View Full Version : Seeking Advice: Small marker (<1mm diameter) visible in both MRand CT

Jd Johnston
09-20-2006, 05:51 AM
Dear BIOMCH-L subscribers,

I am seeking some advice regarding small markers (~1mm diameter) which can
be observed via both CT and MR imaging. I would like to do some validation
studies on our registration system which shape matches CT and MR derived 3D
structures, and would ideally use a small marker which could be taken to
represent a single xyz point in space. A number of these points would then
be used to assess the accuracy of the registration algorithm(s).

Tantalum bead won't work due to the magnets, and I think that low magnetic
SS beads would cause distortion w/ the MR. We have used pills (~5mm
diameter) containing oil (Cod Liver I think), and small ink tubes containing
water and they worked sufficiently well, but I'm looking for something a lot
smaller and was hoping that the BIOMCH-L community might have some

Thanks in advance,

JD Johnston

James D. Johnston, MSc
PhD Candidate
University of British Columbia
Division of Orthopaedic Engineering Research
5th Floor, 828 West 10th Avenue
Vancouver, BC V5Z 1L8
phone: 604-839-1174
fax: 604-875-4851
email: jdj@interchange.ubc.ca