[The place of positron-emission tomography in contemporary patient care].

Positron emission tomography (PET) is a unique method offering physicians unrivaled access to in vivo quantitative measurements. The PET studies are useful in many areas of establishing primary diagnosis, differential diagnosis, planning and monitoring therapeutical efficacy. As a clinical tool it has been shown to increase diagnostic accuracy. Unlike anatomical imaging modalities, such as CT and MR, PET permits assessment of chemical and physiological changes related to any function. PET images demonstrate pathological change long before they would be revealed by other imaging modalities like CT and MR. It produces images of molecular level of physiological function which can be used to measure many vital processes, including glucose metabolism, blood flow and perfusion, receptorligand binding rates, and oxygen utilization. The PET studies provide useful diagnostic information which may alter patient management and reduce the total cost of patient care. PET studies have made critical contributions to more cost-effective patient management in four clinical disciplines: cardiology, neurology, psychiatry and oncology. Recently, the clinical indications for PET have increased dramatically. Since Hungary's first PET center has been established at the University Medical School in Debrecen many studies additionally demonstrate that PET reduces overall cost of medical care, because it increases the certainty of diagnosis and clinical stage of disease, and therefore eliminates the expense of unnecessary testing or treatment.