Patent ID: 9414765
Filing Date: 2016-08-16
CPC Classification: A61B,G01R

Claim Text:
1. A magnetic resonance imaging (MRI) system comprising: an MRI gantry assembly having static magnet, gradient magnet, RF coil and patient support structures configured to define an imaging volume about a region of interest in a patient; an MRI control system connected to said MRI gantry and configured to control components thereof to effect plural magnetic resonance angiography (MRA) data acquisition sequences including cardiac triggered images associated with systolic and diastolic phases of the cardiac cycle; and image reconstruction processing and display components including at least one processor configured to reconstruct and process images of patient anatomy within said region of interest using MRI data acquired by said plural MRA data acquisition sequences and to display a plurality of resultant MRA difference images resulting therefrom; said MRI control system including at least one programmed computer processor configured to independently control at least one imaging sequence parameter so as to (1) use different flip angles of RF refocusing pulses while acquiring data for each of respectively associated systolic and diastolic phase images in each of a plurality of overall MRA data acquisition sequences, each sequence comprising a repeating plurality of first and second interleaved subsequence pairs, each subsequence including an RF excitation pulse followed by a plurality of RF refocusing pulses, wherein a first flip angle is used for the first subsequences while acquiring systolic phase images and a different second flip angle is used for the second subsequences while acquiring diastolic phase images, said first and second flip angles being unequal and thus different from each other, and (2) for at least the subsequence that acquires data for the systolic phase in successive ones of said overall MRA data acquisition sequences, configure respectively associated re-focusing flip angles according to a variable flip angle (VFA) sweep pattern.