Badawi R D, Lodge M A, Marsden P K
Guy's Clinical PET Centre, Division of Radiological Sciences, UMDS, St Thomas' Hospital, London, UK.
Phys Med Biol. 1998 Jan;43(1):189-205. doi: 10.1088/0031-9155/43/1/012.
Accurate normalization of lines of response in 3D PET is a prerequisite for quantitative reconstruction. Most current methods are component based, calculating a series of geometric and intrinsic detector efficiency factors. We have reviewed the theory behind several existing algorithms for calculating detector efficiency factors in 2D and 3D PET, and have extended them to create a range of new algorithms. Three of the algorithms described are 'fully 3D' in that they make use of data from all detector rings for the calculation of the efficiencies of any one line of response. We have assessed the performance of the new and existing methods using simulated and real data, and have demonstrated that the fully 3D algorithms allow the rapid acquisition of crystal efficiency normalization data using low-activity sources. Such methods enable the use of scatter-free scanning line sources or the use of very short acquisitions of cylindrical sources for routine normalization.
三维正电子发射断层显像（PET）中响应线的精确归一化是定量重建的前提条件。当前大多数方法都是基于组件的，计算一系列几何和固有探测器效率因子。我们回顾了几种用于计算二维和三维PET探测器效率因子的现有算法背后的理论，并对其进行扩展以创建一系列新算法。所描述的三种算法是“全三维”的，因为它们利用来自所有探测器环的数据来计算任何一条响应线的效率。我们使用模拟数据和真实数据评估了新方法和现有方法的性能，并证明全三维算法允许使用低活度源快速获取晶体效率归一化数据。此类方法能够使用无散射扫描线源或对圆柱形源进行非常短时间的采集来进行常规归一化。
