rfcontrol

This repository contains a MATLAB implementation of the approach for computing RF pulses in magnetic resonance imaging described in [1], based on a trust-region CG-Newton method for optimal control of the full time-dependent Bloch equation. Test scripts are provided to reproduce the numerical optimization and simulation results in the paper [1].

Authors:

• Christoph Aigner (christoph.aigner@tugraz.at)
• Christian Clason (christian.clason@uni-due.de)
• Armin Rund (armin.rund@uni-graz.at)

Contents

Test scripts (run these):

test_single.m          test script for single-slice example
test_multi.m           test script for multi-slice example

Routines called by the test scripts:

tr_newton.m            implements trust-region Newton method
tr_cg.m                implements trust-region conjugate gradient iteration
objfun.m               computes functional value, gradient
applyHess.m            computes action of Hessian
cn_bloch.m             solves Bloch equation using Crank-Nicolson scheme
cn_adjoint.m           solves adjoint equation using adjoint CN scheme
plot_results.m         plots optimized pulse, magnetization

Data files used by the test scripts:

z_grad_thk2_dt5.mat    binary file containing GRE gradient 

Dependencies

These routines were tested under MATLAB R2013b -- R2014b under Linux (x86_64), OS X (10.10) and Windows, but should also run under older versions. The Parallel Toolbox is used to accelerate the solution of the differential equations via parfor loops; for MATLAB versions prior to R2013b, make sure to start a matlabpool before running the scripts. If the toolbox is not installed, these loops should automatically be executed in serial. For older versions of MATLAB not implementing the parfor keyword (pre 2008a), simply replace all occurences of parfor by for in cn_bloch.m, cn_adjoint.m and applyHess.m.

License

This software is published under GNU GPLv3. In particular, all source code is provided "as is" without warranty of any kind, either expressed or implied. For details, see the attached LICENSE.

Reference

[1] C. S. Aigner, C. Clason, A. Rund and R. Stollberger:
    Efficient high-resolution RF pulse design applied to simultaneous multi-slice excitation,
    Journal of Magnetic Resonance, in press, 2015 (Preprint).

bibtex:

Please cite this work as

@article{ rfcontrol,
   author      = {Aigner, Christoph Stefan and Clason, Christian and Rund, Armin and Stollberger, Rudolf},
   title       = {Efficient high-resolution {RF} pulse design applied to simultaneous multi-slice excitation},
   journal     = {Journal of Magnetic Resonance},
   volume      = {263},
   pages       = {33--44},
   year        = {2016},
   doi         = {10.1016/j.jmr.2015.11.013}
}

If you wish to cite this implementation specifically, you can do this as

@misc{ rfcontrol,
  author = {Aigner, Christoph Stefan and Clason, Christian and Rund, Armin},
  title  = {rfcontrol},
  year   = {2015},
  doi    = {10.5281/zenodo.31187}
}