Wilfred W. Lam1, Charles H. Cunningham1,2
1Imaging Research, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada; 2Dept. of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
One challenge in the placement of guidewires has been tracking the devices as they are moved within the body. In MR imaging, the marker is a material with a sufficiently large magnetic susceptibility relative to tissue that creates a hypointense region in the surrounding tissue. However, the resulting black hole obscures the region that must be seen. A device is presented which can create a susceptibility marker that can be mechanically turned on and off. Hypointensity in an image of water ahead of the device was only evident when the device was configured to create the marker.