A computerized tomography (CT scan) is a form of computer-assisted imaging, that is assembled from many x-rays. CT Scans are also known as CAT scans.
CT scans allow doctors and researchers to get detailed, highly accurate, 3D imaging of a body with depth into solid mass. This allows the inside of patients to be visually diagnosed without physical entry into the body. CT scans are used in diagnosing and analysis of: internal injuries, cancer, other tumors, blood clots or excess fluid and issues in the heart, liver, lungs, bones and joints.
The scans done by CT create layered images like stacked slices into the body. To produce the images, x-rays are taken from many angles, as the patient lays on a table in the middle of a circular opening, which is called a gantry. The computer then interprets the images and assembles them into a 3D image made out of 2D slices of the area being scanned. As x-rays don’t show soft tissues well, contrast materials -- such as iodine or barium sulfate -- may be injected. These contrast materials may be consumed orally or administered by enema, depending on what is being scanned for and where.
Cautions around CT scans
In general, CT scans are relatively safe when used sparingly. Though patients may not receive wounds that are associated with exploratory surgery, CT scans expose patients to low doses of ionizing radiation. This is the reason CT scans are best used sparingly, as ionizing radiation can cause cellular mutations and cancer. Risks increase with increased exposure to radiation. Also, specific types of CT scans are not recommended during pregnancy.
In addition, contrast materials may cause allergic reactions, interactions with some drugs and in some cases, kidney issues.
CT scans vs. MRIs
CT scans and MRIs use different types of machines for different purposes. MRI stands for magnetic resonance imaging, and it is a method for creating images of the interiors of objects, typically humans. MRIs employ radio-frequency (RF) waves and magnetic fields to excite atoms in the evaluated object. The patterns that appear are observed on a display. MRIs can provide real-time, three-dimensional views of body organs, muscles, and joints. The use of an MRI as a procedure is considered indispensable by many physicians, especially for the evaluation of injuries and the diagnosis and conditions of chronic diseases. MRIs can be used to reveal minor damage to tendons, ligaments, and muscles, as well as provide early warnings of advancing coronary disease, and can locate cancerous tumors.
MRIs do not use radiation as CT scans do, but are typically more expensive and also have safety issues considering the use of strong magnets. While CT scans are typically quick, MRIs take longer and are louder. However, MRIs can provide more detailed information regarding inner organs and soft tissues than a CT scan.
Here is a quick description of how CT scans work