In-vitro validation of 4D flow MRI measurements with an experimental pulsatile flow model

Abstract Purpose The purpose of this study was to assess the precision of four-dimensional (4D) phase-contrast magnetic resonance imaging (PCMRI) to measure mean flow and peak velocity (V max ) in a pulsatile flow phantom and to test its sensitivity to spatial resolution and Venc. Material and methods The pulsatile flow phantom consisted of a straight tube connected to the systemic circulation of an experimental mock circulatory system. Four-dimensional-PCMR images were acquired using different spatial resolutions (minimum pixel size: 1.5 × 1.5 × 1.5 mm 3 ) and velocity encoding sensitivities (up to three times V max ). Mean flow and V max calculated from 4D-PCMRI were compared respectively to the reference phantom flow parameters and to V max obtained from two-dimensional (2D)-PCMRI. Results 4D-PCI measured mean flow with a precision of −0.04% to + 5.46%, but slightly underestimated V max when compared to 2D-PCMRI (differences ranging from −1.71% to −3.85%). 4D PCMRI mean flow measurement was influenced by spatial resolution ( P max , neither spatial resolution nor Venc did influence the precision of the measurement. Conclusion Using an experimental pulsatile flow model 4D-PCMRI is accurate to measure mean flow and V max with better results obtained with higher spatial resolution. We also show that Venc up to 3 times higher than V max may be used with no effect on these measurements.