Abstract 10071: Improved Accuracy of 4D Flow with Ferumoxytol in Comparison to Gadolinium Contrast for Small Children with Congenital Heart Disease

Abstract

Introduction: Cardiac magnetic resonance (CMR) now allows for time-resolved three-dimensional phase-contrast (4D flow) analysis of congenital heart disease (CHD). In infants with small vessels, the influence of contrast agent type (ferumoxytol vs. gadolinium) on 4D flow has not been investigated. Thus, we investigated the accuracy of 4D flow measurements in ferumoxytol vs. gadolinium-enhanced CMR of small CHD patients. Methods: This was a retrospective study consisting of CMR studies from CHD patients less than 20 kg who had ferumoxytol or gadolinium-enhanced 4D flow and standard phase contrast (2D-PC) flow collected. 4D flow clinical software (Arterys) was used to measure flow in great vessels, systemic veins and pulmonary veins. 4D flow accuracy was defined as % difference or correlation against conventional measurements from (2D-PC) of the same vessels. Subgroup analysis was performed on two-ventricular (2V) vs. single ventricular (1V) CHD, as well as low flows (defined as < 1.5 L/min) in 1V CHD. Results: Twenty-one ferumoxytol-enhanced and 23 gadolinium-enhanced CMR studies were included, with no difference in age (2.1 ± 1.5 vs. 2.3 ± 1.8 years, p = 0.7), patient size (0.49 ± 0.18 vs. 0.51 ± 0.16 m 2 , p = 0.67), or vessel diameter (11.4 ± 5.2 vs. 12.4 ± 5.6, p = 0.22). 10 CMR studies with 1V CHD were included. Overall, ferumoxytol-enhanced 4D flow measurements demonstrated less % difference to 2D-PC when compared to gadolinium-enhanced studies (Figure 1A). In subgroup analysis of low flows in 1V CHD, ferumoxytol-enhanced 4D flow measurements had stronger correlation to 2D-PC (Figure 1B). Conclusions: In infants, ferumoxytol-enhanced 4D flow has improved accuracy when compared to gadolinium, particularly for small vessels in 1V CHD.