Quantitative FLASH MRI at 3T using a rational approximation of the Ernst equation
From the half-angle substitution of trigonometric terms in the Ernst equation, rational approximations of the flip angle dependence of the FLASH signal can be derived. Even the rational function of the lowest order was in good agreement with the experiment for flip angles up to 20°. Three-dimensional maps of the signal amplitude and longitudinal relaxation rates in human brain were obtained from e