Brain Perfusion Scintigraphy is a functional nuclear imaging technique performed to evaluate regional cerebral perfusion. The cerebral blood flow is closely linked to neuronal activity, the activity distribution is presumed to reflect neuronal activity levels in different areas of the brain. A lipophilic, PH-neutral radiopharmaceutical (most commonly99m Tc-hexamethylpropyleneamine oxime [HMPAO] and99m Tc-ethylene cysteine