Use of Fetal Magnetic Resonance Imaging After Sonographic Identification of Major Structural Anomalies.
OBJECTIVES
To characterize population-based use of fetal magnetic resonance imaging (MRI) incorporating recent American College of Radiology (ACR)-Society of Perinatal Radiologists (SPR) guidelines about fetal anomalies for which MRI may provide valuable additional information when sonography is limited.


METHODS
We conducted a retrospective review of nonreferred singleton pregnancies that received prenatal care and had prenatal sonographic diagnosis of 1 or more major structural anomalies at our hospital between January 2010 and May 2018. Detailed sonography was performed in all anomaly cases. Fetal anomaly information was obtained from a prospectively maintained database, and medical records were reviewed to determine the rationale for why MRI was or was not performed, according to the indication.


RESULTS
A total of 104,597 singleton pregnancies underwent sonographic assessments of anatomy at our institution during the study period. Major structural anomalies were identified in 1650 (1.6%) of these pregnancies. Potential indications for fetal MRI per ACR-SPR guidelines were identified in 339 cases. However, fetal MRI was performed in only 253 cases, 15% of those with major anomalies and 75% with a potential indication. Magnetic resonance imaging was not performed in 41 (20%) of identified pregnancies because of an improved prognosis on serial sonography (36), because of a poor prognosis (3), or because it would not alter management (2).


CONCLUSIONS
Fetal MRI was used in 15% of those pregnancies with prenatal diagnosis of a major structural anomaly. This amounted to fewer than 0.3% of singleton deliveries. Judicious application of ACR-SPR guidelines in the context of serial sonography results in a relatively small number of fetal MRI examinations in a nonreferred population.
['Herrera|Christina L|CL|https://orcid.org/0000-0002-6484-9850', 'Byrne|John J|JJ|', 'Clark|Haley R|HR|', 'Twickler|Diane M|DM|', 'Dashe|Jodi S|JS|https://orcid.org/0000-0002-0852-5448']
D005260:Female D006801:Humans D008279:Magnetic Resonance Imaging D011247:Pregnancy D011295:Prenatal Care D011296:Prenatal Diagnosis D012189:Retrospective Studies D016216:Ultrasonography, Prenatal
magnetic resonance imaging fetal anomaly fetal magnetic resonance imaging, prenatal diagnosis obstetric ultrasound