Computed Tomography (CT) Procedures

Computed tomography, commonly known as CT or CAT scan, is a painless, non-invasive diagnostic tool that uses a specialized form of X-ray coupled with computer technology to produce cross-sectional images (slices) of soft tissue, organs, bone and blood vessels in any area of your body. CT has revolutionized medical imaging by providing more detailed information than conventional X-rays, making it possible to diagnose and manage certain diseases earlier and more accurately and, ultimately, to provide better care for patients.

Uses of CT

CT scans are used to check the size and structure of an organ or other soft tissue and to determine if it is infected, solid or filled with fluid. The scans are used to diagnose tumors, cancers, spinal injuries, heart disease, vascular conditions, brain disorders and various other abnormalities within the body. For example, when someone has abdominal pain, CT can help determine if the cause is acute appendicitis, bowel obstruction or kidney stones.

CT scans also are used to rapidly diagnose traumatic injuries and to guide a number of minimally invasive procedures, such as needle biopsies, catheter placement, fluid drainage and duct and vessel stenting.

How CT Works

CT uses X-rays to detect and record the radiation absorbed by different tissues. During a CT scan, an X-ray tube focuses a precise beam of energy on a section of the body. A computer analyzes the readings from the X-ray at thousands of different points and converts the information into images radiologists and other doctors use to analyze internal organs and tissue.

Safeness of CT Procedures

Although, there is no conclusive evidence that radiation from diagnostic X-rays causes cancer, some studies of large populations exposed to radiation from other sources have demonstrated slight increases in cancer risk. The estimated risk of cancer over a person's lifetime from a single CT scan has been estimated to be a fraction of this risk (0.03%-0.05%).

We are all exposed to small amounts of radiation from environmental sources such as soil, rocks, building materials, air, water and cosmic radiation. The estimated radiation from a single abdominal CT is comparable to the background radiation from environmental sources that you would be exposed to over a 20-month period. For more information about radiation, go to www.imagegently.org, www.acr.org or www.cancer.gov/cancertopics.

For exams requiring contrast dye (produces a clearer image), if you have had an allergic reaction to the contrast dye used in a prior CT study or have kidney disease, please let your doctor or our imaging staff know PRIOR to your CT exam. We can provide medication to prevent this rare event. The risk of a severe allergic reaction from the contrast dye is approximately one in 10,000 people.

If you are or think you may be pregnant, please discuss this with your doctor as pregnant women should undergo CT only if medically necessary. Usually, pregnant women can undergo alternative imaging tests such as sonography or magnetic resonance imaging instead. If you are breastfeeding and receive intravenous contrast dye for your exam, you should discard your milk for up to 24 hours following the exam before breastfeeding again. Please discuss any specific instructions about breastfeeding with your doctor or the imaging center staff. For more information, please visit www.radiologyinfo.org or www.acr.org.