Performance Characteristics of a New LSO PET/CT Scanner With Extended Axial Field-of-View and PSF Reconstruction
Performance Characteristics of a New LSO PET/CT Scanner With Extended Axial Field-of-View and PSF Reconstruction
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DOI：
10.1109/tns.2009.2015764
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发表时间：
2009-06-01
影响因子：
1.8
通讯作者：
Townsend, David W.
中科院分区：
文献类型：
--
作者：
Jakoby, Bjoern W.;Bercier, Yanic;Townsend, David W.
一种新的氧正硅酸(LSO)PET/CT组合扫描仪已被开发出来，其轴向视野(FOV)为21.8 cm(Bioggraph TruePoint PET/CT with TrueV；西门子分子成像)，并已应用于临床。该扫描仪包括最近宣布的点扩展函数(PSF)重建算法。PET组件包括四个环，共48个探测器块，横截面为5.4厘米x 5.4厘米。每个块由4x4x20 mm(3)元素组成的13x13矩阵。数据采集的符合时间窗为4.5 ns，能量窗为425-650keV。根据最近修订的国家电气制造商协会(NEMA)NU 2-2007标准对新扫描仪的物理性能进行了评估，并将结果与之前的PET/CT设计进行了比较，该设计采用了轴向覆盖16.2厘米的三环块检测器(Bioggraph TruePoint PET/CT；西门子分子成像)。除了模体测量外，还估计了一系列不同体重(42-154公斤)患者的患者噪声当量计数率(NECR)。两种扫描仪的平均空间分辨率相同：在距横向视野中心1 cm和10 cm处分别为4.4 mm(半高宽)和5.0 mm(半高宽)。Bioggraph TruePoint和Bioggraph TruePoint TrueV的散射分数相当于32%。与三环设计相比，采用平滑随机校正(1R)的系统灵敏度和峰值NECR分别提高了82%和73%。使用TrueV的Bioggraph TruePoint PET/CT的轴向覆盖范围扩大带来的灵敏度增加，应该可以在不影响诊断图像质量的情况下减少扫描时间或注射剂量。对比度的改善与PSF重建潜在地提供了对小病变的增强的可探测性。
A new combined lutetium oxyorthosilicate (LSO) PET/CT scanner with an extended axial field-of-view (FOV) of 21.8 cm has been developed (Biograph TruePoint PET/CT with TrueV; Siemens Molecular Imaging) and introduced into clinical practice. The scanner includes the recently announced point spread function (PSF) reconstruction algorithm. The PET components incorporate four rings of 48 detector blocks, 5.4 cm x 5.4 cm in cross-section. Each block comprises a 13 x 13 matrix of 4 x 4 x 20 mm(3) elements. Data are acquired with a 4.5 ns coincidence time window and an energy window of 425-650 keV. The physical performance of the new scanner has been evaluated according to the recently revised National Electrical Manufacturers Association (NEMA) NU 2-2007 standard and the results have been compared with a previous PET/CT design that incorporates three rings of block detectors with an axial coverage of 16.2 cm (Biograph TruePoint PET/CT; Siemens Molecular Imaging). In addition to the phantom measurements, patient Noise Equivalent Count Rates (NECRs) have been estimated for a range of patients with different body weights (42-154 kg). The average spatial resolution is the same for both scanners: 4.4 mm (FWHM) and 5.0 mm (FWHM) at 1 cm and 10 cm respectively from the center of the transverse FOV. The scatter fractions of the Biograph TruePoint and Biograph TruePoint TrueV are comparable at 32%. Compared to the three ring design, the system sensitivity and peak NECR with smoothed randoms correction (1R) increase by 82% and 73%, respectively. The increase in sensitivity from the extended axial coverage of the Biograph TruePoint PET/CT with TrueV should allow a decrease in either scan time or injected dose without compromising diagnostic image quality. The contrast improvement with the PSF reconstruction potentially offers enhanced detectability for small lesions.