Learned regularization

Learned regularization#

A learned reconstruction replaces the hand-specified regularization term by a neural network and keeps the encoding operator and the data consistency of the iterative reconstruction. This section starts with plug-and-play reconstruction, in which a pretrained denoiser takes the place of the proximal operator of ADMM and FISTA without any training, and proceeds to an unrolled network trained through BART’s ADMM (MoDL); networks for complex multi-contrast volumes, applied patch by patch; staged and self-supervised training of an unrolled network; plug-and-play with an annealed noise level; and calibrated voxel-wise uncertainty. Learned reconstruction describes where a network enters a reconstruction.

The section additionally requires:

pip install lightning torchio monai deepinv

The first lesson downloads the DRUNet weights deepinv distributes.

Plug-and-play denoisers

Plug-and-play denoisers

MoDL, on BART’s ADMM

MoDL, on BART's ADMM

Networks for complex volumes

Networks for complex volumes

Staged training of an unrolled network

Staged training of an unrolled network

Training without a reference

Training without a reference

Annealed plug-and-play

Annealed plug-and-play

Uncertainty estimation

Uncertainty estimation