CT scan health tips by |vradvise.com|

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CT scan

A CT scan,^[1] also known as computed tomography scan, and formerly known as a computerized axial tomography scan or CAT scan,^[3] makes use of computer-processed combinations of many X-ray measurements taken from different angles to produce cross-sectional (tomographic) images (virtual "slices") of specific areas of a scanned object, allowing the user to see inside the object without cutting.

Medical useEdit

Since its introduction in the 1970s, CT has become an important tool in medical imaging to supplement X-rays and medical ultrasonography. It has more recently been used for preventive medicine or screening for disease, for example CT colonography for people with a high risk of colon cancer, or full-motion heart scans for people with high risk of heart disease. A number of institutions offer full-body scans for the general population although this practice goes against the advice and official position of many professional organizations in the field primarily due to the radiation dose applied.^[15]

Ed

Angiography

Computed tomography angiography (CTA) is contrast CT to visualize arterial and venousvessels throughout the body. This ranges from arteries serving the brain to those bringing blood to the lungs, kidneys, arms and legs. An example of this type of exam is CT pulmonary angiogram(CTPA) used to diagnose pulmonary embolism(PE). It employs computed tomography and an iodine based contrast agent to obtain an image of the pulmonary arteries.

CardiacEdit

A CT scan of the heart is performed to gain knowledge about cardiac or coronary anatomy.^[28]Traditionally, cardiac CT scans are used to detect, diagnose or follow up coronary artery disease.^[29]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.^[30][31][32]

The main forms of cardiac CT scanning are:

• Coronary CT angiography (CTA): the use of CT 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 radiologists to assess the extent of occlusion in the coronary arteries, usually in order to diagnose coronary artery disease.
• Coronary CT calcium scan: also used 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.^[33]A typical coronary CT calcium scan is done without the use of radiocontrast, but it can possibly be done from contrast-enhanced images as well.^[34]

To better visualize the anatomy, post-processing of the images is common.^[29] Most common are multiplanar reconstructions (MPR) and volume rendering. For more complex anatomies and procedures, such as heart valve interventions, a true 3D reconstruction or a 3D print is created based on these CT images to gain a deeper understanding.