Computed tomography (CT) is a test done with a machine with a hole inside an X-ray tube. The patient stretches without moving on a table that moves up and down, in and out, while the x-ray tube rotates around his body. Thus, images of the body can be generated from different angles. It is especially useful because it shows very clearly different types of tissues.
What does it consist of?
CT uses special x-ray equipment to obtain images of the body from different angles. Each time the x-ray tube and detector rotate, an image of a very thin section of the part of the body to be studied is obtained. About a thousand images are taken in each rotation. It’s like examining a very thinly sliced piece of bread. A computer takes care of reassembling all the slices, one after another, to produce a highly detailed multi-dimensional view of the inside of the body.
What is it normally used for?
CT is especially useful because it shows very clearly different types of tissues, lungs, bones, soft tissues, and blood vessels. It allows you to diagnose problems such as cardiovascular diseases, infections, trauma, musculoskeletal disorders and cancer, as well as to monitor and plan the type of medical or surgical treatment and its response.
How it is performed?
Technical personnel stretch the patient on the CT table. A pillow can be used to better maintain the position. When the test begins, the table moves slowly through the interior of the CT scan. Depending on the part of the body being examined, the patient may or may not perceive movement. Sometimes, to be able to see certain parts of the body better it is necessary to use a contrast. It is a liquid that is administered to the patient drunk or injected intravenously, depending on the type of test. The healthcare staff will inform you about the test, clarify any doubts and make you sign an informed consent document.
How do you have to prepare?
If there is no contrast for your test, you do not need to do any preparation. For tests that require contrast, it is best to fast six hours beforehand. Now, do not stop drinking water because you have to be well hydrated. There are some very specific CT tests that involve other interventions and therefore have other requirements. Your doctor should explain it to you in detail.
What will you experience during and after the test?
It does no harm. If it is with contrast, in most cases you will not notice anything. If it is drunk, you will notice an aniseed flavor. Some people notice a bit of heat. Nothing happens, it will go away in a couple minutes. If you experience any sensations other than those described, inform your nurse or technical staff immediately, as it could be a sign of an allergic reaction.
Who and where will you be tested?
The test will be performed by a specialist radiology technician. During the test the staff will not stay in the room, but will see and feel you all the time and, therefore, you will be able to communicate. The staff will ensure that you are well at all times.
Who will interpret the results?
The radiology specialist, who is a doctor who specializes in CT and other radiological examinations, analyzes and interprets the images and sends a signed report with his interpretation to the patient’s doctor. In the medical consultation, they will show you how you can get the results. In most cases, the results will come to your doctor to have them on the day you have the visit scheduled.
What are the most frequent examinations?
A CT scan of any part of the body can be done. The most frequent are to explore the central nervous system (especially the brain), the thorax and the abdomen. CT also has other applications, less frequent, but also valuable. The heart, intestine, or teeth can be studied to make implants. It can be used to visualize the area of the body to take tissue samples and also to visualize the area of the body to treat some tumors.
What special situations must be taken into account before taking the test?
You should always inform your doctor, nurse or technician:
- if you are pregnant;
- if you are breastfeeding;
- if you know that you may have an allergy to contrast;
- if you have diabetes, asthma, or heart, kidney, or thyroid disease;
- If you regularly take any medication and you must fast to be administered the contrast, you must report the medication you take; in most cases they will tell you not to stop taking it; there is no problem if you need to drink a little water;
- If you suffer from claustrophobia, you don’t need to worry because it is a very open device; anyway, if you consider it necessary, tell your doctor.
Department of Radiology / Policlinica Comarcal del Vendrell