X-ray Vision: Diagnostic X-rays and CT Scans
Suzanne Amador Kane, Boris A. Gelman in Introduction to Physics in Modern Medicine, 2020
Although less commonly used, electron beam computed tomography is another method for performing fast CT scans. Rather than having a rotating x-ray source and detectors, these scanners have a ring of fixed detectors and a separate ring of tungsten x-ray targets. An electron beam is then rapidly steered around the tungsten ring, creating beams of x-rays wherever it hits. Because only the x-ray source's electron beam is moved, the scan can take place much more quickly. This can reduce complete spiral scan times to a twentieth of a second. Ultrafast spiral CT scanners have particular utility for imaging the beating heart, imaging the lungs, and studying cardiovascular diseases.
Cardiac CT and MRI: State of the Art
Phillip M. Boiselle, Charles S. White in New Techniques in Cardiothoracic Imaging, 2007
Most initial work with noninvasive coronary assessment was performed with electron beam tomography (EBT). Developed in the early 1980s, the EBT configuration has no moving parts and thus permits temporal resolution of approximately 100 ms (1). EBT has proved valuable in the evaluation of coronary calcium burden, but its inferior spatial resolution and moderate image noise have prevented its widespread adoption for detailed delineation of the coronary arteries.
Coronary heart disease in women
Clive Handler, Gerry Coghlan, Nick Brown in Management of Cardiac Problems in Primary Care, 2018
There are insufficient data comparing the diagnostic and prognostic value of electron beam computed tomography in men and women. The technique is experimental, expensive, not available on the NHS, and adds no useful or incremental information to conventional clinical risk estimations.
Subclinical macroangiopathic target organ damage in type 1 diabetes mellitus patients
Published in Blood Pressure, 2020
Magdalena Błaszkowska, Anna Shalimova, Bogumił Wolnik, Elżbieta Orłowska-Kunikowska, Beata Graff, Michał Hoffmann, Peter Nilsson, Jacek Wolf, Krzysztof Narkiewicz
CAC can be detected and quantified using electron beam computed tomography. It is a non-contrast procedure, where contiguous 3-mm CT images are acquired at 100-ms exposure. The scanning area is from the bifurcation of the main pulmonary artery to the diaphragm, in the supine position with the breath held for 35–45 s. Images are electrocardiographically triggered at 80% of RR interval. Areas of calcification are defined by a minimum area of 3 contiguous pixels with an attenuation minimum of 130 Hounsfield Units (HU). The CAC score can be obtained using the standard Agatston method – separately for each region by multiplying the area by the density score (1 for 130–199 HU, 2 for 200–299 HU, 3 for 300–399 HU, 4 for >399 HU). The total CAC score is calculated by adding the scores for all slices separately for the left main, left anterior descending, circumflex and right coronary arteries (Figure 2). The total radiation dose is about 1–1.5 mSV [47].
Predictors of long-term absence of coronary artery calcium in individuals with high blood pressure: results from the MESA study
Published in Annals of Medicine, 2023
Si You, Jing-Wei Gao, Hai-Feng Zhang, Zhuo-Chao Xiong, Qing-Yun Hao, Jia-Jin Han, Jing-Feng Wang, Shao-Ling Zhang, Pin-Ming Liu
Depending on the study site, the MESA used either a multi-detector computed tomography or a cardiac-gated electron-beam computed tomography to assess CAC, which has been shown to be comparable [21]. All MESA participants underwent a CAC scan at Exam 1 (2000–2002), but only 50% of them repeated a CAC scan at Exam 5 (2010–2011). The severity of each calcified lesion was evaluated independently by 2 blinded analysts using the Agatston method, and the scores were summed across all lesions in all coronary artery branches (left main, left anterior descending, circumflex, and right coronary) [21,22]. In this study, long-term CAC = 0 was defined as maintaining CAC = 0 at baseline and at Exam 5. Incident CAC was defined as CAC > 0 at Exam 5 in participants who had CAC = 0 at baseline.
Candidate-gene association analysis for a continuous phenotype with a spike at zero using parent-offspring trios
Published in Journal of Applied Statistics, 2020
Nadja Klein, Andrew Entwistle, Albert Rosenberger, Thomas Kneib, Heike Bickeböller
Besides normally distributed traits or traits that can be easily transformed to a normal distribution (such as blood concentrations by a logarithmic transformation), TDT versions have been developed for the extreme tails of normally distributed traits [2], and for survival traits such as age of disease onset [15]. This article focusses on a non-negative continuous phenotype with a probability mass at zero and a continuous distribution for values greater than zero, such as the measurement of coronary artery calcification (CAC) by electron beam computed tomography [22]. This tomography accurately measures CAC at the region of the artery that is investigated.
Related Knowledge Centers
- Angiography
- Ionizing Radiation
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- Artery
- CT Scan
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- X-Ray
- Coronary Arteries
- Signal-to-Noise Ratio