1. A method of generating 2D or 3D maps of MRI T 1 and T 2 relaxation times by acquiring 2D or 3D MRI gradient-echo images and extracting T 1 and T 2 values from said images, wherein MRI images are acquired using a combination of gradient-echo sequences including: a first 2D or 3D MRI image acquired using a SSFP-FID (Steady State Free Precession-Free Induction Decay) acquisition sequence; two further images acquired using a Dual-Echo SSFP acquisition sequence; and the T 1 and T 2 values are extracted for each image pixel or voxel from the corresponding MRI signals.