PET/CT examination combines two modern imaging methods – positron emission tomography (PET) and computed tomography (CT) – which are performed simultaneously. The CT part of the examination uses X-rays to provide a detailed image of the shape and structure of internal organs. A contrast agent may be injected into a vein to better distinguish between individual organs.

Combined PET/CT is one of the most important diagnostic tools in modern medicine. It is most commonly used in oncological diagnostics. It is a very accurate method that can confirm or rule out the presence of a tumor, determine its activity, and determine whether the disease is spreading in the body. PET/CT also allows you to monitor how the patient responds to treatment and helps assess whether the disease is completely cured.

It is essential that you arrive for your examination at the exact time of your appointment. You may bring someone with you, but they must not be children or pregnant women. Please wear comfortable, warm clothing to the examination and do not wear any metal accessories.

Upon arrival, report to the reception desk, hand in your examination request form and insurance card. If you have findings from other examinations (CT, MR images), bring them with you. Then follow the staff’s instructions and wait in the waiting room until you are called.

If you suffer from claustrophobia, are in pain, are pregnant, or are breastfeeding, please inform the staff immediately before the examination.

The PET/CT examination is painless but time-consuming, so do not plan any other activities on the day of the examination.
To ensure the most accurate results, it is important to follow these instructions:

Before the examination

Avoid physical exertion 48 hours before the examination – do not exercise, play sports, go for long walks, or carry heavy objects.

Follow a low-sugar and low-starch diet 24 hours before the examination.

Not suitable: sweet and starchy foods, sweetened drinks.

Suitable: boiled, baked, or grilled meat, vegetables, mushrooms, eggs, smoked meats.

Last meal – a light dinner the day before the examination.

Do not eat on the day of the examination, but you may drink water, mineral water, or unsweetened tea (the recommended amount is 1–1.5 liters).

You may eat after the examination – bring food with you.

Medications

If you regularly take medications, take them as usual unless our staff advises you otherwise.
It is advisable to temporarily discontinue diabetes medications (tablet forms) – we will discuss the exact procedure with you by phone.

We assess each patient individually, so please follow the instructions provided by our staff over the phone.

If you have diabetes and are being treated with diet or pills, follow the above preparation instructions. If you are being treated with insulin, no change in lifestyle is necessary. Do not change your diet, and do not administer (take) insulin or pills for sugar the evening before the examination and on the morning of the examination. Take them with you.

The entire PET/CT examination takes approximately 3 hours and consists of several stages:

1. Preparation before administration

This stage involves administrative admission, patient instruction and signing of the informed consent form, insertion of an intravenous cannula (needle into a vein), and checking blood sugar levels by taking a sample from a finger. This is followed by a short wait for the radiopharmaceutical to be administered.

2. Administration of the radiopharmaceutical

The patient is given a special drug intravenously – a so-called radiopharmaceutical, which contains a small amount of radioactive substance bound to glucose (sugar). The administration takes only a few minutes and poses no risk.

3. Waiting for the substance to distribute in the body

After administration, the patient rests in a separate box for about 60 minutes so that the radiopharmaceutical can distribute evenly throughout the body. During this time, it is important to remain still and avoid movement so that the substance is absorbed properly.

4. PET/CT scan

After the waiting period, the patient is moved to a room with a PET/CT scanner. During the examination itself, the patient lies motionless on a bed that slowly passes through the circular opening of the PET/CT camera. The examination takes approximately 20-30 minutes and can be performed with or without a contrast agent. The contrast agent is administered through an already inserted cannula, and its administration may cause a brief feeling of warmth or the urge to urinate – these sensations quickly subside.
The scanning itself is painless, but during the entire examination, it is necessary to lie still and breathe calmly and shallowly.

5. Processing of results and patient check-up

After scanning is complete, it takes approximately 30 minutes for the computer to process and generate an evaluable image. During this time, doctors will check the patient’s health and ensure that there have been no adverse reactions.

The radioactivity of the substance used usually decays by the following day, with some of it being excreted in the urine. To speed up its excretion, it is advisable to drink plenty of fluids.

On the day of the examination, avoid contact with children and pregnant women. The radiopharmaceutical has no negative effect on you, so you can continue your normal activities without concern.

After the radioactive substance is administered, it spreads throughout the body via the bloodstream. During the examination, doctors monitor how individual cells absorb the substance – whether they consume more or less glucose than normal. It is these differences that help to detect pathological changes.

PET/CT is most commonly used in oncological diagnostics. This is because cancer cells consume much more glucose than healthy cells. The radioactive substance accumulates in them and releases a larger amount of positrons, making the affected areas appear more prominent on the image.

PET/CT thus makes it possible to detect the presence of a tumor, determine its activity and extent, and monitor how the body responds to treatment.