TY - JOUR
T1 - NOVIFAST
T2 - A Fast Algorithm for Accurate and Precise VFA MRI Mapping
AU - Ramos-Llorden, Gabriel
AU - Vegas-Sanchez-Ferrero, Gonzalo
AU - Bjork, Marcus
AU - Vanhevel, Floris
AU - Parizel, Paul M
AU - San Jose Estepar, Raul
AU - den Dekker, Arnold J
AU - Sijbers, Jan
PY - 2018/11
Y1 - 2018/11
N2 - In quantitative magnetic resonance mapping, the variable flip angle (VFA) steady state spoiled gradient recalled echo (SPGR) imaging technique is popular as it provides a series of high resolution weighted images in a clinically feasible time. Fast, linear methods that estimate maps from these weighted images have been proposed, such as DESPOT1 and iterative re-weighted linear least squares. More accurate, non-linear least squares (NLLS) estimators are in play, but these are generally much slower and require careful initialization. In this paper, we present NOVIFAST, a novel NLLS-based algorithm specifically tailored to VFA SPGR mapping. By exploiting the particular structure of the SPGR model, a computationally efficient, yet accurate and precise map estimator is derived. Simulation and in vivo human brain experiments demonstrate a twenty-fold speed gain of NOVIFAST compared with conventional gradient-based NLLS estimators while maintaining a high precision and accuracy. Moreover, NOVIFAST is eight times faster than the efficient implementations of the variable projection (VARPRO) method. Furthermore, NOVIFAST is shown to be robust against initialization.
AB - In quantitative magnetic resonance mapping, the variable flip angle (VFA) steady state spoiled gradient recalled echo (SPGR) imaging technique is popular as it provides a series of high resolution weighted images in a clinically feasible time. Fast, linear methods that estimate maps from these weighted images have been proposed, such as DESPOT1 and iterative re-weighted linear least squares. More accurate, non-linear least squares (NLLS) estimators are in play, but these are generally much slower and require careful initialization. In this paper, we present NOVIFAST, a novel NLLS-based algorithm specifically tailored to VFA SPGR mapping. By exploiting the particular structure of the SPGR model, a computationally efficient, yet accurate and precise map estimator is derived. Simulation and in vivo human brain experiments demonstrate a twenty-fold speed gain of NOVIFAST compared with conventional gradient-based NLLS estimators while maintaining a high precision and accuracy. Moreover, NOVIFAST is eight times faster than the efficient implementations of the variable projection (VARPRO) method. Furthermore, NOVIFAST is shown to be robust against initialization.
KW - Adult
KW - Algorithms
KW - Brain/diagnostic imaging
KW - Humans
KW - Image Processing, Computer-Assisted/methods
KW - Magnetic Resonance Imaging/methods
KW - Male
KW - Phantoms, Imaging
UR - http://www.scopus.com/inward/record.url?scp= 85047974312&partnerID=8YFLogxK
U2 - 10.1109/TMI.2018.2833288
DO - 10.1109/TMI.2018.2833288
M3 - Article
C2 - 29993537
SN - 0278-0062
VL - 37
SP - 2414
EP - 2427
JO - IEEE Transactions on Medical Imaging
JF - IEEE Transactions on Medical Imaging
IS - 11
M1 - 8371285
ER -