Positive contrast visualization of nitinol devices using susceptibility gradient mapping

Evert-jan P.A. Vonken, Michael Schär, Matthias Stuber
2008 Magnetic Resonance in Medicine  
MRI visualization of devices is traditionally based on the signal loss due to T 2 * effects originating from the local susceptibility differences. To visualize nitinol devices with positive contrast a recently introduced post processing method is adapted to map the induced susceptibility gradients. This method operates on regular gradient echo MR images and maps the shift in k-space in a (small) neighborhood of every voxel by Fourier analysis followed by a center of mass calculation. The
more » ... ative map of the local shifts generates the positive contrast image of the devices, while areas without susceptibility gradients render a background with noise only. The positive signal response of this method depends only on the choice of the voxel neighborhood size. The properties of the method are explained and the visualization of a nitinol wire and two stents are shown for illustration.
doi:10.1002/mrm.21688 pmid:18727096 pmcid:PMC2627583 fatcat:mtprsodwsfb55odrtuhpjp2rvm