1GE Healthcare, Taipei, Taiwan, 2Department of Diagnostic Radiology, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan, 3Department of Nuclear Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan, 4Department of Neurology, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan, 5Department of Nuerosurgery, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan, 6Brain Research Center, National Yang-Ming University, Taipei, Taiwan