FAQs

CT imaging is particularly useful because it can show several types of tissue—lung, bone, soft tissue and blood vessels—with great clarity. Using specialized equipment and expertise to create and interpret CT scans of the body, radiologists can more easily diagnose problems such as cancers, cardiovascular disease, infectious disease, trauma and musculoskeletal disorders.

What are some common uses of the procedure?
Because it provides detailed, cross-sectional views of all types of tissue, CT is one of the best tools for studying the chest and abdomen. It is often the preferred method for diagnosing many different cancers, including lung, liver and pancreatic cancer, since the image allows a physician to confirm the presence of a tumor and measure its size, precise location and the extent of the tumor's involvement with other nearby tissue. CT examinations are often used to plan and properly administer radiation treatments for tumors, to guide biopsies and other minimally invasive procedures and to plan surgery and determine surgical resectability. CT can clearly show even very small bones as well as surrounding tissues such as muscle and blood vessels. This makes it invaluable in diagnosing and treating spinal problems and injuries to the hands, feet and other skeletal structures. CT images can also be used to measure bone mineral density for the detection of osteoporosis. In cases of trauma CT can quickly identify injuries to the liver, spleen, kidneys or other internal organs. Many dedicated shock-trauma centers have a CT scanner in the emergency room. CT can also play a significant role in the detection, diagnosis and treatment of vascular diseases that can lead to stroke, kidney failure or even death.

What will I experience during the procedure?
CT scanning causes no pain, and with spiral CT the need to lie still for any length of time is reduced. For different parts of the body the patient preparation will be different. You may be asked to swallow either water or a positive contrast material, a liquid that allows the radiologist to better see the stomach, small bowel and colon. Some patients find the taste of the contrast material mildly unpleasant but most can easily tolerate it. Your exam may require the administration of the material by enema if the colon is the focus of the study. You will experience a sense of abdominal fullness and may feel an increasing need to expel the liquid. Be patient; the mild discomfort will not last long. A contrast material is commonly injected into a vein to better define the blood vessels and kidneys and to accentuate the appearance between normal and abnormal tissue in organs like the liver and spleen. Some people report feeling a flush of heat and sometimes a metallic taste in the back of the mouth. These sensations usually disappear within a minute or two. Some people experience a mild itching sensation. If it persists or is accompanied by hives (small bumps on the skin), the itch can be treated easily with medication. In very rare cases, a patient may become short of breath or experience swelling in the throat or other parts of the body. These can be indications of a more serious reaction to the contrast material that should be treated promptly, so tell the technologist immediately if you experience these symptoms. Fortunately, with the safety of the newest contrast materials, these adverse effects are very rare. You will be alone in the room during the scan; however, the technologist can see, hear and speak with you at all times.

What are the benefits vs. risks?

Benefits

• Unlike other imaging methods, CT scanning offers detailed views of many types of tissue including the lungs, bones, soft tissues and blood vessels.
• CT scanning is painless, noninvasive, and accurate.
• CT examinations are fast and simple. For example, in trauma cases they can reveal internal injuries and bleeding quickly enough to save lives.
• Diagnosis made with the assistance of CT can eliminate the need for invasive exploratory surgery and surgical biopsy.
• CT scanning can identify normal and abnormal structures, making it a useful tool to guide radiotherapy, needle biopsies and other minimally invasive procedures.
• CT has been shown to be a cost-effective imaging tool for a wide range of clinical problems.

Risks

• CT does involve exposure to radiation in the form of x-rays, but the benefit of an accurate diagnosis far outweighs the risk. The effective radiation dose from this procedure is about 10 mSv, which is about the same as the average person receives from background radiation in three years.
• Women should always inform their doctor or x-ray technologist if there is any possibility that they are pregnant.
• Nursing mothers should wait 24 hours after contrast injection before resuming breast feeding.
•  The risk of serious allergic reaction to iodine-containing contrast material is rare, and our radiology department is well equipped to deal with them.