PET系统中Lu-176本底辐射的影响

Advantages and Disadvantages of the Lutetium-176 Intrinsic Radiation in the PET System

正电子发射断层(positron emission tomography,PET)成像系统的探测器广泛采用具有高阻止本领、高光输出和较短发光衰减时间特性的含镥闪烁晶体。天然镥(Lu)元素中含有丰度2.6%的Lu-176长半衰期放射性同位素,包括一个β衰变和三个级联的γ衰变。Lu-176本底辐射对PET探测器引入随机事件,影响系统成像性能,但该特性又可以被合理的开发应用。本文主要介绍Lu-176本底辐射在PET系统中的特性,由此带来的不利影响,以及其有利的应用开发。

Lutetium(Lu)based scintillators such as LSO and LYSO,are widely used in PET detectors due to their high stopping power for 511 keV gamma rays,high light yield and short decay time.The abundance of Lu-176 is 2.6% in natural Lu,and the Lu-176 is a long-lived radioactive isotope with a beta decay and three major simultaneous gamma decays.This phenomenon introduces random events to PET systems that affects the system imaging performance.On the other hand,the advantages of intrinsic radiation of Lu-176 continue to be exploited and utilized.The Lu-176 intrinsic radiation in PET detectors are reviewed,including the characteristic,the adverse effects,and its useful applications.