CT Angiography

10,000.00

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.

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Description

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 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.[2] 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. This is because the test is highly sensitive (over 90% detection rate), so a negative test result largely rules out coronary artery disease (i.e. the test has a high negative predictive value).[3] The test is somewhat less specific, however, so a positive result is less conclusive and may need to be confirmed by subsequent invasive angiography.
The positive predictive value of cardiac CTA is approximately 82% and the negative predictive value is around 93%. This means for every 100 patients who appear to have coronary artery disease after CT angiography, 18 of them actually won’t have it, and that for every 100 patients who have a negative CT angio test result (i.e. the test says they do not have coronary artery disease), 7 will actually have the disease as defined by the reference standard of invasive coronary angiography via cardiac catheterization.[4] Both coronary CT angiography and invasive angiography via cardiac catheterization yield similar diagnostic accuracy when both are being compared to a third reference standard such as intravascular ultrasound or fractional flow reserve.
In addition to the diagnostic abilities, cardiac CTA beholds important prognostic information. Stenosis severity and extent of coronary artery disease are important prognostic indicators.[7] However, one of 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.