[Positron emission tomography in cardiological diagnosis: principles and clinical application]

Positron emission tomography (PET) is an emerging new cardiac imaging modality which allows sophisticated tissue characterization using radiopharmaceuticals. This technique provides absolute quantification of regional tracer concentration using short-lived isotopes such as carbon-11, oxygen-15 and nitrogen-13, which can be easily incorporated in many compounds without changing their biological behaviour. These technical advantages are somewhat offset by the high cost of this technology which includes camera as well as on site cyclotron required for the preparation of radiopharmaceuticals. Recent clinical dates suggest that unique information can be obtained with PET. Using blood flow tracers in combination with PET, coronary artery disease can be detected and localized with high diagnostic accuracy. First studies comparing Tl-201 SPECT and PET in the same patient population indicate diagnostic superiority of PET. In combination with tracer kinetic models, regional myocardial blood flow can be quantitated and the functional significance of coronary artery stenosis defined by regional coronary reserve measurements. The assessment of regional glucose metabolism by PET with the tracer F-18 deoxyglucose has received wide clinical acceptance. Metabolic imaging in patients with advanced coronary artery disease allows the delineation of ischemically compromised but viable myocardium. Selection of patients for revascularization based on this scintigraphy tissue characterization has been shown to have a high predictive value for subsequent tissue recovery. Comparison of PET/FDG imaging with thallium-201 scintigraphy for assessment of tissue viability indicate that, in patients with fixed thallium-201 defects, additional diagnostic information can be obtained by this more expensive technology.(ABSTRACT TRUNCATED AT 250 WORDS)