This paper investigates the performance of 1 mm resolution cadmium zinc telluride (CZT) detectors for positron emission tomography (PET) capable of positioning the 3D coordinates of individual 511 keV photon interactions. The detectors comprise 40 mm x 40 mm x 5 mm monolithic CZT crystals that employ a novel cross-strip readout with interspersed steering electrodes to obtain high spatial and energy resolution. The study found a single anode FWHM energy resolution of 3.06 +/- 0.39% at 511 keV throughout most of the detector volume. Improved resolution is expected with properly shielded front-end electronics. Measurements made using a collimated beam established the efficacy of the steering electrodes in facilitating enhanced charge collection across anodes, as well as a spatial resolution of 0.44 +/- 0.07 mm in the direction orthogonal to the electrode planes. Finally, measurements based on coincidence electronic collimation yielded a point spread function with 0.78 +/- 0.10 mm FWHM, demonstrating 1 mm spatial resolution capability transverse to the anodes-as expected from the 1 mm anode pitch. These findings indicate that the CZT-based detector concept has excellent performance and shows great promise for a high-resolution PET system.
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机译：本文研究了用于定位正电子511 keV光子相互作用的3D坐标的1 mm分辨率的碲化镉锌（CZT）检测器的性能。该探测器包括40 mm x 40 mm x 5 mm的单片CZT晶体，这些晶体采用新颖的交叉带读数和散布的操纵电极来获得高空间和能量分辨率。研究发现，在整个探测器体积中，单个阳极的FWHM能量分辨率在511 keV时为3.06 +/- 0.39％。适当屏蔽前端电子设备有望提高分辨率。使用准直光束进行的测量建立了操纵电极在促进增强的跨阳极电荷收集方面的功效，以及在垂直于电极平面的方向上具有0.44 +/- 0.07 mm的空间分辨率。最终，基于重合电子准直的测量产生了点扩散函数，FWHM为0.78 +/- 0.10 mm，这证明了与阳极垂直的1 mm空间分辨能力-如从1 mm阳极间距所预期的那样。这些发现表明，基于CZT的检测器概念具有出色的性能，并显示出高分辨率PET系统的广阔前景。
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