Introduction The medical radioisotopes are used for diagnostic and therapeutic purposes, as well as metabolism and physiological function researches in modern medicine. If a short-lived radioisotope emits a predominant or single γ-rays of 60～300 keV, it is of greater advantage since single photon emission computed tomograph(SPECT) can be performed; similarly β~+ emitters are also of great significance since three dimensional high resolution scans can be obtained via Introduction The medical radioisotopes are used for diagnostic and therapeutic purposes, as well as metabolism and physiological function researches in modern medicine. If a short-lived radioisotope emits a predominant or single γ-rays of 60 ~ 300 keV, it is of greater advantage since single photon emission computed tomograph (SPECT) can be performed; similarly β ~ + emitters are also of great significance since three dimensional high resolution scans can be obtained via