Computed tomography

The purpose of this leaflet is to provide the patient with information about computed tomography (CT scan) and how to prepare for it.

General information

CT scans are performed in the C-block of East Tallinn Central Hospital at Ravi 18 and in the X-block of the Magdalena unit at Asula põik 5. An appointment for the CT scan will be scheduled by your doctor. To schedule an appointment yourself, call 620 7200. If you cannot come to the appointment at the agreed time, please notify us immediately by calling the same number.

What is computed tomography?

Computed tomography is an X-ray machine connected to a computer that allows layered and three-dimensional images to be taken of the human body. In a CT scan, X-rays pass through the tissues in several directions and their absorption is measured with detectors at many points of the machine. The information obtained is processed by a computer. The amount of radiation used in the scan is higher than in a normal X-ray, and the examination procedure is therefore performed only for a medically important indication. Depending on the diagnosis, it may be necessary to use a contrast agent that is injected into a vein. The contrast agent contains iodine.

Contraindications

X-rays are harmful to a developing foetus. If you are pregnant or if you suspect pregnancy, be sure to notify the referring physician and the radiology technician at the CT office. During pregnancy, a CT scan is only allowed in cases of extreme urgency.

Contraindications to the CT scan with a contrast agent are as follows:

• Iodine allergy – after intravenous injection of a contrast agent, an allergic reaction may occur:

  • skin rash

  • itching

  • nausea

  • vomiting

  • increased body temperature

If you have a history of reactions to a contrast agent, inform the referring physician and the staff at the CT office.

• Renal failure.

• Diabetes – if necessary, special preparation will be done and you will be monitored after the scan (not an absolute contraindication).

Preparing for the examination procedure

Metal objects create shadows on the image of a CT scan, so there must be no such objects in the area examined.

When coming to the scan, keep the following in mind:

• Put on something light and comfortable that is easy to remove when needed. Avoid clothing with metal buttons, zippers, hooks, etc. It is recommended to come to the scan without jewellery and other accessories.

• If necessary, all metal jewellery and watches as well as belts and hair clips must be removed for the examination procedure.

If your doctor has referred you for a CT scan of your abdomen or pelvis, you will need to prepare as follows:

• Do not eat for 2-4 hours before the scan.

• On the day of the scan, it is recommended to drink more fluids to better assess the abdominal and pelvic organs.

Course of the examination procedure

The CT scan lasts 10 to 30 minutes. A CT scan of the abdomen can take up to one hour. If necessary, a vein cannula is placed in your hand, through which an iodinated contrast agent is injected. During the injection of the contrast agent, you may feel hot and have a metallic taste in your mouth that goes away in a few seconds. During the scan, you lie on a table that slides back and forth in the CT machine. It is important to lie still. Sometimes you will be asked to hold your breath for a few seconds during the scan. A radiology technician will monitor your condition throughout the examination procedure.

After the examination procedure

• You can leave immediately after the examination procedure.

• The contrast agent has no effect on your rate of reaction or attention.

• After the contrast-enhanced scan, you should drink plenty of fluids (preferably 1.5 to 2 litres of water) on the same day to remove the contrast agent from your body more quickly.

• Delayed reactions to the contrast agent are uncommon (less than 1 case per 1000 patients). In the event of the following symptoms, seek emergency medical attention or call an ambulance immediately:

  • decreased blood pressure

  • increased heart rate

  • breathing difficulties

  • anxiety and confusion

  • bluish lips

• If you have diabetes, you should be monitored for the possible development of renal insufficiency.

• You should contact your doctor or GP immediately if you experience any of the following symptoms during the days after the examination:

  • muscle cramps at night

  • swelling of the legs

  • swelling around the eyes in the morning

• • increased urinary frequency (especially at night)

  • fatigue

  • loss of appetite

  • sleep disorders

  • dry and itchy skin

The result of the examination procedure

A radiologist will evaluate the images taken and send the result to your doctor. Receiving images on an information carrier (CD, memory stick) is subject to a fee. The price of the service is given in the price list of paid services on East Tallinn Central Hospital website www.itk.ee

Additional information

If you have any questions about the examination procedure, please contact the helpline for radiological examinations. When calling the helpline, you will not be able to book an appointment or receive information about the results of the examination.

You can reach the helpline from 08:00 to 16:00 Monday to Friday.

• telephone 666 5166

• e-mail radioloogiainfo [at] itk.ee (radioloogiainfo[at]itk[dot]ee).

ITK979

Approved by the decision of the Care Quality Commission of East Tallinn Central Hospital on 25.11.2020 (protocol no. 13-20)