Comparison of calcium scores from thick– and thin image slice–computed tomography scanning in predicting future coronary events (original) (raw)
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2020
Worldwide the health expenditures as a percentage of each national gross domestic product continue to rise. Cardiovascular diseases as part of the noncommunicable disease group, according to the World Health Organization and the most important scientific associations, are growing due to the aging of the population and the increase of cardiovascular risk factors, due to the epidemiologic as well as to the health transition, especially in the developing countries, which account for the majority of the population in the world (Lopez et al., 2006). In the last few decades we witnessed a proliferation of diagnostic tests to evaluate cardiac heart diseases and in particular coronary artery disease (CAD): exercise stress test, transthoracic echocardiography, stress echocardiography, stress single photon emission computed tomography, myocardial perfusion imaging, magnetic resonance, fractional flow reserve, electron beam computed tomography. Each diagnostic test, which continuously evolves due to technological improvements, proved to have a high sensibility, specificity and good accuracy in identifying symptomatic as well asymptomatic CAD patients. All these tests are however unable to give us information about the anatomy of the coronary arteries, which is essential to provide a treatment that goes beyond the medical treatment and in particular when cardiac surgery is needed. In fact catheter angiography or invasive coronary angiography (ICA), since its introduction in the second half of last century, was the only test able to visualize, in vivo, the coronary tree and to provide images of the coronary artery anatomy upon which both cardiologists and surgeons decide if a patient should be revascularized or medically treated. With time ICA increased its performance due to the improvement in its software and hardware (quantitative coronary angiography, flat panel digital detectors), and due to the introduction of important tools which can be used routinely like intravascular coronary ultrasound, that for the first time visualized, in vivo, the presence of non calcified plaques and vessel's positive remodeling. There are other interesting tools that can be associated to ICA, but, for the moment, are the armamentarium of some specialized centers and mainly used for research purposes like elastography, spectroscopy, angioscopy, thermography and optical coherence thermography. www.intechopen.com Coronary Angiography-Advances in Noninvasive Imaging Approach for Evaluation of Coronary Artery Disease 200 All this data places ICA as the "reference" technique or "gold standard" technique to study the anatomy of coronary arteries. ICA has been widely employed to validate the results obtained with functional procedures, even though the anatomical findings of ICA are also judged by functional tests (Winchester et al., 2010). These interdependence of validation shows how a technique, even ICA, cannot be considered the unique "gold standard" technique to study CAD patients. In fact clinicians while studying their patients have to consider more than one question (diagnostic question, prognostic question, therapeutic question) and ICA alone is unable to give an exhaustive answer to all these questions (Mark et al., 2010). This is the reason why we are in search for technologies to evaluate CAD patients and in particular to study the anatomy of their coronary arteries keeping in mind that these new tests have to be feasible, able to compete with ICA in providing accurate information and, last but not least, economically affordable.
Diagnosing Heart Disease with Cardiac Computed Tomography
Computed tomography, commonly known as a CT scan, combines multiple X-ray images with the aid of a computer to produce cross-sectional views of the body. Cardiac CT is a heart-imaging test that uses CT technology with or without intravenous (IV) contrast (dye) to visualize the heart anatomy, coronary circulation, and great vessels (which includes the aorta, pulmonary veins, and arteries).
Atherosclerosis, 2015
Coronary artery calcium (CAC) scanning is a reliable, noninvasive technique for estimating overall coronary plaque burden and for identifying risk for future cardiac events. Arthur Agatston and Warren Janowitz published the first technique for scoring CAC scans in 1990. Given the lack of available data correlating CAC with burden of coronary atherosclerosis at that time, their scoring algorithm was remarkable, but somewhat arbitrary. Since then, a few other scoring techniques have been proposed for the measurement of CAC including the Volume score and Mass score. Yet despite new data, little in this field has changed in the last 15 years. The main focus of our paper is to review the implications of the current approach to scoring CAC scans in terms of correlation with the central disease e coronary atherosclerosis. We first discuss the methodology of each available scoring system, describing how each of these scores make important indirect assumptions in the way they account (or do not account) for calcium density, location of calcium, spatial distribution of calcium, and microcalcification/emerging calcium that might limit their predictive power. These assumptions require further study in welldesigned, large event-driven studies. In general, all of these scores are adequate and are highly correlated with each other. Despite its age, the Agatston score remains the most extensively studied and widely accepted technique in both the clinical and research settings. After discussing CAC scoring in the era of contrast enhanced coronary CT angiography, we discuss suggested potential modifications to current CAC scanning protocols with respect to tube voltage, tube current, and slice thickness which may further improve the value of CAC scoring. We close with a focused discussion of the most important future directions in the field of CAC scoring.
Impact of motion artefact on the measurement of coronary calcium score
The British Journal of Radiology, 2000
Reports have shown that total coronary calcium (CC) measured by electron beam CT (EBCT) correlates well with atheroma extent, and this in turn is a reliable indicator of risk for future ischaemic events. Although total CC may be measured using a conventional CT scanner, image quality is degraded by cardiac motion artefact. Errors in CC measurement owing to slice misregistration between adjacent breath-holds affect both conventional CT and EBCT. The latest generation conventional CT scanners have acquisition times of 500 ms or shorter, and, when combined with ECG triggering, quantitative CC measurement without reliance upon EBCT becomes a real possibility. We investigated the effect of motion on the measured calcium score using a moving phantom. Our results show that use of ECG triggering with conventional CT improves reproducibility of Agatston calcium score measurement. Increasing motion time during image acquisition results in an apparent increase in the Agatston CC score. Alternative measures of the amount of CC may be less susceptible to motion-induced bias, but have a similar reproducibility.
The Essentials of Cardiac Computerized Tomography
Cardiology and Therapy, 2015
Cardiac computerized tomography (CT) has evolved from a research tool to an important diagnostic investigation in cardiology, and is now recommended in European, US, and UK guidelines. This review is designed to give the reader an overview of the current state of cardiac CT. The role of cardiac CT is multifaceted, and includes risk stratification, disease detection, coronary plaque quantification, defining congenital heart disease, planning for structural intervention, and, more recently, assessment of ischemia. This paper addresses basic principles as well as newer evidence.
Journal of Cardiovascular Computed Tomography, 2010
The American College of Cardiology Foundation (ACCF), along with key specialty and subspecialty societies, conducted an appropriate use review of common clinical scenarios where cardiac computed tomography (CCT) is frequently considered. The present document is an update to the original CCT/cardiac magnetic resonance (CMR) appropriateness criteria published in 2006, written to reflect changes in test utilization, to incorporate new clinical data, and to clarify CCT use where omissions or lack of clarity existed in the original criteria (1). The indications for this review were drawn from common applications or anticipated uses, as well as from current clinical practice guidelines. Ninety-three clinical scenarios were developed by a writing group and scored by a separate technical panel on a scale of 1 to 9 to designate appropriate use, inappropriate use, or uncertain use. In general, use of CCT angiography for diagnosis and risk assessment in patients with low or intermediate risk or pretest probability for coronary artery disease (CAD) was viewed favorably, whereas testing in high-risk patients, routine repeat testing, and general screening in certain clinical scenarios were viewed less favorably. Use of noncontrast computed tomography (CT) for calcium scoring was rated as appropriate within intermediate- and selected low-risk patients. Appropriate applications of CCT are also within the category of cardiac structural and functional evaluation. It is anticipated that these results will have an impact on physician decision making, performance, and reimbursement policy, and that they will help guide future research.