CT scanning is a quick method of scanning that involves lying on a table which moves through a circular gantry with a rotating x-ray beam. These x-rays which are then picked up by an array of sensitive detectors on the gantry and the information converted by a high powered computer processor to give detailed images which can be reviewed and manipulated on a workstation.
Advantages of using CT
The scan itself takes only a matter of seconds. Depending on what part of the body is being scanned it may be necessary to drink an oral contrast agent (a fruit or aniseed flavoured drink over about an hour prior to the scan) to show the bowel or to have an intravenous contrast injection into an arm vein to show the blood vessels and internal organs in more detail.
CT scanning has improved dramatically in recent years with the advent of Multidetector CT (MDCT) which enables the radiologist to view scans in multiple planes and create complex 3D reconstructions that assist in planning interventional radiology procedures.
CT Angiograms enable the demonstration of arteries in a non-invasive manner and state of the art 64 slice multidetector CT scanners are fast enough to perform cardiac CT to demonstrate the heart and coronary arteries without interference from the heart beating.
CT scanning is sometimes used as a screening examination particularly for bowel cancer and heart disease for those with relevant risk factors.
Computed tomography uses a finely collimated X-ray beam to scan through the area of interest. Recent years have seen the development of multi-detector CT systems (MDCT – also known as multislice CT). Images can now be captured within a split-second, allowing for example, detailed pictures of the beating heart. The resolution has also increased in all directions allowing the most suitable plane of imaging to be chosen at the time of reporting, as well as allowing for 3-D image manipulation.