Wikipedia
A CT scan, also called X-ray computed tomography (X-ray CT) and computerized axial tomography scan (CAT scan), makes use of computer-processed combinations of many X-ray images 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.
Digital geometry processing is used to generate a three-dimensional image of the inside of the object from a large series of two-dimensional radiographic images taken around a single axis of rotation. Medical imaging is the most common application of X-ray CT. Its cross-sectional images are used for diagnostic and therapeutic purposes in various medical disciplines. The rest of this article discusses medical-imaging X-ray CT; industrial applications of X-ray CT are discussed at industrial computed tomography scanning.
As X-ray CT is the most common form of CT in medicine and various other contexts, the term computed tomography alone (or CT) is often used to refer to X-ray CT, although other types exist, such as positron emission tomography (PET) and single-photon emission computed tomography (SPECT). Older and less preferred terms that also refer to X-ray CT are computed axial tomography (CAT scan) and computer-aided/assisted tomography. X-ray CT is a form of radiography, although the word "radiography" used alone usually refers, by wide convention, to non-tomographic radiography.
CT produces a volume of data that can be manipulated in order to demonstrate various bodily structures based on their ability to block the X-ray beam. Although, historically, the images generated were in the axial or transverse plane, perpendicular to the long axis of the body, modern scanners allow this volume of data to be reformatted in various planes or even as volumetric (3D) representations of structures. Although most common in medicine, CT is also used in other fields, such as nondestructive materials testing. Another example is archaeological uses such as imaging the contents of sarcophagi. Individuals responsible for performing CT exams are called radiographers or radiologic technologists.
Use of CT has increased dramatically over the last two decades in many countries. An estimated 72 million scans were performed in the United States in 2007. One study estimated that as many as 0.4% of current cancers in the United States are due to CTs performed in the past and that this may increase to as high as 1.5 to 2% with 2007 rates of CT use; however, this estimate is disputed, as there is not a consensus about the existence of damage from low levels of radiation. Kidney problems may occasionally occur following intravenous contrast agents used in some types of studies.
Usage examples of "ct scan".
They drank cups of coffee and chatted, while I put on a hospital robe and had a chest X ray and then an abdominal-pelvic CT scan.
But the CT scan results should pinpoint the age even more accurately.
She silently thanked God that the ER doctor had ordered a CT scan rather than an MRI.
We always do a CT scan when there's a head injury, to check for evidence of bleeding.
Tyson was intubated immediately and the doctor ordered a CT scan as well as a head and spinal scan.
Watson ignores them, ignoring also the CT scan she has been admiring, with its textbook perfect depiction of a brain demolished by a bullet.
He feels as though he is being subjected to an electron-beam CT scan of such a sophisticated nature that it not only reveals the condition of his arteries and internal organs, but also maps his secrets and the true condition of his soul.
So I spent a worse pincushion and pill-popping afternoon with X-rays, CT scan and embarrassing interior searches, and wrote as requested a long list of where I'd been in the past two months.