Frequently asked questions

How is the investigation performed?

A small amount of radioactive material – the tracer – will be injected into a peripheral vein.

For a renal examination you will be asked to drink 1 L of water prior to the injection. After the tracer is administered, depending on which type of scan is being performed, the imaging will be done in one of our modern scanners. Imaging is done either immediately, a few hours later, or even several days after administration of the radiotracer.

The injected tracer will accumulate in certain organs, tissue or cells, where it will emit energy as gamma rays. The gamma rays are detected by the scanner and reconstructed by a computer to produce images and measurements of organs and tissues.

Imaging time, the time you will have to spend in the scanner, varies, generally ranging from 20 to 45 minutes. While the images are being obtained, it is important that you remain as still as possible.

After the procedure, a physician with specialized training in nuclear medicine checks the quality of the images to ensure that an optimal diagnostic study has been performed. A final description and conclusion will be forwarded to the referring physician who will inform you about the result.

How do you prepare for an investigation?

The preparation is different depending on the diagnostic investigation.

PET and PET/CT scans require fasting for 6 hours. You may drink water, tea or coffee – but you may not eat for 6 hours prior to the PET scan and NO added sugar nor milk in coffee or tea. If you have diabetes special recommendations apply, if in doubt please contact us.

Cardiac exams including stress test require no caffeine for 24 hours prior to the scan (thus no coffee, tea, chocolate or soft drinks as cola or Faxe Kondi). It may also require pausing of certain medications prior to the examination, if in doubt please contact us.

Thyroid scans may require cessation of certain medications prior to the scan. In that case you will be informed by your referring physician.

Is Nuclear medicine safe?

Nuclear medicine procedures are among the safest diagnostic imaging exams available.

As a patient undergoing a nuclear medicine examination you will only receive a very small amount of radioactivity from the radiopharmaceutical injected, just enough to provide sufficient diagnostic information.

In most cases the amount of radiation from a nuclear medicine procedure is comparable to that of a diagnostic X-ray. Together with the referring physician, the nuclear medicine physician will select the most appropriate examination for the particular medical problem, thereby avoiding any unnecessary radiation exposure.

Special precautions apply to pregnant and lactating women. Thus, if you are, or could be pregnant, or if you are lactating please inform your physician or contact us directly prior to the examination.

What is clinical physiology and nuclear medicine?

Clinical physiology and nuclear medicine is medicine specializing in the examination of organ function and diagnosis.

In nuclear medicine examinations are based on the use of small amounts of radioactive materials (tracers) evaluating the function of the organ, tissue or bone. In clinical physiology the organ function is measured directly by physiological measurements without use of radioactive material, as lung function and blood pressure. The aim is to assess organ function rather than morphology. This is how our examinations differ from X-ray or ultrasound that determines the presence of disease based mainly on their structural appearance or anatomy.

For nuclear medicine investigations a radiotracer is injected into the body, or inhaled as a gas and eventually accumulates in the organ or area of the body being examined. Radioactive emissions from the radiotracer are detected by a special camera or imaging device that produces pictures and detailed molecular information: Gamma camera, SPECT or PET scanner.

Positron emission tomography (PET)

PET is a nuclear medical imaging technique, by use of positron emitting tracers, that produces a three-dimensional image or picture of functional processes in the body.

Three-dimensional images of tracer concentration within the body are then reconstructed by computer analysis. Most modern scanners are combined PET and CT scanners enabling imaging of function (by PET) and detailed anatomy (by CT) during the same session, in the same machine. The most frequent indication for performing a PET/CT scan is diagnosing cancer and/or to explore the possibility of cancer metastasis. The most frequently used tracer is FDG, an analogue of glucose, where high FDG uptake shows the high tissue metabolic activity of cancer.

Other radiotracers are used in PET to image the tissue concentration of other types of molecules: PiB for the brain (dementia) and Rubidium for examination of the heart (ischemic heart disease).