Variable-Density Spiral Design Functions

Introduction

Spiral k-space scanning is an important research area in MRI. There are numerous references for designing spiral gradient waveforms, including Meyer (1992), King (1995), Pipe (1999), and Glover (1999). I included a brief description of spiral waveform design in my thesis - Section 6.2.1 .

An example application using these waveforms is described in J.H. Lee et al., Fast 3D Imaging using Variable-Density Spiral Trajectories with Application to Limb Perfusion Magnetic Resonance in Medicine 50(6): 1276-1285 (December 2003).

This page contains code for Matlab design of variable-density spiral waveforms, a slightly-expanded version of what is described in the above PDF file. A sample variable-density spiral is shown below. You are welcome to use this code for anything you wish!

(Click on image to enlarge)

Functions Included

The tar file includes numerous .m scripts, and a .c code that can be compiled to a .mex function.

vds.m -- Matlab script version of variable-density spiral design. Supporting function is q2r21.m.
vdsmex.m -- Matlab script wrapper for vds_mex.c, which is newer, faster and hopefully better than vds.m.
vds_mex.c -- Mex interface to C-code in vds.c
vds.c -- C-functions to generate variable-density spirals.
vds_mex.mexglx -- Compiled Mex code for linux.
vdsexample.m -- Example use of vdsmex.m or vds.m
calcgradinfo.m/plotgradinfo.m -- Plotting functions.

Download Instructions

Save the tar file, vdspiral.tar.gz to your computer. To extract the files, execute "tar -xzvf vdspiral.tar.gz" from the directory where you have saved the file.

For a very simple design, simply type, "g = vdsmex(20)" in Matlab.

Comments

Please report comments/bugs with this code to Brian Hargreaves.