Cardiac denervation is associated with progressive left ventricular (LV) dysfunction, ventricular arrhythmias, and sudden cardiac death (SCD) in heart failure (HF). In this regard, it is important to evaluate cardiac-specific sympathetic nervous system (SNS) function. The radiotracer Iodine-123 meta-iodobenzylguanidine (123I-mIBG) can noninvasively evaluate presynaptic SNS function. Recent multicenter trials have shown 123I-mIBG to have strong predictive value for fatal arrhythmias and cardiac death in HF. 123I-mIBG was initially developed in the USA in the 1970s. In 1992, the Japanese Ministry of Health and Labour approved 123I-mIBG for the assessment of cardiac function. Following approval, the Japanese nuclear cardiology community developed 123I-mIBG imaging services in various medical centers. Japanese groups have been trying to establish the clinical utility of 123I-mIBG and standardize parameters for data acquisition and image analysis. The US Food and Drug Administration (FDA) has approved clinical use of 123I-mIBG for cardiac and non-cardiac imaging. However, clinical use of 123I-mIBG in the US has been very limited. The number of 1123I-mIBG studies in Japan has also been limited. There are similarities and differences between the two countries. To establish the clinical utility of 123I-mIBG in both countries, it is important to characterize the situations of 123I-mIBG in each.
Myocardial perfusion imaging (MPI) using advanced PET technology is increasingly used for non-invasive detection and evaluation of coronary artery disease (CAD), but is still limited for clinical use. Recently, 18F labeled PET perfusion tracers have been actively developed as a novel class of PET MPI agents to overcome the disadvantages of conventional PET MPI tracers (15O-labelled water, 13N-ammonia, and 82Rb chloride). This review summarizes the advantages and the feasibility of recent developed 18F labeled tracers in clinical practice.
Oxygen-15-labeled water (15O-H2O) is used as a radiopharmaceutical tracer with positron emission tomography (PET). Its short radioactive half-life permits consecutive rest and stress imaging acquisition while requiring an on-site cyclotron near a PET imaging system. 15O-H2O PET has the disadvantage of being less than ideal for visual assessment; however, its high extraction fraction allows for highly accurate quantification of myocardial blood flow (MBF). Therefore, 15O-H2O is considered to be a gold standard for MBF quantification. This is one of the great advantages of 15O-H2O PET over other PET myocardial perfusion imaging modalities. The purpose of this review is to provide the advantages and characteristics of 15O-H2O PET.