Differentiating platinum coated brachytherapy seeds and gold fiducial markers with varying off-resonant frequency offsets

PURPOSE: To develop an off-resonant frequency filtered method to selectively differentiate between implanted gold fiducial markers and platinum coated brachytherapy seeds. MATERIALS AND METHODS: The magnetic susceptibilities for gold fiducial markers and brachytherapy seeds differ in magnitude and also in their signs, resulting in B₀-field inhomogeneity patterns with opposite main lobes. A pulse sequence used to localize brachytherapy seeds …