s hospital and had a fetal echocardiogram performed by a pediatric cardiologist. The type and frequency of cardiac and non-cardiac anomalies diagnosed by fetal echocardiography, detailed obstetrical US and fetal MRI were tabulated and compared to the final diagnoses.
Fetal MRIs were performed at a gestational age (mean ± SD) of 31.4±4.5 weeks. The gestational age at the time of fetal echocardiography was 30.2±5.4 weeks and the gestational age at the time of the referral US was 26.6±5.3 weeks.
12 fetuses had isolated CHD and 19 had additional extracardiac anomalies
Nine anomalies in seven fetuses were identified by fetal echocardiography alone (unbalanced AVC, DORV, CoA and tricuspid valve dysplasia), while 3 cardiovascular anomalies were identified by fetal MRI alone, all in the group of fetuses with both CHD and associated anomalies in other organs and systems. These included a case of double scimitar veins, a small ventricular septal defect (VSD) in a fetus with trisomy 21, duodenal atresia, left aortic arch with aberrant left subclavian artery and intestinal malrotation; and a persistent right umbilical vein. Prenatal diagnosis by MRI affected counseling in the one case of Scimitar syndrome with pulmonary sequestration.
Nineteen fetuses had an additional 48 non-cardiovascular anomalies diagnosed after birth, 37 of which were correctly diagnosed by fetal MRI compared to 14 by US. These included anomalies of the brain, lungs, spine, GI, and GU system.
4 fetuses had brain anomalies discovered by fetal MRI that changed counseling. In one case, it led to further genetic testing and diagnosis, and in one case it led to further postnatal imaging.
Pulmonary hypoplasia was diagnosed by fetal MRI in 2 fetuses who required high ventilator support and eventually died. Another fetus with heterotaxy and complex CHD was diagnosed with pulmonary lymphangiectasia, which was confirmed postnatally and decision was made to withdraw support.
Five fetuses had anomalies missed by both the referral US and fetal MRI, while 4 fetuses had false positive findings by MRI
This study showed that fetal MRI detects a significantly larger number of previously unknown anomalies of other organ systems, primarily the brain and lungs in fetuses with prenatally diagnosed CHD.
The information provided by fetal MRI may change prognosis and counseling and may be considered as a useful tool in fetuses with complex CHD.
Fetal echocardiography remains the gold standard for diagnosing fetal cardiac disease.