Claim: Study: CT scans rule out heart attacks faster
Verdict: SUPPORTS

Retrieved passages:
title: Coronary CT angiography
text: arrhythmias, coronary artery stents and tachycardia may result in a reduced image quality. With the advent of subsecond rotation combined with multi-slice CT (up to 320 slices), high resolution and high speed can be obtained at the same time, allowing excellent imaging of the coronary arteries (cardiac CT angiography). Images with even higher temporal resolution can be obtained using multi-cycle (also called multi-segmental) image reconstruction. In this technique, a portion of the heart is imaged during one heart cycle while an ECG trace is recorded. During the next heart cycle, the next portion of the heart is scanned for up

title: Electron beam tomography
text: structures, such as arteries, move several times their diameter during each heartbeat. Rapid imaging is therefore important to prevent blurring of moving structures during the scan. EBT detection of calcium deposits is accurate, fast and involves lower exposure to ionising radiation than conventional CT. Patients are exposed to radiation for a shorter period as it is faster in creating multiple images of the heart. The most advanced current commercial designs can perform image sweeps in as little as 0.025 seconds. By comparison, the fastest mechanically swept X-ray tube designs require about 0.25 seconds to perform an image sweep. For reference,

title: Vulnerable plaque
text: performed clinically with the goal of predicting susceptibility to future heart attack. In contrast to conventional angiography, cardiac CT angiography does enable visualization of the vessel wall as well as plaque composition. Some of the CT derived plaque characteristics can help predict for acute coronary syndrome. In addition, because these lesions do not produce significant stenoses, they are typically not considered "critical" and/or interventionable by interventional cardiologists, even though research indicates that they are the more important lesions for producing heart attacks. The tests most commonly performed clinically with the goal of testing susceptibility to future heart attack include several

title: Coronary CT angiography
text: a number of clinical settings. The faster capability has allowed the imaging of the heart with minimal involuntary motion, which creates motion blur on the image, and has a number of practical applications. It may be useful in the diagnosis of suspected coronary heart disease, for follow-up of a coronary artery bypass, for the evaluation of valvular heart disease and for the evaluation of cardiac masses. It is uncertain whether this modality will replace invasive coronary catheterization. At present, it appears that the greatest utility of cardiac CT lies in ruling out coronary artery disease rather than ruling it in.

title: Angiography
text: be clearly determined. Coronary angiography can visualize coronary artery stenosis, or narrowing of the blood vessel. The degree of stenosis can be determined by comparing the width of the lumen of narrowed segments of blood vessel with wider segments of adjacent vessel. To detect coronary artery disease, a CT scan is more satisfactory than an MRI scan. The sensitivity and specificity between CT and MRI were (97.2 percent and 87.4 percent) and (87.1 percent and 70.3 percent), respectively. Therefore, CT (mainly multislice CT) is more accepted, more widely available, more favored by patients, and more economic. Moreover, CT requires shorter

title: Coronary CT angiography
text: half a rotation, thus reducing motion blurring at high heart rates and potentially allowing for shorter breath-hold time. This is particularly useful for ill patients having difficulty holding their breath or unable to take heart-rate lowering medication. The speed advantages of 64-slice MSCT have rapidly established it as the minimum standard for newly installed CT scanners intended for cardiac scanning. Manufacturers have developed 320-slice and true 'volumetric' scanners, primarily for their improved cardiac scanning performance. Introduction of a CT scanner with a 160 mm detector in 2014 allows for imaging of the whole heart in a single beat without motion

title: Myocardial infarction
text: an ultrasound scan of the heart, is able to visualize the heart, its size, shape, and any abnormal motion of the heart walls as they beat that may indicate a myocardial infarction. The flow of blood can be imaged, and contrast dyes may be given to improve image. Other scans using radioactive contrast include SPECT CT-scans using thallium, sestamibi (MIBI scans) or tetrofosmin; or a PET scan using Fludeoxyglucose or rubidium-82. These nuclear medicine scans can visualize the perfusion of heart muscle. SPECT may also be used to determine viability of tissue, and whether areas of ischemia are inducible. Medical

title: Cardiac imaging
text: anesthesia and in a non-invasive way. A coronary CT calcium scan is a computed tomography (CT) scan of the heart for the assessment of severity of coronary artery disease. Specifically, it looks for calcium deposits in the coronary arteries that can narrow arteries and increase the risk of heart attack. This severity can be presented as Agatston score or Coronary Artery Calcium (CAC) score. The CAC score is an independent marker of risk for cardiac events, cardiac mortality, and all-cause mortality. In addition, it provides additional prognostic information to other cardiovascular risk markers. A typical coronary CT calcium scan is

title: Cardiomegaly
text: works during physical activity. 5. Cardiac computerized tomography (CT) or magnetic resonance imaging (MRI). In a cardiac CT scan, one lies on a table inside a machine called a gantry. An X-ray tube inside the machine rotates around the body and collects images of the heart and chest. 6. Blood tests: Blood tests may be ordered to check the levels of substances in the blood that may show a heart problem. Blood tests can also help rule out other conditions that may cause one's symptoms. 7. Cardiac catheterization and biopsy: In this procedure, a thin tube (catheter) is inserted in

title: Coronary CT angiography
text: to 5 total cycles until the entire heart is imaged. The reconstruction algorithm then combines the images from these different cycles to generate one complete image. The advantage of this method is that each image segment is acquired in less time as compared to acquiring the entire heart in one heart cycle, thus improving temporal resolution. The disadvantages are 1) the potential for image artifacts from fusing the image segments and 2) the requirement of additional X-ray radiation for image acquisition. Dual Source CT scanners, introduced in 2005, allow higher temporal resolution by acquiring a full CT slice in only

title: CT scan
text: of the heart is performed to gain knowledge about cardiac or coronary anatomy. Traditionally, cardiac CT scans are used to detect, diagnose or follow up coronary artery disease. More recently CT has played a key role in the fast evolving field of transcatheter structural heart interventions, more specifically in the transcatheter repair and replacement of heart valves. The main forms of cardiac CT scanning are: To better visualize the anatomy, post-processing of the images is common. Most common are multiplanar reconstructions (MPR) and volume rendering. For more complex anatomies and procedures, such as heart valve interventions, a true 3D reconstruction

title: Elliot McVeigh
text: and clinicians to develop low dose CT imaging and MR imaging techniques that will identify those people at substantially higher risk for heart attacks. Elliot McVeigh Elliot R. McVeigh is a Professor of Bioengineering, Medicine and Radiology at the University of California, San Diego (UCSD). His research utilises low dose CT imaging and MR imaging techniques to identify those people at substantially higher risk for heart attacks. McVeigh earned a BSc in physics in 1984 and a PhD in medical biophysics in 1988 at the University of Toronto. In 2007 he returned to Johns Hopkins to become the director of

title: Coronary CT angiography
text: Coronary CT angiography Coronary CT angiography (CTA) is the use of computed tomography (CT) angiography to assess the coronary arteries of the heart. The subject receives an intravenous injection of radiocontrast and then the heart is scanned using a high speed CT scanner, allowing physicians to assess the extent of occlusion in the coronary arteries, usually in order to diagnose coronary artery disease. CTA is superior to coronary CT calcium scan in determining the risk of Major Adverse Cardiac Events (MACE). Faster CT machines, due to multidetector capabilities, have made imaging of the heart and circulatory system very practical in

title: Coronary CT calcium scan
text: Coronary CT calcium scan A coronary CT calcium scan is a computed tomography (CT) scan of the heart for the assessment of severity of coronary artery disease. Specifically, it looks for calcium deposits in the coronary arteries that can narrow arteries and increase the risk of heart attack. This severity can be presented as Agatston score or coronary artery calcium (CAC) score. The CAC score is an independent marker of risk for cardiac events, cardiac mortality, and all-cause mortality. In addition, it provides additional prognostic information to other cardiovascular risk markers. A typical coronary CT calcium scan is done without

title: Coronary CT angiography
text: the unique features of cardiac CTA is the fact that it enables the visualization of the vessel wall, in a non-invasive manner. Therefore, the technique is able to identify characteristics of coronary artery disease that are associated to the development of acute coronary syndrome. Because the heart is effectively imaged more than once (described above), cardiac CT angiography can result in a relatively high radiation exposure (around 12 millisievert), although newer acquisition protocols, have recently been developed which drastically reduce this exposure to around 1 mSv (cfr. Pavone, Fioranelli, Dowe: Computed Tomography or Coronary Arteries, Springer 2009). By comparison, a

title: Major trauma
text: agent, but not oral administration. There are concerns that intravenous contrast administration in trauma situations without confirming adequate renal function may cause damage to kidneys, but this does not appear to be significant. In the U.S., CT or MRI scans are performed on 15% of those with trauma in emergency departments. Where blood pressure is low or the heart rate is increasedlikely from bleeding in the abdomenimmediate surgery bypassing a CT scan is recommended. Modern 64-slice CT scans are able to rule out with a high degree of accuracy, significant injuries to the neck following blunt trauma. Surgical techniques, using

title: Cardiac magnetic resonance imaging perfusion
text: stored as video files and are analysed on a dedicated workstation. The majority of clinical scans are analysed qualitatively by visually comparing the stress and rest scans in parallel. In a normal scan, the wash in (1st pass) of gadolinium into the myocardium can be seen as the myocardium turning from black to mid grey uniformly throughout the whole of the left ventricle in both the stress and rest scans. In an abnormal scan an area of the myocardium will turn grey slower than the surrounding tissue as the blood (and hence gadolinium) enters more slowly due to a narrowing

title: National Lung Screening Trial
text: people in the CT scan group had died from lung cancer, versus 442 people in the X-ray group; in other words, deaths in the CT scan group of patients were 20.3% lower than in the X-ray group. The study's review board concluded that this difference was statistically significant and recommended terminating the study. The director of the National Cancer Institute's director, Harold Varmus, said that early analysis results appeared to indicate that CT scans detected more lung cancers, at an earlier and more treatable stage, and that CT scans could therefore reduce the number of deaths in patients at high

title: BaleDoneen Method
text: if patients have plaque in their arteries since heart attacks and strokes can only occur in people with this disease. A 2015 study of more than 5,000 adults, published in Journal of the American College of Cardiology found that most initial cardiac events do not occur in patients considered at “high risk” based on risk factor scores. The study also stated that the accuracy of cardiovascular risk prediction was “significantly improved” if vascular imaging, such as ultrasound imaging or Coronary Artery Calcium score (CAC), was used. During the initial evaluation, and to monitor response to treatment with the BaleDoneen Method,

title: Incidental imaging finding
text: 1 in every 3 cardiac MRIs undercover an incidental finding. The same estimate is true for chest CTs (~30% prevalence of incidental findings). As the use of medical imaging, particularly CT and MRI studies, increases, the chance of detecting incidental findings is expected to increase. Incidental adrenal masses on imaging are common (0.6 to 1.3% of all abdominal CT). Differential diagnosis include adenoma, myelolipoma, cyst, lipoma, pheochromocytoma, adrenal cancer, metastatic cancer, hyperplasia, and tuberculosis. Some of these lesions are easily identified by radiographic appearance; however, it is often adenoma vs. cancer/metastasis that is most difficult to distinguish. Thus, clinical guidelines