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Noncontrast peripheral MRA with spiral echo train imaging
Author(s) -
Fielden Samuel W.,
Mugler John P.,
Hagspiel Klaus D.,
Norton Patrick T.,
Kramer Christopher M.,
Meyer Craig H.
Publication year - 2015
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.25216
Subject(s) - spiral (railway) , contrast (vision) , echo (communications protocol) , sequence (biology) , spin echo , angiography , nuclear medicine , nuclear magnetic resonance , medicine , radiology , physics , mathematics , computer science , magnetic resonance imaging , optics , chemistry , mathematical analysis , computer network , biochemistry
Purpose To develop a spin echo train sequence with spiral readout gradients with improved artery–vein contrast for noncontrast angiography. Theory Venous T 2 becomes shorter as the echo spacing is increased in echo train sequences, improving contrast. Spiral acquisitions, due to their data collection efficiency, facilitate long echo spacings without increasing scan times. Methods Bloch equation simulations were performed to determine optimal sequence parameters, and the sequence was applied in five volunteers. In two volunteers, the sequence was performed with a range of echo times and echo spacings to compare with the theoretical contrast behavior. A Cartesian version of the sequence was used to compare contrast appearance with the spiral sequence. Additionally, spiral parallel imaging was optionally used to improve image resolution. Results In vivo, artery–vein contrast properties followed the general shape predicted by simulations, and good results were obtained in all stations. Compared with a Cartesian implementation, the spiral sequence had superior artery–vein contrast, better spatial resolution (1.2 mm 2 versus 1.5 mm 2 ), and was acquired in less time (1.4 min versus 7.5 min). Conclusion The spiral spin echo train sequence can be used for flow‐independent angiography to generate three‐dimensional angiograms of the periphery quickly and without the use of contrast agents. Magn Reson Med 73:1026–1033, 2015. © 2014 Wiley Periodicals, Inc.