Pulmonary MRA During Pregnancy: Early Experience With Ferumoxytol.

Background: Ferumoxytol, an intravenous iron supplement, is commonly used to treat anemia in pregnancy. Ferumoxytol-enhanced magnetic resonance angiography (Fe-MRA) is a viable off-label alternative to gadolinium-enhanced MRA for assessment of pulmonary embolism (PE) in pregnancy.
Purpose: To describe our clinical experience with Fe-MRA in pregnant women with suspected PE.
Study Type: Retrospective, observational, cohort.
Population: A total of 98 Fe-MRA exams (consecutive sample) performed in 94 pregnant women.
Field Strength/sequence: A 1.5 T and 3.0 T, 3D T1-weighted MRA.
Assessment: After IRB approval including a waiver of informed consent, electronic health records were reviewed retrospectively for all Fe-MRA exams performed at our institution in pregnant between January, 2017 and March, 2022. The Fe-MRA protocol included 3D-MRA for assessment of pulmonary arteries, and T1-weighted imaging for ancillary findings. Fe-MRA exam duration was measured from image time stamps. Fe-MRA exams were reviewed by three cardiovascular imagers using a 4-point Likert scale for image quality and confidence for PE diagnosis (score 4 = best, 1 = worst), and tabulation of ancillary findings.
Statistical Tests: Continuous data are presented as mean ± standard deviation. The overall image quality and confidence score is given as the mean of three readers.
Results: The 98 Fe-MRA exams were performed in 94 pregnant women (age 30 ± 6, range 19-48 years, gestational week 23 ± 10, range 3-38 weeks), with four undergoing two Fe-MRA exams during their pregnancy. Median Fe-MRA exam durration was 8 minutes (interquantile range 6 minutes). Overall image quality score was 3.3 ± 0.9. Confidence score for diagnosing PE was 3.5 ± 0.8. One subject was positive for PE (1/94, 1%); 42 of the 94 (45%) subjects Fe-MRA had ancillary findings including hydronephrosis or pneumonia.
Conclusion: Ferumoxytol enhanced MRA is a radiation- and gadolinium-free alternative for diagnosis of PE during pregancy.
Evidence Level: 4 TECHNICAL EFFICACY: Stage 5.
(© 2022 The Authors. Journal of Magnetic Resonance Imaging published by Wiley Periodicals LLC on behalf of International Society for Magnetic Resonance in Medicine.)