FIGURE 1.

A, Standard MR parameter mapping is typically comprised of two separate steps, including one step to generate a dynamic multi-contrast image series and the next step to fit the dynamic images into a signal model to generate parameters of interest. B, MR parameter mapping can also be performed by combining the two separate steps into a model-based reconstruction framework, in which MR parameter maps can be directly estimated from undersampled dynamic k-space. A variable-density Cartesian undersampling scheme at a 4-fold acceleration is demonstrated in this schematic example