Rapid flow quantification using non-cardiac-synchronized magnetic resonance imaging

Magnetic resonance imaging (MRI) was used to non-invasively measure arterial blood-flow rate (ABFR) accurately and rapidly. First, the basic principles of MRI, especially related to measuring ABFR, are described. The developed method called non-cardiac-synchronized (ungated) spiral phase-contrast (USPC) is presented as an MRI technique for measuring ABFR. USPC enables rapid scan and eliminates the need for cardiac-synchronization. Spiral k-space trajectories significantly reduce flow artifacts that may arise from non-cardiac-synchronization. This superior behavior of spiral trajectories is analyzed in an extended 3D-space called (kx, ky, time)-space. Finally, the results from flow-pump experiments and in vivo applications in four different vascular regions are presented. The analyses and experimental results show that using USPC, various ABFRs can be measured non-invasively and accurately within a few seconds.