CT scans or CAT scans have been valuable for the diagnosis and treatment of diseases and injuries since the mid-1970’s. CT stands for computed tomography. These machines create detailed pictures in two and three dimensions of organs, bones and blood vessels inside the body.
CT scanning can be performed on almost any part of the body and is unique in that it can scan different types of tissues at the same time. It is often used to rapidly assess victims of trauma to quickly diagnose a variety of injuries from head to toe. It can also diagnose different types of cancer, heart disease and strokes, as well as view blood vessels. It can produce images of the head and brain to aid in the diagnosis and treatment of tumors, blood clots, or to view nerves and blood vessels. Because of the fine detail it produces, CT is also used extensively to image small body parts and structures.
Fluoroscopic CT is used in interventional procedures so the physician can see their progress as they insert needles into the body to biopsy organs or drain cysts/abscesses. This type of imaging enables the physician to provide a more minimally invasive treatment.
Computed tomography uses x-rays to produce images. As with traditional x-ray, different types of tissues absorb the x-rays at different levels. These variations allow images to be formed into pictures that have amazing clarity and detail. Instead of taking a picture from one position, however, the CT scanner has a large circular opening where the patient can lie down. Inside is a rotating frame with an x-ray tube and opposing detectors. Each rotation gathers another “slice” of information that varies from 1mm to 10mm in thickness. CT scanners produce digital images that are viewed on computer. The computer can “stack” the slices to create a complete image.
Newer multi-detector CT scanners use a constantly spinning head and many rows of detectors to produce greater detail in much less time. It is now possible to create three-dimensional pictures of the heart and its blood vessels in as little as 5 seconds. Consequently, CT coronary angiography is emerging as a new tool to assess coronary artery disease non-invasively, without a catheterization procedure.