It also is possible to measure the density—or attenuation—of plaque on CT. In a number of studies, it has been suggested that the lipid-rich plaques (considered more dangerous) have lower CT attenuation than do the fibrous plaques (which are more stable).
However, “measuring Hounsfield values is a little problematic if you want to differentiate a single plaque,” said Dr. Achenbach. In addition, CT density is heavily influenced by the concentration of contrast in the lumen. As the contrast concentration increases, so does density.
Dr. Achenbach disclosed that he has received grant/research support from Siemens. He also is a consultant to Bristol-Myers Squibb Co. and a member of the speakers' bureau for Siemens and Bracco Diagnostics Inc.