Quantitative imaging in cardiovascular CT angiography

In de afgelopen decennia is computertomografie (CT) een prominente niet-invasieve modaliteit om hart- en vaatziekten te evalueren geworden. Dit proefschrift heeft als doel de rol van CT in de therapeutische behandeling van coronaire hartziekte (CAD) en klepaandoeningen te onderzoeken.De relatie tussen kransslagadergeometrie (statisch en dynamisch) en aanwezigheid en omvang van CAD met CT werd onderzocht. De resultaten suggereren dat de statische geometrie van de kransslagader significant gerelateerd is aan de aanwezigheid van plaque en stenose. Er was echter geen verband tussen dynamische verandering van de coronaire arterie-geometrie en de ernst van CAD. Een algoritme om de invloed van intraluminair contrastmiddel op niet-verkalkte atherosclerotische plaque Hounsfield-Unit-waarden te corrigeren werd gepresenteerd en gevalideerd met behulp van fantomen.Diagnose en operatieplanning kunnen cruciale gevolgen hebben voor de klinische uitkomst van chirurgische ingrepen. In dit proefschrift wordt beschreven dat halfautomatische softwareprogramma’s het kwantificeren van het aortaklepgebied betere reproduceerbare resultaten toonden in vergelijking met handmatige metingen, en vergelijkbare resultaten met de huidige gouden standaard, de echocardiografie. Een systematische review over het dynamische gedrag van de aorta-annulus toont aan dat de vorm van de aorta-annulus tijdens de hartcyclus verandert, wat impliceert dat er bij het bepalen van een prothese rekening moet worden gehouden met meerdere fasen. Een andere review beschrijft het gebruik van 3D-printen in de chirurgische planning samen met andere toepassingen voor de behandeling van hartklepaandoeningen.CT is de belangrijkste beeldvormingsmodaliteit in deze onderzoeken, die gericht waren op de therapeutische behandeling van hart- en vaatziekten, van vroege risicobepaling tot diagnose en chirurgische planning.In the recent decades computed tomography (CT) has emerged as a dominant non-invasive modality to evaluate cardiovascular diseases. This thesis aimed to explore the role of CT in the therapeutic management of coronary artery disease (CAD) and valvular diseases.The relationship between both static and dynamic coronary artery geometry and presence and extent of CAD using CT was investigated. The results suggest that the static coronary artery geometry is significantly related to presence of plaque and significant stenosis. However, there were no such relationship between dynamic change of coronary artery geometry and severity of CAD. As part of this thesis an algorithm to correct the influence of lumen contrast enhancement on non-calcified atherosclerotic plaque Hounsfield-Unit values was presented. The algorithm was validated using phantoms. The diagnosis and surgical planning may have crucial impact on clinical outcome. Semi-automatic software for aortic valve area quantification presented in this thesis was proven to be more repeatable and similar to gold standard echocardiography in comparison to manual measurements. The systematic review regarding the dynamic behavior of aortic annulus revealed that aortic annulus geometry changes throughout the cardiac cycle which implies that multiple phases should be taken into account for prosthesis sizing. Another review in this thesis discusses the use of 3D printing in the surgical planning along with other applications for the treatment of valvular diseases.CT is the main imaging modality in these studies which were focused on the therapeutic management of cardiovascular diseases from early risk determination to diagnosis and surgical planning

Clinical quantitative cardiac imaging for the assessment of myocardial ischaemia

Cardiac imaging has a pivotal role in the prevention, diagnosis and treatment of ischaemic heart disease. SPECT is most commonly used for clinical myocardial perfusion imaging, whereas PET is the clinical reference standard for the quantification of myocardial perfusion. MRI does not involve exposure to ionizing radiation, similar to echocardiography, which can be performed at the bedside. CT perfusion imaging is not frequently used but CT offers coronary angiography data, and invasive catheter-based methods can measure coronary flow and pressure. Technical improvements to the quantification of pathophysiological parameters of myocardial ischaemia can be achieved. Clinical consensus recommendations on the appropriateness of each technique were derived following a European quantitative cardiac imaging meeting and using a real-time Delphi process. SPECT using new detectors allows the quantification of myocardial blood flow and is now also suited to patients with a high BMI. PET is well suited to patients with multivessel disease to confirm or exclude balanced ischaemia. MRI allows the evaluation of patients with complex disease who would benefit from imaging of function and fibrosis in addition to perfusion. Echocardiography remains the preferred technique for assessing ischaemia in bedside situations, whereas CT has the greatest value for combined quantification of stenosis and characterization of atherosclerosis in relation to myocardial ischaemia. In patients with a high probability of needing invasive treatment, invasive coronary flow and pressure measurement is well suited to guide treatment decisions. In this Consensus Statement, we summarize the strengths and weaknesses as well as the future technological potential of each imaging modality

Reconstruction of coronary arteries from X-ray angiography: A review.

Despite continuous progress in X-ray angiography systems, X-ray coronary angiography is fundamentally limited by its 2D representation of moving coronary arterial trees, which can negatively impact assessment of coronary artery disease and guidance of percutaneous coronary intervention. To provide clinicians with 3D/3D+time information of coronary arteries, methods computing reconstructions of coronary arteries from X-ray angiography are required. Because of several aspects (e.g. cardiac and respiratory motion, type of X-ray system), reconstruction from X-ray coronary angiography has led to vast amount of research and it still remains as a challenging and dynamic research area. In this paper, we review the state-of-the-art approaches on reconstruction of high-contrast coronary arteries from X-ray angiography. We mainly focus on the theoretical features in model-based (modelling) and tomographic reconstruction of coronary arteries, and discuss the evaluation strategies. We also discuss the potential role of reconstructions in clinical decision making and interventional guidance, and highlight areas for future research

IAEA Atlas of Cardiac PET/CT

This open access book presents a wide portfolio of examples of positron emission tomography coupled with computer tomography (PET/CT) studies in various cardiac conditions in order to provide a rationale for the implementation of this technology in an array of clinical conditions. Cardiovascular diseases are a major contributor to premature morbidity and mortality worldwide. Low- and middle-income countries (LMICs) are particularly affected by cardiovascular diseases (CVDs), with more than 75% of all CVDs deaths occurring in these countries. For this reason, target 3.4 of the United Nations (UN) Sustainable Development Goals (SDGs) agenda aims at a 30% reduction in premature mortality due to non-communicable diseases (NCDs), which include CVDs, by 2030. Among CVDs, ischemic heart disease (IHD) plays an important role and, according to the Institute for Health Metrics and Evaluation (IHME), it was responsible for 15.96% of global deaths in 2017. Between 2000 and 2017, the number of IHD deaths worldwide increased by 0.26% per year. Several imaging tools help to non-invasively diagnose, stratify risk and guide management in cardiac disease. They include nuclear cardiology techniques, using either SPECT (single photon emission computed tomography) or PET/CT. While myocardial imaging with SPECT has been fully embraced by the cardiology community and is widely available worldwide, PET/CT introduction has been slower, due not only to its higher costs, but also to the limited availability of PET/VCT scanners, mostly utilized for oncological applications. This book is an invaluable tool for nuclear medicine physicians, cardiologists and radiologists

Optimizing Non-Invasive Detection of Coronary Artery Disease and Effects of Advanced Interventional Techniques for Patients with Stable Coronary Artery Disease:It is All about Myocardial Perfusion

The aim of this thesis was to (1) further optimize non-invasive detection of hemodynamically significant coronary artery disease (CAD) with coronary computed tomography angiography (CCTA) and myocardial perfusion imaging (MPI) and to examine (2) the effect of implantation of the bioresorbable vascular scaffold (BVS) and (3) chronic total occlusion percutaneous coronary intervention (CTO PCI). Part I showed that angiographic characteristics such as volumetric measures as well as morphological aspects of atherosclerosis as assessed by CCTA are of interest when considering the hemodynamic consequences of atherosclerosis. These findings add to luminal stenosis grading alone and aid in increasing the diagnostic accuracy of CCTA to predict hemodynamically significant CAD determined by invasive FFR. The main results of Part II indicate that implantation of the BVS is feasible however no benefit with regard to myocardial perfusion is observed during hyperemia or cold pressor testing. These findings do not support the use of BVS instead of metallic DES, especially since large randomized trials have illustrated that there is an increased risk in scaffold thrombosis during the first three years. Still, long-term outcome (>3 years) has yet to become available. The results of the studies in Part III indicate that the vast majority of patients with a CTO have significantly impaired myocardial perfusion with great effect of successful CTO PCI on recovery of myocardial perfusion and decrease of ischemic burden. Patient selection for CTO PCI should be based on expected patient benefit rather than lesion complexity

IAEA Atlas of Cardiac PET/CT

This open access book presents a wide portfolio of examples of positron emission tomography coupled with computer tomography (PET/CT) studies in various cardiac conditions in order to provide a rationale for the implementation of this technology in an array of clinical conditions. Cardiovascular diseases are a major contributor to premature morbidity and mortality worldwide. Low- and middle-income countries (LMICs) are particularly affected by cardiovascular diseases (CVDs), with more than 75% of all CVDs deaths occurring in these countries. For this reason, target 3.4 of the United Nations (UN) Sustainable Development Goals (SDGs) agenda aims at a 30% reduction in premature mortality due to non-communicable diseases (NCDs), which include CVDs, by 2030. Among CVDs, ischemic heart disease (IHD) plays an important role and, according to the Institute for Health Metrics and Evaluation (IHME), it was responsible for 15.96% of global deaths in 2017. Between 2000 and 2017, the number of IHD deaths worldwide increased by 0.26% per year. Several imaging tools help to non-invasively diagnose, stratify risk and guide management in cardiac disease. They include nuclear cardiology techniques, using either SPECT (single photon emission computed tomography) or PET/CT. While myocardial imaging with SPECT has been fully embraced by the cardiology community and is widely available worldwide, PET/CT introduction has been slower, due not only to its higher costs, but also to the limited availability of PET/VCT scanners, mostly utilized for oncological applications. This book is an invaluable tool for nuclear medicine physicians, cardiologists and radiologists