Peak flow velocities in the ascending aorta—real-time phasecontrast magnetic resonance imaging vs. cine magnetic resonance imaging and echocardiography

摘要

This prospective study of eight healthy volunteers evaluates peak flow velocities (PFV) in the ascending aorta using real-time phase-contrast magnetic resonance imaging (MRI) in comparison to cine phase-contrast MRI and echocardiography. Flow measurements by echocardiography and cine phase-contrast MRI with breath-holding were performed according to clinical standards. Real-time phase-contrast MRI at 40 ms temporal resolution and 1.3 mm in-plane resolution was based on highly undersampled radial fast low-angle shot (FLASH) sequences with image reconstruction by regularized nonlinear inversion (NLINV). Evaluations focused on the determination of PFV. Linear regressions and Bland-Altman plots were used for comparisons of methods. When averaged across subjects, real-time phase-contrast MRI resulted in PFV of 120±20 cm s?1 (mean ± SD) in comparison to 122±16 cm s?1 for cine MRI and 124±20 cm s?1 for echocardiography. The maximum deviations between real-time phase-contrast MRI and echocardiography ranged from –20 to +14 cm s?1 (cine MRI: –10 to +12 cm s?1). Thus, in general, real-time phase-contrast MRI of cardiac outflow revealed quantitative agreement with cine MRI and echocardiography. The advantages of real-time MRI are measurements during free breathing and access to individual cardiac cycles.