ABSTRACT
In a comparative study of the histology and in vivo MSCT imaging of large carotid plaques in patients who underwent carotid endarterectomy, CT scanning was able to distinguish between lipid tissue that had a mean attenuation value of 39±12HU and fibrous tissue with a mean value of 90±24HU10. Schroeder et al. were the first to demonstrate that distinction between lipid and fibrous plaques was also possible in smaller coronary plaques2. These results were confirmed by the study of Leber et al. who, in a elegant study, demonstrated that the density measurements between lipid and fibrous plaques were different11(Table 6.1). Both studies correlated the coronary lesion echogenicity of intravascular ultrasound (IVUS) and computed tomography density measurement, thereby taking IVUS as the reference standard to distinguish between lipid and fibrous tissue. It is of note that IVUS does not equate with histology; however, it is the best possible assumption in the setting of in vivo coronary plaque imaging.
