A 32 mm x 32 mm x 22 mm monolithic LYSO:Ce detector with dual-sided digital photon counter readout for ultrahigh-performance TOF-PET and TOF-PET/MRI
A 32 mm x 32 mm x 22 mm monolithic LYSO:Ce detector with dual-sided digital photon counter readout for ultrahigh-performance TOF-PET and TOF-PET/MRI
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DOI：
10.1088/0031-9155/61/13/4929
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发表时间：
2016-07-07
影响因子：
3.5
通讯作者：
Schaart, Dennis R.
中科院分区：
文献类型：
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作者：
Borghi, Giacomo;Peet, Bart Jan;Schaart, Dennis R.
正电子发射断层扫描（PET）和组合的PET/磁共振成像（MRI）的新应用目前正在出现，例如在神经、乳腺和儿科成像领域。这些应用需要提高图像质量、减少剂量、缩短扫描时间和更精确的定量。这可以通过基于超高性能探测器的专用扫描仪来实现，该探测器应提供出色的空间分辨率、精确的交互深度（DOI）估计、出色的飞行时间（TOF）能力和高检测效率。在这里，我们介绍这样一个超高性能的TOF/DOI PET探测器，基于32 mm x 32 mm x 22 mm单片LYSO：Ce晶体。晶体的32 mm x 32 mm正面和背面耦合到数字光子计数器（DPC）阵列，即所谓的双面读出（DSR）配置。全数字探测器提供类似于1.1 mm半高全宽（FWHM）/类似于1.2 mm平均绝对误差的空间分辨率，以及类似于2.4 mm FWHM的DOI分辨率，10.2%FWHM的能量分辨率，以及147 ps FWHM的符合分辨时间。的时间分辨率接近最好的结果（135 ps的FWHM），迄今为止获得的小晶体从相同的材料耦合到相同的DPC阵列，说明了良好的校正光学和电子渡越时间的传播，可以实现在单片集成电路使用最大似然技术估计的相互作用的时间。对于数据缺失的事件（32个DPC芯片中最多有6个缺失），性能几乎没有下降，允许使用在实际采集条件下记录的几乎所有事件。此外，用于位置和时间估计的校准程序和计算方法遵循最近做出的改进，使其快速和实用，为在TOF-PET和TOF-PET/MRI系统中使用DSR单片闪烁体探测器开辟了现实的前景。
New applications for positron emission tomography (PET) and combined PET/magnetic resonance imaging (MRI) are currently emerging, for example in the fields of neurological, breast, and pediatric imaging. Such applications require improved image quality, reduced dose, shorter scanning times, and more precise quantification. This can be achieved by means of dedicated scanners based on ultrahigh-performance detectors, which should provide excellent spatial resolution, precise depth-of-interaction (DOI) estimation, outstanding time-of-flight (TOF) capability, and high detection efficiency. Here, we introduce such an ultrahigh-performance TOF/DOI PET detector, based on a 32 mm x 32 mm x 22 mm monolithic LYSO: Ce crystal. The 32 mm x 32 mm front and back faces of the crystal are coupled to a digital photon counter (DPC) array, in so-called dual-sided readout (DSR) configuration. The fully digital detector offers a spatial resolution of similar to 1.1 mm full width at half maximum (FWHM)/similar to 1.2 mm mean absolute error, together with a DOI resolution of similar to 2.4 mm FWHM, an energy resolution of 10.2% FWHM, and a coincidence resolving time of 147 ps FWHM. The time resolution closely approaches the best results (135 ps FWHM) obtained to date with small crystals made from the same material coupled to the same DPC arrays, illustrating the excellent correction for optical and electronic transit time spreads that can be achieved in monolithic scintillators using maximum-likelihood techniques for estimating the time of interaction. The performance barely degrades for events with missing data ( up to 6 out of 32 DPC dies missing), permitting the use of almost all events registered under realistic acquisition conditions. Moreover, the calibration procedures and computational methods used for position and time estimation follow recently made improvements that make them fast and practical, opening up realistic perspectives for using DSR monolithic scintillator detectors in TOF-PET and TOF-PET/MRI systems.