4D Flow MRI Quantification of Congenital Shunts: Comparison to Invasive Catheterization

Michael J Horowitz; Daniel F Kupsky; Howaida G El-Said; Laith Alshawabkeh; Seth J Kligerman; Albert Hsiao

doi:10.1148/ryct.2021200446

4D Flow MRI Quantification of Congenital Shunts: Comparison to Invasive Catheterization

Radiol Cardiothorac Imaging. 2021 Apr 1;3(2):e200446. doi: 10.1148/ryct.2021200446. eCollection 2021 Apr.

Authors

Michael J Horowitz¹, Daniel F Kupsky¹, Howaida G El-Said¹, Laith Alshawabkeh¹, Seth J Kligerman¹, Albert Hsiao¹

Affiliation

¹ Department of Radiology, UC San Diego Medical Center, 200 W Arbor Dr, San Diego, CA 92103 (M.J.H., S.J.K., A.H.); Division of Cardiology (D.F.K., L.A.) and Department of Pediatrics, Division of Cardiology (H.G.E.), UC San Diego, La Jolla, Calif; and Division of Cardiology, UC Los Angeles Health, Los Angeles, Calif (D.F.K.).

Abstract

Purpose: To compare invasive right heart catheterization with four-dimensional (4D) flow MRI for estimating shunt fraction in patients with intracardiac and extracardiac shunts.

Materials and methods: In this retrospective study, patients who underwent 4D flow MRI and invasive right heart catheterization with a shunt run between August 2015 and November 2018 were included. The primary objective was comparison of estimated shunt fraction (ratio of pulmonary-to-systemic flow, Q_p/Q_s) at 4D flow and catheterization. Secondary objectives included comparison of the right ventricular-to-left ventricular stroke volume ratio (RVSV/LVSV) to shunt fraction (for those with applicable shunts) and comparison of cardiac output between 4D flow and catheterization. Statistical analysis included Pearson correlation and Bland-Altman plots.

Results: A total of 33 patients met inclusion criteria (mean age, 49 years ± 16 [standard deviation]; 24 women). 4D flow measurements of Q_p/Q_s strongly correlated with those at catheterization (r = 0.938), and there was no bias. RVSV/LVSV correlated strongly with Q_p/Q_s from 4D flow (r = 0.852) and catheterization (r = 0.842). Measurements of left ventricle (Q_s) and right ventricle (Q_P) cardiac output from 4D flow and catheterization (Fick) correlated moderately overall (r = 0.673 [Q_p] and r = 0.750 [Q_s]).

Conclusion: Shunt fraction measurement using 4D flow MRI compares well with that using invasive cardiac catheterization.Supplemental material is available for this article.© RSNA, 2021.

2021 by the Radiological Society of North America, Inc.