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About PET-CT in general

Cellular imaging: the positron emission tomography (PET)

PET is a diagnostic procedure that enables quick, accurate and safe examination of most malignant tumorous diseases, several cardiological and central nervous system diseases and inflammatory diseases. PET is a camera which is capable of taking images of functions of the human body at cellular and molecular level thus revealing the pathological processes in the human body.

Physicians use PET diagnostics at first place for early detection of malignant tumorous diseases, for determining the stage of them and to assess the efficacy of the applied treatments. The PET examination significantly improves the accuracy of the diagnosis, which leads to change of the applied therapy in case of one third of the patients.

It is estimated that in Hungary there are more times ten thousand cancer patients who would need a PET examination annually.


The essence of the PET examination

PET on the contrary to CT (computer tomography) and MRI (magnetic resonance imaging) does not explore the anatomical and structural changes of the body, but provides functional information on biochemical processes of cells and tissues and on physiological processes of the body.

During the PET examination the patient is administered a substance marked with a radioactive isotope, in an intravenous injection. The distribution of this tracer substance in the body is visualized by the help of the PET camera.

In most cases we mark grape-sugar (glucose) with a positron-emitting isotope. The administered sugar-like substance is taken up by the cells depending on the intensity of their metabolism. The more intensive the cellular metabolism is, the higher amount of sugar is consumed during a certain period of time. The cancer cells proliferate without control, they utilize significantly more sugar than normal cells. Inversely, dead cells or cells with decreased metabolism consume significantly less sugar than normally. Thus the examination enables the detection of the viable cancer tissue and to separate them from dead tumorous parts after a successful therapy. The PET examination can not only be used in tumor diagnostics but provides important clinical information in case of certain cardiological and neurological diseases. For instance in case of patients having suffered a myocardial infarction it estimates the viability of the cardiac muscle before a planned operation which may predict the success of the intervention. But at the same time it is a very sensitive method for identification of certain diseases of the central nervous system and for exploration of hidden inflammatory foci.

In state-of-the-art PET diagnostic equipment the PET and the CT camera is integrated in one combined imaging system and that is why it is called PET-CT. The PET-CT equipments – combining the advantages of the two subunits – provide anatomical and functional information about a patient in only one examination.