Abstract
Flow jets containing velocities up to 5β7 m/s are common in patients with congenital defects and patients with valvular disease (stenosis and regurgitation). The quantitation of peak velocity and flow volume in these jets is clinically significant but requires specialized imaging sequences. Conventional 2DFT phase contrast sequences require lengthy acquisitions on the order of several minutes. Conventional spiral phase contrast sequences are faster, but are highly corrupted by flow artifacts at these high velocities due to phase dispersion and motion during the excitation and readout. A new prospectively gated method based on spiral phase contrast is presented, which has a sufficiently short measurement interval (<4 ms) to minimize flow artifacts, while achieving high spatial resolution (2 Γ 2 Γ 4 mm^3^) to minimize partial volume effects, all within a single breathhold. A complete singleβslice phase contrast movie loop with 22 ms true temporal resolution is acquired in one 10βheartbeat breathhold. Simulations indicate that this technique is capable of imaging throughβplane jets with velocities up to 10 m/s, and initial studies in aortic stenosis patients show accurate in vivo measurement of peak velocities up to 4.2 m/s (using echocardiography as a reference). Magn Reson Med 50:366β372, 2003. Β© 2003 WileyβLiss, Inc.