A computed axial tomography (CAT) scan is a medical imaging method that uses many X-ray measurements taken from different angles to produce tomographic (cross-sectional) images of specific areas of the part of the body that was scanned. It allows for restructured images in various planes and even as three-dimensional (3D) or volumetric representation of body structures.
A CAT scan is one of the most accurate and fastest tools for examining the head, neck, chest, abdomen and pelvis. It is used to examine patients with trauma injuries as it identifies major injuries to the major internal organs. CAT scans are also used to evaluate vascular injuries such as stroke because it helps distinguish between ischemic and hemorrhagic strokes, each of which have dramatically different treatments.
One of the major advantages of a CAT scan is the ability to image soft tissue, blood vessels and bone. Unlike MRIs, CAT scans can be performed on patients with metal implants/medical devices. It can also be used to guide minimally invasive procedures (such as needle aspirations and needle biopsies of the lungs, abdomen, pelvis and bones) because it provides real-time imaging.
Since CAT scans are created by several X-ray measurements, it exposes the body to ionized radiation, and several studies have associated them with a slight increase in cancer risk. They are generally not recommended for pregnant women or children unless it is medically essential and when a CAT scan is taken, it should always be done with low-dose techniques.