Computed tomography (CT), or CAT scan, is a sophisticated x-ray imaging system that scans thin “slices” of the body on all sides, then combines those slices into a highly detailed, three-dimensional digital image of hard and soft tissues in the body. The procedure is non-invasive, requires minimal radiation exposure and can simultaneously depict tissues of different densities, which is not possible with traditional x-ray methods.
CT scans are highly useful for detecting problems, examining injury, guiding biopsy needles and aiding in surgical preparation of almost all parts of the body. CT is able to detect tumors, cancer, stroke, cardiovascular disease, musculoskeletal disorders, spine problems, arthritis, osteoporosis, problems in the lower gastrointestinal (GI) tract, colon, rectum and injuries to the brain, heart, liver, spleen, appendix, or other internal organs.
The patient is positioned on the table on his or her back, side or stomach, and may be provided with pillows for comfortable support. The technician leaves the room and the table moves slowly, often undetectably, through the CT scanner “doughnut.” The x-ray beam inside the CT unit spirals slowly around the patient on all sides, creating 360-degree images or slices of the area being examined; as the table and the patient move through the unit, many slices are captured. After the scan is complete, these slices are combined by computer into a highly detailed three-dimensional image of the injury. Depending on the size of the area being scanned, the examination can take five minutes or half an hour.
Most patients find the most uncomfortable aspect of CT scanning to be the need to lie still, but even this is reduced with spiral CT technology. If a contrast material is needed for better scan results, there may be some discomfort associated with its introduction (either by swallowing, injection or enema, depending on the area being studied).