min/patient ü should increase the throughput of MR scanning q Cardiac imaging, fMRI ü Should improve temporal resolution q Various artifacts in real acquisition ü EPI, motion, hardware
bn ibn <latexit sha1_base64="tCLG2nbXwywzwFFUoqMNNZJmas8=">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</latexit> Synthesis basis Analysis basis coefficients Concise representation comes from Adaptive basis
i <latexit sha1_base64="U7NhedCxI11UMRr+85PC6B6cwUI=">AAACGXicbVDLSsNAFJ34rPVVdelmsAgupCQq6LLoxmUF+4AmhMnkph06mYSZiVpCf8ONv+LGhSIudeXfOG2z0NYDA4dzzmXuPUHKmdK2/W0tLC4tr6yW1srrG5tb25Wd3ZZKMkmhSROeyE5AFHAmoKmZ5tBJJZA44NAOBldjv30HUrFE3OphCl5MeoJFjBJtJL9iu5yIHgc3JrofRPnD6Ni9ZyFoxkPICxUHI1+4chL0K1W7Zk+A54lTkCoq0PArn26Y0CwGoSknSnUdO9VeTqRmlMOo7GYKUkIHpAddQwWJQXn55LIRPjRKiKNEmic0nqi/J3ISKzWMA5Mcr6pmvbH4n9fNdHTh5UykmQZBpx9FGcc6weOacMgkUM2HhhAqmdkV0z6RhGpTZtmU4MyePE9aJzXntGbfnFXrl0UdJbSPDtARctA5qqNr1EBNRNEjekav6M16sl6sd+tjGl2wipk99AfW1w9mz6HH</latexit> x <latexit sha1_base64="774qhuNAFXKctSHUINibxc5Dim4=">AAAB8nicbVBNS8NAFHypX7V+VT16WSyCp5KooMeiF48VbC20oWy2m3bpZhN2X8QS+jO8eFDEq7/Gm//GTZuDtg4sDDPvsfMmSKQw6LrfTmlldW19o7xZ2dre2d2r7h+0TZxqxlsslrHuBNRwKRRvoUDJO4nmNAokfwjGN7n/8Mi1EbG6x0nC/YgOlQgFo2ilbi+iOArC7GlK+tWaW3dnIMvEK0gNCjT71a/eIGZpxBUySY3pem6CfkY1Cib5tNJLDU8oG9Mh71qqaMSNn80iT8mJVQYkjLV9CslM/b2R0ciYSRTYyTyiWfRy8T+vm2J45WdCJSlyxeYfhakkGJP8fjIQmjOUE0so08JmJWxENWVoW6rYErzFk5dJ+6zundfdu4ta47qoowxHcAyn4MElNOAWmtACBjE8wyu8Oei8OO/Ox3y05BQ7h/AHzucPV6aRSA==</latexit> X n <latexit sha1_base64="eQZvkOUKW8DFp/whBQaQiuX1XSc=">AAAB7XicbVDLSgNBEOyNrxhfUY9eBoPgKexqQI9BLx4jmAckS5idzCZj5rHMzAphyT948aCIV//Hm3/jJNmDJhY0FFXddHdFCWfG+v63V1hb39jcKm6Xdnb39g/Kh0cto1JNaJMornQnwoZyJmnTMstpJ9EUi4jTdjS+nfntJ6oNU/LBThIaCjyULGYEWye1eiYVfdkvV/yqPwdaJUFOKpCj0S9/9QaKpIJKSzg2phv4iQ0zrC0jnE5LvdTQBJMxHtKuoxILasJsfu0UnTllgGKlXUmL5urviQwLYyYicp0C25FZ9mbif143tfF1mDGZpJZKslgUpxxZhWavowHTlFg+cQQTzdytiIywxsS6gEouhGD55VXSuqgGl1X/vlap3+RxFOEETuEcAriCOtxBA5pA4BGe4RXePOW9eO/ex6K14OUzx/AH3ucPtu+PNg==</latexit> basis Wavelet basis Learned Dictionary Sparse coefficient
analytic basis or subspace ü Top-down mathematical modeling q Real world signal ü Many outliers from the global signal modeling à IS THERE SIGNAL REPRESENTATION TO DEAL WITH OUTLIERS ?
-kz -t random undersampling S L L+S CS CS uses conventional data subtraction from pre-contrast reference Automatic and improved background suppression Otazo R et al. MRM 2015 Courtesy of Ricardo Otazo
radial acquisition • Only 8 spokes/temporal frame – 48-fold acceleration L L+S Compressed sensing (S-only) Otazo R et al. MRM 2015 Courtesy of Ricardo Otazo
with 8-fold acceleration Temporal resolution = 60ms, Spatial resolution = 1.7x1.7 mm2 L+S L S Standard Motion-guided Otazo R et al. ISMRM 2014 Courtesy of Ricardo Otazo
MRI by considering outliers q More flexible model than CS, low rank q Applications: ü accelerated MRI, artifact correction q Limitation ü Computational complexity ü Still top-down basis engineering à IS THERE ULTIMATE SIGNAL REPRESENTATION ?
= X hx, e bn ibn <latexit sha1_base64="tCLG2nbXwywzwFFUoqMNNZJmas8=">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</latexit> basis 1 1 x coefficient
<latexit sha1_base64="tCLG2nbXwywzwFFUoqMNNZJmas8=">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</latexit> basis 1 1 x coefficient x = X hx, e bn(x)ibn(x) <latexit sha1_base64="erKoPFMSsbyGoza+nkJyT8tbnTk=">AAACdHicfVFNa9tAEF0pTeu4SeM2hx7awzbG4EIxUltoL4GQXnJ0of4Ay5jVauQsWa3E7qi1EfoF+Xe55WfkknNWjsC1XTqw8Hhv3szsTJhJYdDz7hx379n+8xeNg+bLw6NXx63Xb4YmzTWHAU9lqschMyCFggEKlDDONLAklDAKr39U+ug3aCNS9QuXGUwTNlciFpyhpWatmyBheBXGxaKkZ4HJExpIpuYS6Fr4RIM/IgIUMoKipmlYzlSAsMDVDIWGqCy6a8/HMtCbdSoD/a9j1mp7PW8VdBf4NWiTOvqz1m0QpTxPQCGXzJiJ72U4LZhGwSWUzSA3kDF+zeYwsVCxBMy0WLUvaccyEY1TbZ9CumL/dhQsMWaZhDazmtFsaxX5L22SY/x9WgiV5QiKPzWKc0kxpdUFaCQ0cJRLCxjXws5K+RXTjKO9U9Muwd/+8i4Yfu75X3rez6/t84t6HQ3yjpySLvHJN3JOLkmfDAgn985bhzofnAf3vdt2O0+prlN7TshGuL1HHSHCMQ==</latexit> Ideal basis should be adaptive to the input in real-time Ultimate Signal Representation for MR ?
i h ,bi(x)ie bi(x) <latexit sha1_base64="wvdFNgdWBgyp03OsXJvyc2GFH4c=">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</latexit> • Deep learning is a signal representation with automatic input adaptivity. • Extension of classical regression, CS, L+S, ALOHA, etc • More training data gives better representation à Plenary Talk on 11:00-11:20, Tues, 14th May