Patent Document ID: 8410779
Application ID: 12850705
Patent Status: 1

Claim One:
1. A method to generate a non-contrast magnetic resonance (MR) angiography image of an examination region of a subject, comprising the steps of: operating an MR data acquisition unit with an examination subject therein to acquire a first MR image of an examination region of the subject using a first steady state free precession (SSFP) imaging sequence comprising a plurality of repetition intervals, in which a gradient-induced phase development for unmoved and moved nuclear spins in the examination region is substantially completely rephased at an end of each repetition interval; operating the MR data acquisition unit with the examination subject therein to acquire a second MR image of the examination region using a second SSFP imaging sequence, also comprising a plurality of repetition intervals, in which the gradient-induced phase development for unmoved nuclear spins is also substantially completely rephased at an end of each repetition interval in the second imaging sequence, and in which a rest phase for moved nuclear spins exists at the end of each repetition interval of the second imaging sequence, wherein said second SSFP imaging sequence comprises a readout gradient and a rephasing gradient, and wherein operating said MR data acquisition unit to acquire said second MR image comprises inserting a time interval into said readout gradient between an end of a MR signal readout and said rephrasing gradient, before activation of said rephasing gradient, to generate said rest phase such that said rest phase destroys an SSFP signal of said moved nuclear spins; and supplying said first MR image and said second MR image to a computerized processor and, in said processor, subtracting said second MR image from said first MR image to generate a non-contrast MR angiography image of the examination region.