A pilot analysis of 196 participants showed that a compressed 20-minute 4D-flow MRI exam underestimated flow by approximately 3 mL/beat compared with conventional 2D phase contrast MRI.
Observational (n=196)
Yes
Does a compressed 20-minute volumetric CMR exam provide non-inferior flow and functional evaluation compared to a conventional 45-60 minute CMR exam?
A rapid 20-minute volumetric CMR exam using 4D-flow and 3D-cine shows moderate-good consistency with conventional CMR for flow measurements, supporting a large-scale non-inferiority trial.
BACKGROUND: Accurate measurements of flow and ventricular volume and function are critical for clinical decision-making in cardiovascular medicine. Cardiac magnetic resonance (CMR) is the current gold standard for ventricular functional evaluation but is relatively expensive and time-consuming, thus limiting the scale of clinical applications. New volumetric acquisition techniques, such as four-dimensional flow (4D-flow) and three-dimensional volumetric cine (3D-cine) MRI, could potentially reduce acquisition time without loss in accuracy; however, this has not been formally tested on a large scale. METHODS: 4DCarE (4D-flow MRI for cardiovascular evaluation) is a prospective, multi-centre study designed to test the non-inferiority of a compressed 20 min exam based on volumetric CMR compared with a conventional CMR exam (45-60 min). The compressed exam utilises 4D-flow together with a single breath-hold 3D-cine to provide a rapid, accurate quantitative assessment of the whole heart function. Outcome measures are (i) flow and chamber volume measurements and (ii) overall functional evaluation. Secondary analyses will explore clinical applications of 4D-flow-derived parameters, including wall shear stress, flow kinetic energy quantification, and vortex analysis in large-scale cohorts. A target of 1200 participants will enter the study across three sites. The analysis will be performed at a single core laboratory site. Pilot Results: We present a pilot analysis of 196 participants comparing flow measurements obtained by 4D-flow and conventional 2D phase contrast, which demonstrated moderate-good consistency in ascending aorta and main pulmonary artery flow measurements between the two techniques. Four-dimensional flow underestimated the flow compared with 2D-PC, by approximately 3 mL/beat in both vessels. CONCLUSIONS: We present the study protocol of a prospective non-inferiority study of a rapid cardiac MRI exam compared with conventional CMR. The pilot analysis supports the continuation of the study. STUDY REGISTRATION: This study is registered with the Australia and New Zealand Clinical Trials Registry (Registry number ACTRN12622000047796, Universal Trial Number: U1111-1270-6509, registered 17 January 2022-Retrospectively registered).
Qin et al. (2024) conducted an observational in Cardiovascular disease (n=196). Compressed 20-minute volumetric CMR exam (4D-flow and 3D-cine) vs. Conventional CMR exam (45-60 min) was evaluated on Flow and chamber volume measurements and overall functional evaluation. A pilot analysis of 196 participants showed that a compressed 20-minute 4D-flow MRI exam underestimated flow by approximately 3 mL/beat compared with conventional 2D phase contrast MRI.