Off-Resonance Separation for Positive Contrast Imaging of Iron-Oxide Labeled Cells
Reeder S, Wieben O, Gold G, Gambhir S, Chen I, Gard C, Faranesh A
University of Wisconsin, University of Wisconsin
Detection of SPIO labeled cells with MR has traditionally relied on T2* weighted imaging to attenuate image signal, creating dark regions in the image, or negative contrast. In this work, we describe a novel positive contrast method that acquires a small number of complex images at slightly different echo shifts facilitating the separation of off-resonance spins near SPIO labeled cells from on-resonance spins. Labeled cells appear as focal bright areas that can be color coded and recombined with the on-resonance image that provides anatomical reference. Examples with SPIO labeled myoblasts are shown.