Nonrigid Retrospective Respiratory Motion Correction in Whole-Heart Coronary MRA

作者：Schmidt Johannes F M; Buehrer Martin; Boesiger Peter; Kozerke Sebastian^*

来源：Magnetic Resonance in Medicine, 2011, 66(6): 1541-1549.

DOI：10.1002/mrm.22939

• coronary MRA
• motion correction
• respiratory motion
• retrospective motion correction

A nonrigid retrospective respiratory motion correction scheme is presented for whole-heart coronary imaging with interleaved acquisition of motion information. The quasi-periodic nature of breathing is exploited to populate a 3D nonrigid motion model from low-resolution 2D imaging slices acquired interleaved with a segmented 3D whole-heart coronary scan without imposing scan time penalty. Reconstruction and motion correction are based on inversion of a generalized encoding equation. Therein, a forward model describes the transformation from the motion free image to the motion distorted k-space data, which includes nonrigid spatial transformations. The effectiveness of the approach is demonstrated on 10 healthy volunteers using free-breathing coronary whole-heart scans. Although conventional respiratory-gated acquisitions with 5-mm gating window resulted in an average gating efficiency of 51% +/- 11%, nonrigid motion correction allowed for gate-free acquisitions, and hence scan time reduction by a factor of two without significant penalty in image quality. Image scores and quantitative image quality measures for the left coronary arteries showed no significant differences between 5-mm gated and gate-free acquisitions with motion correction. For the right coronary artery, slightly reduced image quality in the motion corrected gate-free scan was observed as a result of the close vicinity of anatomical structures with different motion characteristics. Magn Reson Med 66:1541-1549, 2011.

• 出版日期2011-12