A system and method for anatomical markers includes an anatomical marker. The anatomical marker includes a first material observable to a first imaging modality and a second material observable to a second imaging modality. The first material is different from the second material. The first imaging modality is different from the second imaging modality. The first and second imaging modalities obtain their images without using light in a visible spectrum. In some embodiments, the anatomical marker further includes one or more superabsorbent polymers for absorbing and containing the one or more superabsorbent polymers. In some embodiments, the anatomical marker further includes a liquid or gel including the first and second materials, wherein the liquid or gel is configured to be applied to the anatomy of the patient. In some embodiments, the anatomical markers may be used to register a medical tool to anatomy of a patient.
