2019/09/28 by Abolfazl Mehranian, Colm J. McGinnity, Mehranian, Abolfazl +11
Medicine · #Advanced MRI Techniques and Applications #Cerebrovascular and Carotid Artery Diseases #Meningioma and schwannoma management
paper · pdf · doi:10.48550/arxiv.1909.13166
A model-based reconstruction framework is proposed for MOtion-Corrected and\nHigh-resolution anatomically-Assisted (MOCHA) reconstruction of ASL data. In\nthis framework, all low-resolution ASL control-label pairs are used to\nreconstruct a single high-resolution cerebral blood flow (CBF) map, corrected\nfor rigid motion, point-spread-function (PSF) blurring and partial-volume\neffect (PVE).Six volunteers were recruited for CBF imaging using PCASL\nlabelling, 2-shot 3D-GRASE sequences and high-resolution T1-weighted MRI. For\ntwo volunteers, high-resolution scans with double and triple resolution in the\npartition direction were additionally collected. Simulations were designed for\nevaluations against a high-resolution ground-truth CBF map, including a\nsimulated hyper-perfused lesion and hyper/hypo-perfusion abnormalities. MOCHA\nwas compared to standard reconstruction and a 3D linear regression (3DLR) PVE\ncorrection method and was further evaluated for acquisitions with reduced\ncontrol-label pairs and k-space undersampling. MOCHA reconstructions of\nlow-resolution ASL data showed enhanced image quality particularly in the\npartition direction. In simulations, both MOCHA and 3DLR provided more accurate\nCBF maps than the standard reconstruction, however MOCHA resulted in the lowest\nerrors and well delineated the abnormalities. MOCHA reconstruction of\nstandard-resolution in-vivo data showed good agreement with higher-resolution\nscans requiring 4x and 9x longer acquisitions. MOCHA was found to be robust for\n4x-accelerated ASL acquisitions, achieved by reduced control-label pairs or\nk-space undersampling. Conclusion: MOCHA reconstruction reduces PVE by direct\nreconstruction of CBF maps in the high-resolution space of the corresponding\nanatomical image, incorporating motion correction and PSF modelling. Following\nfurther evaluation, MOCHA should promote the clinical application of ASL.\n