Comparison of Image Acquisition Techniques in Four-Dimensional Flow Cardiovascular MR on 3 Tesla in Volunteers and Tetralogy of Fallot Patients.

Four-dimensional phase-contrast (PC) velocity-encoded flow magnetic resonance imaging (4D flow MRI) is a potentially valuable tool for studying cardiovascular hemodynamics for disease monitoring and/or treatment planning. In this study we compared the performance of two 4D flow MRI pulse sequences - echo-planar imaging (EPI) and segmented gradient-echo (turbo-field-echo or TFE on vendor's platform) - on a clinical 3T system in 6 human subjects including 3 patients with Tetralogy of Fallot (TOF). For aortic flow rate, the coefficients of variation (COV) between 2D and 4D EPI were 7.0% and 7.7% for controls and patients respectively. The corresponding COV between 2D and 4D TFE were 19.0% and 18.3% for controls and patients respectively. The COV between 4D TFE and 4D EPI were larger than 18.7% in kinetic energy analysis. 4D EPI demonstrated acceptable accuracy of intra-cardiac flow quantification, which was also shown in the ex-vivo phantom measurements.