Abstract: An implantable tissue marker incorporates a contrast agent sealed within a chamber in a container formed from a solid material. The contrast agent is selected to produce a change, such as an increase, in signal intensity under magnetic resonance imaging (MRI). An additional contrast agent may also be sealed within the chamber to provide visibility under another imaging modality, such as computed tomographic (CT) imaging or ultrasound imaging.

Abstract: The present invention provides markers and methods of using markers to identify or treat anatomical sites in a variety of medical processes, procedures and treatments. The markers of embodiments of the present invention are permanently implantable, and are detectable in and compatible with images formed by at least two imaging modalities, wherein one of the imaging modalities is a magnetic field imaging modality. Images of anatomical sites marked according to embodiments of the present invention may be formed using various imaging modalities to provide information about the anatomical sites.