| Popis: |
Despite the wealth of information so far provided by ICUS most in vitro studies require cautious interpretation due to well-recognised limitations of studying animal models of atherosclerosis or human coronary disease in circumstances that do not accurately reflect the clinical setting. This thesis is based upon the development of a pulsatile flow system which enables the study of human coronary atherosclerotic disease by ICUS in physiological conditions which closely resemble those seen in the clinical setting. The initial chapters provide an overview of ICUS and describe the development and validation of the flow system. Chapters 3 and 4 assess the qualitative accuracy of ICUS in the assessment of the composition of atherosclerotic plaque and also the reproducibility of ICUS assessments of vessel and lumen dimensions in diseased coronary arteries. There follows a study of coronary balloon angioplasty deigned to assess the influence of procedural factors, such as balloon calibre and inflation pressure selection, and ICUS guidance on the initial success of the procedure. In the remaining chapters the concept of three-dimensional reconstruction of ICUS images is described followed by two studies describing the influence of the technical factors, which are inherent in ICUS imaging, on the accuracy of atherosclerotic plaque volume measurement and its use in assessing vascular injury following coronary balloon angioplasty. Taken together these studies have helped to provide further insights into the quantitative and qualitative accuracy of ICUS in the assessment of coronary atherosclerosis and the technical factors which may confound these analyses. Furthermore, the value of ICUS in guiding, and assessing the outcome of, coronary balloon angioplasty is clearly demonstrated. Given the close correlation of the studies to the clinical setting the findings should be expected to influence our approach to clinical ICUS studies and utilize the technique more frequently in the guidance of percutaneous coronary intervention. |
