As a luminogram, coronary angiography provides a good
overview of the coronary artery tree. Using quantitative
coronary measurements, the degree of coronary obstruction
can be determined. The limitation of coronary angiography is
that it does not provide information on the arterial wall structure
and therefore cannot assess the extent of atherosclerosis.
Knowledge about adaptive coronary remodelling processes as
compensatory enlargement of the coronary artery has focused
diagnostic interest on the non-stenotic lesions of the coronary
tree. Intravascular ultrasound (IVUS) can reveal discrepancies
between the extent of coronary atherosclerosis and
angiography imaging by in vivo plaque imaging. Spectrum
analysis of IVUS-derived radiofrequency (RF) data enables a
more detailed analysis of plaque composition and morphology.
Preliminary in vitro studies correlated four histological plaque
components with a specific spectrum analysis of the RF data.
The different components (fibrous, fibrofatty, necrotic core and
dense calcium) are colour coded. Coronary tissue maps were
reconstructed from RF data using IVUS–Virtual Histology
(VH IVUS) software (Real-Time VH, Volcano Corporation,
Rancho Cordova, California, USA). VH IVUS has the potential
to detect high-risk lesions and can provide new insights into the
pathophysiology of coronary artery disease. VH IVUS allows
the differentiation of different lesion types based on information
derived from histopathology. The in vivo specific histological
analysis of coronary atherosclerosis may allow better
stratification of treatment of patients with coronary artery
disease.