Alumina as a Computed Tomography Soft Material and Tissue Fiducial Marker

Background: The use of 3D imaging is becoming increasingly common, so too is the use of fiducial markers to identify/track regions of interest and assess material deformation. While many different materials have been used as fiducials, they are often used in isolation, with little comparison to one another. Objective: In the current study, we aim to directly compare different Computed Tomography (CT and μCT) fiducial materials, both metallic and nonmetallic. Methods: μCT imaging was performed on a soft-tissue structure, in this case heart valve tissue, with markers from eight different materials attached. Additionally, we evaluated the same markers with DiceCT stained tissue in a fluid medium. Results: All of the metallic markers generated significant artifacts, and were found unsuitable for soft-tissue μCT imaging, whereas alumina markers were found to perform the best, with excellent contrast and consistency. Conclusions: These findings support the further use of alumina as fiducial markers for soft material and tissue studies that utilize CT and μCT imaging.