CT Scan
A CT Scan (Computerized Tomography) combines several x-ray imagines obtained from different angels around your body. It then uses the images and computer processing to create cross-section images or slices of the bones, blood vessels and soft tissues in your body. They provide more detailed information than a plain X-ray can. It has many functions but one of the main functions it serves is to quickly diagnose trauma to the body as it can be used to visualize mostly every part of the body.
It is used to diagnose internal injuries and bleeding, muscle and bone disorders, location of tumor, blood clot or infection, to help guide procedures in surgery or radiation therapy. It’s also used to monitor diseases that is already been detected such as cancer, heart disease, lung and liver growths and measure effectiveness of treatment.
Safety
- As the CT collects more information, it carries a slightly higher risk of radiation exposure than X-ray though benefits still outweighs risk. At much levels, it may increase your risk for cancer slightly.
- Although there is no known risk to unborn children in pregnant mothers, notify your doctor if you may be pregnant as they will likely offer alternatives to imaging such as ultrasound or MRI which are safer.
- You may be asked to take contrast via, rectally or IV. Dyes can commonly cause site reactions of itchiness and redness but rarely can cause life threatening allergies as well. Notify your doctor if you have ever had a reaction.
How to Prepare
- You may be asked to remove clothing, jewelry and metallic objects.
- You may be asked to refrain from consuming food or drink a few hours before the testing.
- If you need contrast material, it can be administrated three ways:
- ORAL – If you are having a scan of your stomach or esophagus, you may need to swallow a liquid that tastes unpleasant.
- Intravenous – If you are having a gallbladder, urinary tract, liver, digestive or blood vessels scan, you may require IV contrast which will be injected through a vein in your arm. You may experience a flushed feeling or metallic taste in your mouth.
- Rectal – If you require an image of your intestines or rectum, you may need a contrast enema which make you feel bloated and uncomfortable.
What to Expect
- The test typically takes about 30 minutes from start to finish and can be done in a hospital or outpatient setting. It is painless.
- The scanner itself is large and shaped like a standing donut. You lay on a board and it drives you into a hole of the scanner. The machine moves around you while you lay flat. If a scan of your head is being done, an apparatus may be in there to hold your head in place. The X-ray tube and detectors rotate around you obtaining images in slices of your body part. A technologists in a separate room can hear and see you and may instruct you to hold your breath.
- After the exam you may proceed with activities as normal. If you’ve been given contrast you may be given special instructions and to drink plenty of fluid to filter out the material quickly. Images are sent to a radiologist for interpretation and results sent back to your doctor to discuss with you.
CT Scan – Mayo Clinic https://www.mayoclinic.org/tests-procedures/ct-scan/about/pac-20393675 Accessed January 28, 2019.
CT Scan – Medline Plus https://medlineplus.gov/ctscans.html Accessed January 28, 2019.
CTA Carotid
A Computerized Tomography (CTA) of the Carotid Arteries is commonly done at ECMC. This test may be ordered by your doctor to evaluate more precisely the extent of stenosis there may be in one or more of the arteries to help guide treatment decision making. This may compromise blood flow to your brain and/or cause occlusions leading to strokes or mini-strokes.
Safety
- No direct data suggests CT scan exposure links to cancer. There are some risks associated with radiation therefore the benefit must outweigh the risk.
- This test should be avoided in pregnant women.
- Diabetic precautions: If you are insulin-dependent diabetic, please remember to take your insulin as prescribed and compensate by drinking a fruit drink, etc. for the fasting you will be doing 2-3 hours prior to the test. Patients taking diabetic medications should take their dose as normal on the day of the test but stop for 48 hours after the test is done otherwise directed by your physician.
What to Expect
- Arrive 1 hour early for the test, do not eat for two hours prior to the test, drinking fluids is encouraged.
- Wear comfortable clothing and remove jewelry.
- You will lie into the CT scanner as directed by the technician. This is not completely enclosed like an MRI machine. The scanners rotate around you taking several pictures at different angles of your body getting slices that ultimately are compiled and delivered into two dimensional images on the technician’s computer.
- You will be injected of dye in IV form to highlight your vessels in the neck. The test takes a total of about 15 minutes.
- If you have heart or kidney conditions, diabetes, or some other condition requiring a serum creatinine check, you may be asked to give blood prior to the test to make sure your kidneys will be able to filter the contrast medium well enough and that it does not cause any further damage.
- Images will be sent to a radiologist for interpretation then back to your doctor to review with you.
- There are no restrictions after a CT scan, resume activities as tolerated. To flush contrast fluid quickly, drink as much non-caffeinated drinks as possible.
CTA (Computerized Tomography Angiography). Massachusetts General Hospital.
https://www.massgeneral.org/imaging/services/procedure.aspx?id=2257 Accessed January 29, 2019
CTA Chest
CTA chest is most commonly ordered by your doctor to evaluate in a timely fashion for blood clot(s) in your lung or if there are any torn artery walls (ruptured aortic aneurysm). It uses CT with a combination of intravenous dye injected into the arm vein to highlight vasculature in the chest and upper abdomen.
Safety
- No direct data suggests CT scan exposure links to cancer. There are some risks associated with radiation therefore the benefit must outweigh the risk.
- This test should be avoided in pregnant women.
- Diabetic precautions: If you are insulin-dependent diabetic, please remember to take your insulin as prescribed and compensate by drinking a fruit drink, etc. for the fasting you will be doing 2-3 hours prior to the test. Patients taking diabetic medications should take their dose as normal on the day of the test but stop for 48 hours after the test is done otherwise directed by your physician.
What to Expect
- You may be required blood work prior to the test to see how our kidneys are functioning if you have certain diseases. This is because IV contrast can damage your kidneys more if they are already struggling and this is something we want to avoid.
- You may be asked not to eat or drink 4-6 hours prior to the test.
- You will be asked to remove jewelry, wear a gown and likely undress from the waist up and will be injected with dye in IV form.
- You will be asked to lay flat on the CT scanner table very still. You will slide into the machine as the x-rays capture images of you from various angles.
- You may be asked to hold your breath for a few seconds during the test but the entire test should only last a few seconds.
- Images will be sent to a radiologists for interpretation then back to your doctor to review with you.
- There are no restrictions after a CT scan, resume activities as tolerated. To flush contrast fluid quickly, drink as much non-caffeinated drinks as possible.
CT Angiography. Medline Plus. https://medlineplus.gov/ency/article/007676.htm Accessed January 29, 2019.