RIESLING

Radial Interstices Enable Speedy Low-volume imagING (RIESLING) is a tool for reconstructing non-cartesian MRI scans. It was developed for reconstructing 3D radial center-out trajectories associated with Zero Echo-Time (ZTE) or Ultrashort Echo-Time (UTE) sequences. These trajectories provide unique challenges in efficient reconstruction compared to Cartesian trajectories (both 2D and 3D). However it is capable of reconstructing any trajectory.

Contents

Commands

RIESLING is provided as a single executable file. The riesling executable provides multiple individual commands, which are grouped into reconstruction, data manipulation, sensitivity map estimation, basis creation, linear operators, and utilities. To see a full list of commands currently available, run riesling with no arguments. Detailed help for commands can be found in the category pages: Reconstruction, Operators and Utilities. The most useful are:

riesling recon-lsq Least-squares reconstruction including sensitivity maps.
riesling recon-rlsq Regularized least-squares reconstruction, similar to bart pics.
riesling denoise Denoise an already reconstructed image.
riesling h5 Prints information about compatible .h5 files

RIESLING exploits the inherent oversampling of most non-Cartesian trajectories at the center of k-space to generate SENSE maps directly from the input data, but utilities are provided to explicitly extract sensitivities if desired. Further details can be found in Utilities.

Examples

A tutorial notebook is provided to explain the basic steps in reconstruction.

Input Data

An important step with using RIESLING is providing data in the correct .h5 format. Details of this format can be found in Data Format. Matlab and Python code to generate these files is provided in the /matlab and /python directories of the repository respectively. Users of the ZTE sequence on GE platforms should contact the authors to discuss conversion strategies.