Computed Tomography (CT), also called CAT scan, is a type of diagnostic test that combines x-rays and computer technology to provide views of soft tissue, bones and blood vessels. The technology creates sectional images, or “slices,” of the organs, tissues or vessels under evaluation.
What is CT used for?
Nearly every part of the body can be viewed with CT. CAT scan technology is frequently used to obtain a two-dimensional view of a cross section of the brain and other internal organs, such as the liver, lungs and spine. CT technology is valuable in detecting tumors, bleeding, and other abnormalities that may not show up on an ordinary x-ray. Nearly one-third of all emergency department patients undergo a CT procedure.
What types of illnesses or injuries will a CT procedure detect?
CT can help diagnose head and spine injuries, lung and liver disease, cancer, tumors, blood clots, internal bleeding and a host of other diseases and injuries. The test is often used when fast diagnosis is critical – it can be lifesaving for auto accident victims and other emergency department patients.
How does CT differ from other diagnostic tests?
Unlike other imaging techniques, such as x-ray and MRI, CT has the ability to image a combination of soft tissue, bone and blood vessels. This capability proves very useful in evaluating the chest and the abdomen, making the modality a preferred method for diagnosing cancers such as lung, liver and pancreatic among others. Advanced CT systems also are being used extensively in detecting heart disease and other vascular conditions.
What preparation is required before the CT scan?
Depending on the type of study, you may also receive a contrast medium. This is a dye that increases the quality of the CT images. The contrast medium may be administered orally, or by injection, or both. Some patients report a warm feeling or an unusual taste in their mouth from the contrast medium.
For abdominal and/or pelvic CT exam – have nothing to eat or drink for the 4 hours prior to your exam. Also, you will need to drink an oral contrast mixture before arriving for your appointment. If this mixture is not available at your doctor’s office, you may pick it up at our office. This mixture makes certain internal structures easier to see during the exam. Any medication prescribed by your physician should be taken as directed.
For some CT exams, contrast may have to be injected into your veins (IV contrast). Many exams do not require any contrast at all.
Should I tell the technologist about my medical history?
Yes. Before you are given an IV contrast, be sure to tell the technologist if you have allergies, asthma, heart problems, diabetes, or kidney problems; if you think you might be pregnant; or if you are currently undergoing any radiation therapy.