Current status and perspectives of nuclear cardiology.

Nuclear cardiology has long been used to identify myocardial ischemia for appropriate treatment strategies for stable coronary artery disease (CAD). After the Ischemia Trial, it is time to reevaluate the significance of ischemia assessment. Functional imaging continues to play pivotal role in detecting microcirculatory disturbances. PET provides a clear image of blood flow distribution and is useful for the quantitative evaluation of myocardial flow reserve (MFR), which plays an important role in predicting treatment strategies and improving prognosis in CAD. Heart failure has become a major area of focus in cardiovascular medicine. Radionuclide imaging has been widely applied in this field. FDG PET is useful in identifying cardiac sarcoidosis and active inflammation. Clinical values of I-123 MIBG and BMIPP SPECT have been reported worldwide from Japan. Additionally, clinical experiences of Tc-99m pyrophosphate imaging have recently gained attention for assessing cardiac amyloidosis. Cardiac PET/CT and PET/MR imaging permit combined assessment of metabolic/functional/structural analyses of various cardiac diseases. While other non-invasive imaging modalities have rapidly been developed, the roles of radionuclide imaging remain to be valuable for early and accurate diagnosis and patient management in most cases of chronic CAD and various cardiovascular diseases.