Pani Roberto, Pellegrini Rosanna, Cinti Maria Nerina, Trotta Carlo, Bennati Paolo, Betti Margherita, De Vincentis Giuseppe, Cusanno Francesco, Garibaldi Franco, Ridolfi Stefano, Majewsky Stan, Tsui Benjamin M W
Department of Experimental Medicine and Pathology, University "La Sapienza," Rome, Italy.
Cancer Biother Radiopharm. 2004 Feb;19(1):121-8. doi: 10.1089/108497804773391766.
Pinhole gamma camera imaging offers the ability to obtain high resolution images from single gamma ray emitting radiotracers playing a reasonable tradeoff between very small field of view (FoV) and sensitivity. On the other hand the total spatial resolution of a pinhole imaging device is predominantly affected by the detector intrinsic spatial resolution for reduced magnification factors. To design very compact pinhole SPET scanners with very high intrinsic spatial resolution, authors investigated a miniature gamma camera based on the newly developed Hamamatsu H8500 flat panel photomultiplier. The PSPMT was coupled to the following scintillation arrays: CsI(Tl) array with 0.2-mm, 1-mm, 1.4-mm pixel size and NaI (Tl) with 1-mm pixel size. The imaging performances were evaluated by 57Co spot and flood irradiations. NaI(Tl) array shows a better pixel identification for 1 mm pixel size, proving to be a good candidate to make a large area photodetector based on multi PSPMTs closely packed. Although CsI(Tl) array had the smallest pixel size, the low light output limited the best intrinsic spatial resolution to about 0.5 mm.
针孔伽马相机成像能够从单个发射伽马射线的放射性示踪剂获取高分辨率图像，在极小视野（FoV）和灵敏度之间实现了合理的权衡。另一方面，对于放大倍数降低的情况，针孔成像设备的总空间分辨率主要受探测器固有空间分辨率的影响。为了设计具有非常高固有空间分辨率的超紧凑型针孔单光子发射断层扫描（SPET）扫描仪，作者研究了一种基于新开发的滨松H8500平板光电倍增管的微型伽马相机。该光电倍增管与以下闪烁阵列耦合：像素尺寸为0.2毫米、1毫米、1.4毫米的碘化铯（铊）阵列以及像素尺寸为1毫米的碘化钠（铊）阵列。通过钴 - 57点源和泛光照射对成像性能进行了评估。碘化钠（铊）阵列对于1毫米像素尺寸显示出更好的像素识别能力，证明是基于紧密排列的多个光电倍增管制作大面积光电探测器的良好候选者。尽管碘化铯（铊）阵列具有最小的像素尺寸，但低光输出将最佳固有空间分辨率限制在约0.5毫米。
