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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 atherosclerotic plaques in the coronary arteries that can narrow arteries and increase the risk of heart attack. [1] These plaques are the cause of most heart ...
ICD-9-CM. 87.41. OPS-301 code. 3-224. [edit on Wikidata] Coronary CT angiography (CTA or CCTA) is the use of computed tomography (CT) angiography to assess the coronary arteries of the heart. The patient receives an intravenous injection of radiocontrast and then the heart is scanned using a high speed CT scanner, allowing physicians to assess ...
A physician may recommend cardiac imaging to support a diagnosis of a heart condition. Medical specialty professional organizations discourage the use of routine cardiac imaging during pre-operative assessment for patients about to undergo low or mid-risk non-cardiac surgery because the procedure carries risks and is unlikely to result in the change of a patient's management. [1]
Computed tomography angiography (also called CT angiography or CTA) is a computed tomography technique used for angiography —the visualization of arteries and veins —throughout the human body. Using contrast injected into the blood vessels, images are created to look for blockages, aneurysms (dilations of walls), dissections (tearing of ...
The risks of CT scan radiation are especially important in patients undergoing recurrent CT scans within a short time span of one to five years. [156] [157] [158] Some experts note that CT scans are known to be "overused," and "there is distressingly little evidence of better health outcomes associated with the current high rate of scans."
The Hounsfield unit (HU) scale is a linear transformation of the original linear attenuation coefficient measurement into one in which the radiodensity of distilled water at standard pressure and temperature (STP) is defined as 0 Hounsfield units (HU), while the radiodensity of air at STP is defined as −1000 HU.
Low-dose high-resolution (1.25 mm) chest CT. HRCT is performed using a conventional CT scanner. However, imaging parameters are chosen so as to maximize spatial resolution: [1] a narrow slice width is used (usually 1–2 mm), a high spatial resolution image reconstruction algorithm is used, field of view is minimized, so as to minimize the size of each pixel, and other scan factors (e.g. focal ...
The history of X-ray computed tomography (CT) dates back to at least 1917 with the mathematical theory of the Radon transform. [1][2] In the early 1900s an Italian radiologist named Alessandro Vallebona invented tomography (named "stratigrafia") which used radiographic film to see a single slice of the body. [3][4][5][6][7][8][9][10][11] It was ...