Inversion

In some cases, some of the analysis steps can be performed by direct inversion rather than optimization of a non-linear cost function. Direct inversion methods typically first determine relaxation rates from signals, then derive concentrations and finally fit for the parameters. Direct inversion methods are common in the literature, but they don’t always apply.

An example is the conversion from signal to concentration using steady-state sequences, which can be performed analytically for tissues with fast water exchange. Some of these methods are available as functions in dcmri (see Inverse signal models) and as optional fitting methods in end-to-end applications.

[ … coming soon …] Direct inversion methods.