What is a CT Scan and what does it do?
A computed tomography (CT or CAT) scan is a simple, safe and painless examination that has been performed for many years. The scan produces a series of pictures and can detect many conditions that are not visible on regular x-rays. Your physician has ordered this examination to help make an accurate diagnosis of your condition. The results help determine the best course of treatment for you. During the scan, a thin beam of x-rays is focused on a specific part of your body, such as the head, chest, liver, spleen, pancreas, adrenal glands, kidneys, or spine. The x-ray tube moves rapidly around this site, taking multiple pictures which records the information and feeds it into a computer.
The computer then analyzes the information and makes an image on a monitor screen. During some CT scans, a contrast medium (commonly called "dye") is used to outline blood vessels or highlight organs of the body so they can be seen more easily. There are two types of contrast agents, intravenous and oral. Intravenous contrast is injected through a small needle into your arm, back of the hand, or via port-a cath. The oral contrast is drank before the exam. Sometimes both types are used.
Where does the test take place?
The CT scan(s) will be performed at the Charleston Cancer Center. We are located in suite #204 on the second floor.
How long does the CT Scan take?
A CT scan of the body can take around 7 minutes, while a scan of the head alone can take about 3-5 minutes. However, you will need to allow 45 minutes for the procedure. This time allows for blood to be drawn (if ordered by your doctor), paperwork to be completed and patient history questions to be answered. A member of the CCC staff will advise you on how to plan your schedule for the day of the exam.
Who performs the test?
Your physician will request the CT scan and a radiologist, who is a medical doctor that specializes in the use of x-rays for the diagnosis of medical conditions, will interpret or "read" the pictures. An A.R.R.T. Registered Radiologic Technologist, a person who has extensive training in the use of x-ray equipment, will make sure that your CT scan pictures are of the best quality and that you are as comfortable as possible throughout the procedure.
This guide provides a step-by-step description of what to expect before, during and after your CT scan. But please remember that it is only a guide. Some steps may vary depending on your condition.
What I can do to help make it a success?
A CT scan is usually painless. The machine does not touch you and you do not feel the x-rays. Occasionally, patients who are given an intravenous contrast medium experience a hot feeling at the time of the injection, which can be felt throughout their body, but this usually lasts only seconds and often a metalic taste or smell is noticed.
Be sure to carefully answer any questions asked about your general health. For example, tell them if you are pregnant, diabetic, and/or allergic to any foods or drugs. Let them know if you have had any contrast media in the past and if you had any side effects. Give them a complete list of any medications you may be taking now, including nonprescription medications.
It is important that the technologist knows if you are a diabetic and what medications you take to control it. Blood work may be necessary before your scan to determine if your kidneys will be able to process the contrast and excrete it from the body with your urine.
As with any other important diagnostic test, you may be asked to sign an informed consent to undergo a CT scan. That is your opportunity to ask any questions that will help you prepare for your test. You will be asked not to eat or drink anything during the two hours before your scan.
Please try to wear clothing that does not contain metal. If you are having a scan of your chest, abdomen, or pelvis, you may be asked to undress and put on a gown or scrubs for the scan. You will also be asked to remove any jewelry or metallic properties such as keys or necklaces so that it does not interfere with the x-ray imaging. Most abdominal and pelvic scans require that you drink a specially mixed oral contrast to enhance your stomach and intestines. This comes in many flavors and is also available in a powder form that can be mixed with a 20 ounce bottle of water. Oral prep is taken two hours before the start of your scan. Follow the directions that will be given to you at the time of scheduling your appointment. If your appointment is made over the phone, the prep can be sent to you through the U.S. Postal Service or someone may pick it up for you from the Charleston Cancer Center.
If you are having a CT scan of your head or face, you will be asked to remove dentures, glasses, hearing aids, earrings, hairpins, wigs, and any other objects that may be in the path of the x-ray beam. A locked cabinet with a key will be provided for your belongings.
What will happen during my CT exam?
What happens after my CT exam?
- You will be asked to lie on a table that is connected to the CT scanner. Then the part of your body that is to be scanned will be positioned in the middle of the large, doughnut-shaped scanner ring. This ring holds the x-ray tube and the electronic detector that sends information to the computer. There is no "tunnel" attached to the CT scanner and the CT staff will do everything possible to make you comfortable.
- A CT staff member will explain the procedure, answer any questions, and take preliminary scans to check your position on the table.
- If an Intravenous contrast medium is used, the technologist will inject it into a vein. The solution will be injected by a syringe or by an automatic injector. A tourniquet will be used to make the vein stand out for easier injection. A tourniquet is simply a band that is wrapped tightly around your arm, similar to, but smaller than, the cuff that is wrapped around your arm when you have your blood pressure taken. Notify a staff member if you have any discomfort in your arm during the injection.
- The table will move and a pre-recorded voice will give you breathing instructions. You will remain alone in the room after the procedure begins, but the technologist will watch you closely through an observation window and you can talk to them through a two-way intercom.
- The table may move a short distance every few seconds to position you for each new scan, or the table may move continuously very slowly. You will hear clicking or buzzing sounds as the mechanism in the scanner moves around your body, making images from many different angles. It is important that you lie very still during the procedure so the scanner can get the best possible pictures and please follow the breathing/swallowing instructions.
- After the exam is over, the images will be checked to make sure they contain all the needed information.
- After the technologist has a complete set of scans, the IV will be removed, a bandage will be applied and you can go home.
- Unless you have other tests scheduled, you may eat normal meals after the exam and your doctor has suggested that you drink plenty of fluids. Fluids will help eliminate the contrast medium from your body by natural routes.
- The radiologist will study all the scans, prepare a report and forward it to your physician. Please allow 48 hours for the report to reach your doctor. Your physician will discuss the results with you at your next office visit.