Abstract
The composition of artherosclerotic plaque can be distingushed from the normal physical properties of tissues by the inflammatory mediators and the cells' remodelling arterial walls, and can therefore be demonstrated by imaging methods. Imaging of the vulnerable atherosclerotic plaque is now accepted as the main target in the diagnostics of imminent acute complications in atherosclerosis.
Recent results of clinical trials (Ross's, CAPTIM, Prague) suggest facilitated intervention - primary angioplasty together with pre-hospital fibrinolysis during transportation - as the urgent therapeutical method of choice. This life-saving emergency treatment is considered to be invasive because of the angiography and intravascular ultrasonography.
Angiography ranges from digital subtraction angiography to three-dimensional imaging, together for example with the rotational acquisition of angiographic pictures. X-ray densitometry of the atherosclerotic plaque tissues is also a promising method for differentiation.
In contrast, intravascular ultrasonography, by the direct use of varying frequencies, allows the differentiation of tissues, and the demonstration of their relationship by virtual histology. The plaques liable to rupture (unstable vulnerable plaques) contain a large lipid core covered by a thin fibroplastic cap layer with a number of macrophages and mastocytes, and it seems that they, the plaques, can be identified by a so called new "gold-standard" modality.
The usefulness of invasive methods is not only in distinguishing pathological processes or the location and size of the atherosclerotic plaque and its calcified parts, but in attracting attention to the extent of its vulnerability. The response to therapy of the arterial wall can also be demonstrated.