Due to their relative insensitivity to B1 inhomogeneities, Look-Locker methods are widely used for the quantification of T1 relaxation time. One such Look-Locker method, TAPIR, has been demonstrated with several clinical applications and has been shown to be faster than conventional gradient-echo sequences. However, it still requires a considerable acquisition time for whole-brain imaging. To overcome this limitation, a much faster method, ir-EPIK, has been presented in our earlier work. This work aims to perform a quantitative assessment of ir-EPIK in comparison to TAPIR using phantom data and twenty data sets from subjects. All data were acquired at 3T.