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Computed Tomography

CT/CAT Scans

ct scans

CT scans: what are they?

CT (also known as “CAT”) stands for Computed Tomography. This procedure painlessly and rapidly creates detailed images of the body using X-rays in a specialized machine in which the X-ray tube rotates around the body. A computer is used to figure out the sum of X-ray shadows that its detector “sees” on its rotations, and is able to create very detailed cross-sectional images of any part of the body.

What are the advantages of CT scans?

CT scans are fast and non-invasive. They provide much more detailed information than X-rays since they examine the body from all angles and multiple slices are obtained through the region being imaged. Bones, as well as soft tissue organs and blood vessels alike, are well visualized.

What are the risks of CT scans?

CT uses X-rays, a form of ionizing radiation, to obtain images. Our highly-trained technologists take special care to ensure maximum safety. Additionally, the CT scanners have built-in safety systems to keep the exposure to a minimum. TRG and the Providence hospitals where the scanners are located are committed to the ALARA principle, which states that the radiation dose will be “As Low As Reasonably Achievable” to obtain a diagnostic quality study.

What can I expect?

During your procedure, you will be asked to lie on a table that will move you through a donut-shaped scanner. Your technologist will give you specific instructions so that you don’t move or breathe during the scanning time. While you are being scanned, you may hear a whirring sound, which is the scanner moving quickly around your body. You may feel the table move to correctly position the body. Some CT scans require an intravenous injection of a contrast agent (“dye”) to differentiate vessels and various organs. The contrast agents used are safe for most patients; your technologist will take a detailed allergy inventory prior to your injection to make sure that you are not predisposed to an allergic reaction to the contrast. If you have had a reaction with a previous contrast injection, be sure to communicate that with the technologist. Most CT procedures take less than 30 minutes to complete. Once your scan is complete, you will be able to return to your normal activities.

How should I prepare?

Some CT procedures require that you not eat or drink prior to your examination. You can continue your prescribed medications unless you have been instructed otherwise. If you have diabetes, you may need to delay your medication until you can resume eating. If you take Glucophage or Glucovance to regulate your diabetes, you will need to discontinue your medication 48 hours prior to the study. If this is concerning, we encourage you to speak with your physician. Your procedure may require that you change into an exam gown and remove glasses, dentures, hearing aids, and other items that may impede the view.

CT scans can be
performed at all sites.

CT Angiography

What is angiography?

Angiograms visualize blood vessels. There are many reasons why your doctor may feel an angiogram including whether you have pain in the legs when walking, diseases of the brain (including stroke and stroke precursors), high blood pressure, tumors, congenital abnormalities of blood vessels, and many others. With advancements in CT (Computed Tomography), radiologists can now perform angiograms with minimal downtime and as a same-day procedure.

What should I expect?

The CT angiogram usually takes about 20 minutes and involves an IV injection in the arm. You can go home immediately after the procedure. The only risk associated with this procedure is an allergic reaction to the contrast or infection at the IV site, but it is very rare.

How should I prepare?

Before some exams, you’ll be asked to not eat or drink for a period of time. Prescribed medications should be continued. Diabetic patients may need to delay their medication until after they have eaten in order to avoid an insulin reaction. You may wear a hospital gown and may have to remove anything which interferes with X-rays such as glasses, jewelry, dentures, hearing aids, etc. Women should always inform their CT technologist if there is any possibility of pregnancy.

How do I get the results?

After your study is over, the images will be evaluated by one of our radiologists with expertise in CT angiography imaging. A final report will be sent to your doctor who can then discuss the results with you in detail.

CT angiography can be
performed at:

Providence St. Vincent Medical Center

Providence Newberg Medical Center

Providence Seaside Diagnostic Imaging


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