title: Shielding effects of body - shields for 3D PET.
abstract: We analyzed basic physics characteristics of body-shields which have been considered for screening out radioactivity outside the field of view (OFOV) in positron emission tomography (PET). Phantom experiments were performed with simple rectangular body-shields. A Monte Carlo simulation technique was used to analyze the experimental results and to simulate cases that were not examined experimentally. It was confirmed that the body-shields effectively reduced unwanted radiations from OFOV radioactivity for one of the latest commercial PET scanners, the ECAT EXACT HR(+). The geometrical conditions were the most important factor in determining the shielding effect. The shield thickness should be large enough to keep the shield-scatter component low. The body-shield should be carefully designed to minimize the gap between the body-shield and radioactive distribution as much as possible to maximize the shielding effects, and to be applicable to clinical diagnoses.
authors.affiliation: Kitasato University, Allied Health Sciences. hasegawa@kitasato-u.ac.jp
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Hasegawa
authors.forename: Hideo
authors.initials: H
authors.lastname: Murayama
authors.forename: Hajime
authors.initials: H
authors.lastname: Matsuura
authors.forename: Taiga
authors.initials: T
authors.lastname: Yamaya
authors.forename: Shuji
authors.initials: S
authors.lastname: Tanada
mesh_terms: D004867:Equipment Design; D021621:Imaging, Three-Dimensional; D009010:Monte Carlo Method; D019047:Phantoms, Imaging; D011835:Radiation Protection / Q000379:methods*; D014055:Tomography, Emission-Computed