Improved respiratory self-navigation for 3D radial acquisitions through the use of a pencil-beam 2D-T2 -prep for free-breathing, whole-heart coronary MRA.
PURPOSE
In respiratory self-navigation (SN), signal from static structures, such as the chest wall, may complicate motion detection or introduce post-correction artefacts. Suppressing signal from superfluous tissues may therefore improve image quality. We thus test the hypothesis that SN whole-heart coronary magnetic resonance angiography (MRA) will benefit from an outer-volume suppressing 2D-T2 -Prep and present both phantom and in vivo results.


METHODS
A 2D-T2 -Prep and a conventional T2 -Prep were used prior to a free-breathing 3D-radial SN sequence. Both techniques were compared by imaging a home-built moving cardiac phantom and by performing coronary MRA in nine healthy volunteers. Reconstructions were performed using both a reference-based and a reference-independent approach to motion tracking, along with several coil combinations. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were compared, along with vessel sharpness (VS).


RESULTS
In phantoms, using the 2D-T2 -Prep increased SNR by 16% to 53% and mean VS by 8%; improved motion tracking precision was also achieved. In volunteers, SNR increased by an average of 29% to 33% in the blood pool and by 15% to 25% in the myocardium, depending on the choice of reconstruction coils and algorithm, and VS increased by 34%.


CONCLUSION
A 2D-T2 -Prep significantly improves image quality in both phantoms and volunteers when performing SN coronary MRA. Magn Reson Med 79:1293-1303, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
['Coristine|Andrew J|AJ|', 'Chaptinel|Jerome|J|', 'Ginami|Giulia|G|0000-0003-4669-0572', 'Bonanno|Gabriele|G|', 'Coppo|Simone|S|', 'van Heeswijk|Ruud B|RB|', 'Piccini|Davide|D|', 'Stuber|Matthias|M|']
D000328:Adult D000465:Algorithms D017023:Coronary Angiography D005260:Female D006321:Heart D006801:Humans D021621:Imaging, Three-Dimensional D018810:Magnetic Resonance Angiography D008297:Male D019047:Phantoms, Imaging
self-navigation coronary 2D T2-Prep adiabatic inner volume iterative