Radiotracers for functional brain scintigraphy
What radiotracers are available for functional brain scintigraphy?
There are currently two single photon emission computed tomography (SPECT) radiotracers that are available to evaluate general brain function by measuring cerebral blood flow (CBF): technetium-99m ( 99m Tc) ethylcysteinate dimer (ECD) and 99m Tc hexamethylpropyleneamine oxime (HMPAO). These diffuse passively into the brain shortly after injection. Iodine-123 ( 123 I) ioflupane (DaTscan) is now available for visualizing and measuring the dopamine transporter (DaT) and is typically used for the evaluation of patients with movement disorders such as Parkinson’s disease (PD). There is one positron emission tomography (PET) radiotracer, fluorine-18 ( 18 F) fluorodeoxyglucose (FDG), which is available for the evaluation of general brain function by measuring cerebral glucose metabolism. Currently, several amyloid radiotracers are approved for evaluating patients with suspected Alzheimer’s disease (AD). There are many other radiotracers for evaluating all aspects of brain function including multiple neurotransmitter systems, but these are currently used only for research purposes.