Localization of brachytherapy seeds in MRI by deconvolution

MRI has the potential to be used as a preferred imaging method for brachytherapy during the seed insertion and post-surgery evaluation. However, the brachytherapy seeds usually appear dark in the MRI magnitude images. Previously, we have developed a method based on susceptibility mapping to generate positive contrast of the seeds, which allows improved seed localization. In this paper, we propose a new method to localize the seeds by deconvolution using a seed kernel (i.e. the calculated magnetic field surrounding a seed). The deconvolution is solved using a regularized L₁ minimization. Results from simulated and experimental data sets show that the seeds can be identified and localized using the proposed method more precisely.