[11C]Meta-Hydroxyephedrine PET/TC

Aim of the present review is to report the use of Positron Emission Tomography (PET) with [11C]- metahydroxyephedrine ([11C]mHED) in different clinical conditions, including heart failure, coronary artery disease, arrhythmogenic disorders, diabetes mellitus, idiopathic Parkinson's disease and adrenal tumors. [11C]mHED is a radio-labeled neurotransmitter PET tracer used to evaluate global and regional sympathetic presynaptic innervation in vivo, and firstly carried out in cardiac tissue in the 1990s. After the radiosynthesis and the injection of 740MBq of [11C]mHED with 2±0.5 Ci/?mole specific activity, the tracer is avidly retained in myocardium within 10 minutes and remains entrapped for at least 60 minutes. The transplanted heart is a good model to evaluate specificity of tracers for presynaptic innervation whose involvement in heart failure has been characterized in several studies using PET and [11C]mHED. In addition to transplanted heart, PET and [11C]mHED prognostic value has been also assessed in Diabetes Mellitus cardiac neuropathy and in neurological disorders related to Idiopathic Parkinson's disease. Neuronal imaging by PET may be also useful in determining the risk of sudden death in patients with viable but denervated myocardium after an infarction. In addition to the evaluation of neuronal cardiac disorders, PET with [11C]mHED has been proposed in oncological studies for the detection of adrenal tumors.