Robert Frost1, Aaron T Hess2, Thomas W Okell3, Michael A Chappell3,4, M Dylan Tisdall5,6, André J W van der Kouwe5,6, Peter Jezzard3. 1. FMRIB Centre, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom. robert.frost@ndcn.ox.ac.uk. 2. Oxford Centre for Clinical Magnetic Resonance Research, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom. 3. FMRIB Centre, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom. 4. Institute of Biomedical Engineering, University of Oxford, Oxford, United Kingdom. 5. A. A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts, USA. 6. Department of Radiology, Harvard Medical School, Boston, Massachusetts, USA.
Abstract
PURPOSE: The aim of this study was to improve robustness to motion in a vessel-encoded angiography sequence used for patient scans. The sequence is particularly sensitive to motion between imaging segments, which causes ghosting and blurring that propagates to the final angiogram. METHODS: Volumetric echo planar imaging (EPI) navigators acquired in 275 ms were inserted after the imaging readout in a vessel-encoded pseudo-continuous arterial spin labeling (VEPCASL) sequence. The effects of movement between segments on the images were tested with phantom experiments. Deliberate motion experiments with healthy volunteers were performed to compare prospective motion correction (PMC) with reacquisition versus no correction. RESULTS: In scans without motion, the addition of the EPI navigator to the sequence did not affect the quality of the angiograms in comparison with the original sequence. PMC and reacquisition improved the visibility of vessels in the angiograms compared with the scans without correction. The reacquisition strategy was shown to be important for complete correction of imaging artifacts. CONCLUSION: We have demonstrated an effective method to correct motion in vessel-encoded angiography. For reacquisition of 15 segments, the technique requires approximately 30 s of additional scanning (∼25%). Magn Reson Med 76:1420-1430, 2016.
PURPOSE: The aim of this study was to improve robustness to motion in a vessel-encoded angiography sequence used for patient scans. The sequence is particularly sensitive to motion between imaging segments, which causes ghosting and blurring that propagates to the final angiogram. METHODS: Volumetric echo planar imaging (EPI) navigators acquired in 275 ms were inserted after the imaging readout in a vessel-encoded pseudo-continuous arterial spin labeling (VEPCASL) sequence. The effects of movement between segments on the images were tested with phantom experiments. Deliberate motion experiments with healthy volunteers were performed to compare prospective motion correction (PMC) with reacquisition versus no correction. RESULTS: In scans without motion, the addition of the EPI navigator to the sequence did not affect the quality of the angiograms in comparison with the original sequence. PMC and reacquisition improved the visibility of vessels in the angiograms compared with the scans without correction. The reacquisition strategy was shown to be important for complete correction of imaging artifacts. CONCLUSION: We have demonstrated an effective method to correct motion in vessel-encoded angiography. For reacquisition of 15 segments, the technique requires approximately 30 s of additional scanning (∼25%). Magn Reson Med 76:1420-1430, 2016.
Authors: Birte U Forstmann; Gilles de Hollander; Leendert van Maanen; Anneke Alkemade; Max C Keuken Journal: Nat Rev Neurosci Date: 2016-12-15 Impact factor: 34.870
Authors: Robert Frost; Paul Wighton; F Işık Karahanoğlu; Richard L Robertson; P Ellen Grant; Bruce Fischl; M Dylan Tisdall; André van der Kouwe Journal: Magn Reson Med Date: 2019-02-28 Impact factor: 4.668
Authors: Nico U F Dosenbach; Jonathan M Koller; Eric A Earl; Oscar Miranda-Dominguez; Rachel L Klein; Andrew N Van; Abraham Z Snyder; Bonnie J Nagel; Joel T Nigg; Annie L Nguyen; Victoria Wesevich; Deanna J Greene; Damien A Fair Journal: Neuroimage Date: 2017-08-10 Impact factor: 6.556
Authors: Robert Frost; Luca Biasiolli; Linqing Li; Katherine Hurst; Mohammad Alkhalil; Robin P Choudhury; Matthew D Robson; Aaron T Hess; Peter Jezzard Journal: Magn Reson Med Date: 2019-11-07 Impact factor: 4.668
Authors: Thomas W Okell; Meritxell Garcia; Michael A Chappell; James V Byrne; Peter Jezzard Journal: Magn Reson Med Date: 2018-10-25 Impact factor: 4.668