CT- Scan
What is a CT Scan?
Unlike conventional 2-dimensional x-ray scans (see Radiography) CT scans produce multiple 2-dimensional images to build up cross-sections of the body to create a 3-dimensional image. These images are more detailed and provide more information. They are particularly useful when investigating the size and location of a cancer tumour or breakages of bones in delicate areas. In emergencies a CT scan will reveal injuries and bleeding quickly so that the patient can be treated as necessary. [X5]
The patient lies still in a ring of x-ray beams as the x-ray tube rotates around the body. Signals are collected by the computer to form 2-D images, which are stacked to form a 3-D image. CT-scans typically last 10 to 20 minutes.
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The radiographer may give the patient a contrast medium to make the image clearer. This is often called a ‘Barium meal’; Barium has a high atomic number making it very ‘radiodense’. This absorbed more x-rays making structures clearer on the image. [X6]
Safety
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According to radiologyinfo.org, a typical low-dose CT chest scan delivers a dosage of 1.5mSv which is an equivalent banana dosage of 15000 bananas. Also, a typical CT scan of the spine delivers an equivalent banana radiation dosage of 60000 bananas. (Click on our banana scale page for more information) [X7]. Although this may seem like a relatively high dosage, the benefits of a CT scan in most situations will highly outweigh any associated risk.
Image Source (patient.info)