@article{upm55074,
           title = {NOVIFAST: A Fast Algorithm for Accurate and Precise VFA MRI T1 Mapping},
         journal = {IEEE transactions on medical imaging},
            year = {2018},
          number = {11},
           pages = {2414--2427},
           month = {November},
          author = {Gabriel Ramos Llord{\'e}n and Gonzalo Vegas S{\'a}nchez-Ferrero and Marcus Bj{\"o}rk and Floris Vanhevel and Paul M. Parizel and Ra{\'u}l San Jos{\'e} Est{\'e}par and Arnold J. den Dekker and Jan Sijbers},
          volume = {37},
       publisher = {IEEE},
        keywords = {T1 mapping; variable flip angle; SPGR; DESPOT1; relaxometry},
        abstract = {In quantitative magnetic resonance T1 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 T1 weighted images in a clinically feasible time. Fast, linear methods that estimate T1 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 T1 mapping. By exploiting the particular structure of the SPGR model, a computationally efficient, yet accurate and precise T1 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.},
             url = {https://oa.upm.es/55074/}
}