Imaging ferromagnetic tracers with an ac biosusceptometer

The aim of this work was to study the feasibility of obtaining images of th e distribution of ferromagnetic tracers using an ac biosusceptometer (ACB). The images were generated by mapping the response of the ACB at short dist ances due to the presence of a ferrite powder dispersed in a planar gel mat rix with different shapes. The ACB was scanned over the sample and the volt ages generated by the variation in ferrite concentration were sampled. Meth ods to render and image the distribution of ferromagnetic particles were st udied. The generalized Wiener parametric method gave the best results. The system has a potential to be used in functional images of the gastrointesti nal tract where a moderate resolution is required. We conclude that this bi omagnetic method can be successfully used to generate planar functional ima ges of magnetic particles in the near field. (C) 2000 American Institute of Physics. [S0034-6748(00)02406-0].