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Rapid time‐resolved magnetic resonance angiography via a multiecho radial trajectory and GraDeS reconstruction
Author(s) -
Lee Gregory R.,
Seiberlich Nicole,
Sunshine Jeffrey L.,
Carroll Timothy J.,
Griswold Mark A.
Publication year - 2013
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.24256
Subject(s) - aliasing , trajectory , temporal resolution , computer science , signal (programming language) , frame rate , isotropy , iterative reconstruction , magnetic resonance angiography , acceleration , image resolution , contrast (vision) , nuclear magnetic resonance , voxel , magnetic resonance imaging , physics , artificial intelligence , undersampling , optics , radiology , medicine , classical mechanics , astronomy , programming language
Contrast‐enhanced magnetic resonance angiography is challenging due to the need for both high spatial and temporal resolution. A multishot trajectory composed of pseudo‐random rotations of a single multiecho radial readout was developed. The trajectory is designed to give incoherent aliasing artifacts and a relatively uniform distribution of projections over all time scales. A field map (computed from the same data set) is used to avoid signal dropout in regions of substantial field inhomogeneity. A compressed sensing reconstruction using the GraDeS algorithm was used. Whole brain angiograms were reconstructed at 1‐mm isotropic resolution and a 1.1‐s frame rate (corresponding to an acceleration factor > 100). The only parameter which must be chosen is the number of iterations of the GraDeS algorithm. A larger number of iterations improves the temporal behavior at cost of decreased image signal‐to‐noise ratio. The resulting images provide a good depiction of the cerebral vasculature and have excellent arterial/venous separation. Magn Reson Med, 2013. © 2012 Wiley Periodicals, Inc.