Cardiovascular diseases are the leading cause of mortality and morbidity in the current era. Current guidelines base their recommendations for diagnosis and management of cardiovascular diseases on... Show moreCardiovascular diseases are the leading cause of mortality and morbidity in the current era. Current guidelines base their recommendations for diagnosis and management of cardiovascular diseases on several important parameters such as left ventricular (LV) dimension and function, presence of coronary artery disease (CAD) and valve function. Accurate assessment of these parameters is therefore essential for patients with or at risk of cardiovascular diseases and requires the use of invasive and non-invasive testing. Non-invasive testings are in principle preferable, especially for a first-line approach, being safer and generally widely available and easy to perform. The present thesis highlights the use of non-invasive imaging modalities, namely cardiac computed tomography and advanced echocardiography analysis (speckle tracking and calibrated integrated backscatter) to diagnosis and guide the treatment of various cardiovascular diseases. Show less
The primary objective of this dissertation is to determine the diagnostic performance of 320-row CTA for cardiac applications, particularly in the assessment of significant coronary stenosis in... Show moreThe primary objective of this dissertation is to determine the diagnostic performance of 320-row CTA for cardiac applications, particularly in the assessment of significant coronary stenosis in patients with known or suspected CAD. It was shown that 320-row CTA allows accurate, non-invasive assessment of significant CAD and global left ventricular function in patients with suspected CAD, as well as in patients with a history of revascularization. Furthermore, the prognostic value of CTA and its role in clinical management of patients with suspected CAD were investigated. The potential of CTA to serve as a gatekeeper prior to CTA was explored. It was shown that CTA has the potential to serve as a gatekeeper for invasive coronary angiography in patients with a low-to-intermediate pre-test likelihood of obstructive CAD. Subsequently, it was shown that the assessment of left ventricular function analysis on CTA may further enhance risk stratification beyond the assessment of degree of stenosis. Finally, in patients with type 2 diabetes mellitus, the combined presence of increased waist circumference and elevated plasma triglyceride levels was shown to translate into an increased likelihood of CAD on CTA and may therefore serve as a practical clinical biomarker to improve risk stratification. Show less
In this thesis the assessment of ultrasonography (US) and Computed Tomography (CT) in the diagnostic strategy of suspected appendicitis is presented. The first study showed that focused single... Show moreIn this thesis the assessment of ultrasonography (US) and Computed Tomography (CT) in the diagnostic strategy of suspected appendicitis is presented. The first study showed that focused single-detector helical CT as well as graded compression US performed in a general community teaching hospital by both body imaging radiologists and general radiology staff members have a similar accuracy for the diagnosis of acute appendicitis. A second study showed that in interpreting CT images the expertise of the attending radiologist should be considered. A third study showed that gender seems to affect the accuracy of US and CT in patients suspected of acute appendicitis. A fourth study showed that US as a sole imaging tool is of limited value both in women with unequivocal and in women with equivocal signs of appendicitis. A fifth study showed that US and CT implemented in a diagnostic pathway yields a high diagnostic accuracy for acute appendicitis without adverse events due to delay in treatment. A sixth study showed that for a majority of the surgeons, the diagnosis of acute appendicitis is based on clinical signs and symptoms. US and CT can be valuable in diagnosing appendicitis but further cooperation between surgeons and radiologists is required. Show less
Various non-invasive imaging techniques are available for the diagnosis of coronary artery disease (CAD). Multi-slice computed tomography (MSCT) is an upcoming technique that allows direct... Show moreVarious non-invasive imaging techniques are available for the diagnosis of coronary artery disease (CAD). Multi-slice computed tomography (MSCT) is an upcoming technique that allows direct visualization of the coronary arteries. Apart from the assessment of atherosclerosis, MSCT can also provide important information on the global and regional left ventricular (LV) function. However, it should be realized that the hemodynamic consequences of atherosclerosis can not be obtained by MSCT imaging, and that functional testing, with for example nuclear imaging, will remain necessary to determine therapeutic strategy. CAD is the most common cause of chronic heart failure. Recently, cardiac resynchronization therapy (CRT) has become implemented in the treatment of patients with severe heart failure. Although the improvement in systolic function after CRT implantation can be considerable, 20% to 30% of patients do not respond to CRT. It has been shown that the presence of LV dyssynchrony is an important predictor of response to CRT. Gated SPECT allows not only the assessment of myocardial perfusion (scar tissue and viable myocardium) but also the evaluation of LV dyssynchrony. As many patients with heart failure undergo nuclear imaging with SPECT, integrated assessment of LV dyssynchrony, viability and scar tissue may be an attractive option. Show less
