x-ray contrast media

[jtowson@nucmed.rpa.cs.nsw.gov.au (Jocelyn Towson)]

We use an yttrium-90 silicate colloid for radiation synovectomy, and it has
been suggested that the initial placement of the needle in the joint space
should, in some cases, be checked radiographically using a little contrast
material.
However the colloid manufacturers advise that the colloid "should not be
used in conjunction with x-ray opaque contrast injections as these normally
contain EDTA or other chelating agents which may remove yttrium from the
colloid media."  Can anyone please tell me if there are suitable contrast
agents available which do not contain chelating agents?

Jocelyn Towson
Royal Prince Alfred Hospital, Sydney

jtowson@nucmed.rpa.cs.nsw.gov.au (Jocelyn Towson)