Tayebeh Hadizad - Department of Radioisotope, Nuclear Research Center, AOEI, Tehran, Iran
Gholamali Shabani - Department of Radioisotope, Nuclear Research Center, AOEI, Tehran, Iran
Reza Najafi - Department of Radioisotope, Nuclear Research Center, AOEI, Tehran, Iran

In recent years, several radiopharmaceuticals have been developed for imaging regional cerebral blood flow (rCBF) such as ۷۵Se labelled PIPSE and MOSE, ²º¹TI labelled DDC and ۹۹mTc labelled HMPAO. HMPAO with two asymmetric carbon atoms (At the ۳ and ۹ positions), produces d,۱ and meso isomers, only one of which is retained in the brain. Rapid intracellular conversion of ۹۹mTc-d,۱-HMPAO to hydrophilic ۹۹mTC species causes the complex becoming fixed in the brain. In this report we synthesized and characterized d,۱-HMPAO. Kit formulations have been done and biological characteristics of ۹۹mTc-d,۱-HMPAO have been examined.