Performance of the new generation of whole-body PET/CT scanners:: Discovery STE and discovery VCT
Performance of the new generation of whole-body PET/CT scanners:: Discovery STE and discovery VCT
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DOI：
10.1007/s00259-007-0493-3
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发表时间：
2007-10-01
影响因子：
9.1
通讯作者：
Knuuti, J.
中科院分区：
文献类型：
--
作者：
Teraes, M.;Tolvanen, T.;Knuuti, J.
目的新型GE Discovery STE和Discovery VCT分别联合收割机将16层和64层CT与PET相结合。PET扫描仪有一个8x 6矩阵（6.3x4.7x30 mm（3））的新BGO探测器块。本研究的目的是测试新的PET扫描仪的性能。由于前端电子设备的改进，结果2D（3D）模式下距视场中心（R1）1cm处的轴向分辨力FWHM为4.87mm（5.12 mm），并且在偏离中心10 cm处（R10）径向为5.70 mm（5.89 mm），切向为5.84 mm（5.47 mm）。轴向分辨率为4.4 mm（5.18 mm）（R1）和5.99 mm（5.86 mm）（R10）。灵敏度为2.3 cps/kBq（8.8 cps/kBq）（R 0，视野中心）和2.3 cps/kBq（8.9 cps/kBq）（R10）。在能量为375 keV的2D模式下，系统散射分数为21.4%（在更高能量425 keV的3D模式下为33.9%）。峰值噪声等效计数率（k=1）在43.9 kBq/ml（2D）时为84.9 kcps，在12.1 kBq/ml（3D）时为67.6 kcps。在图像质量测量中，热球与10至22 mm直径球的背景对比度在14%至68%之间变化，3D模式略好于2D模式。结论GE公司的新型STE和VCT PET/CT系统在不降低灵敏度的前提下提高了空间分辨率。与基于LYSO晶体的GE Discovery RX相比，分辨率和散射分数相当，计数率能力较低，但灵敏度较高。
Purpose The new GE Discovery STE and Discovery VCT respectively combine 16-slice and 64-slice CT with PET. The PET scanner has a new BGO detector block of 8x6 matrix (6.3x4.7x30 mm(3)). The aim of this study was to test the performance of the new scanner.Methods The PET performance evaluation was done using NEMA methodology. Owing to improved front-end electronics, the system was tested with different energy window and coincidence timing settings.Results Transaxial resolution FWHM for 2D(3D) mode at 1 cm offset from the centre of the field of view (R1) was 4.87 mm (5.12 mm) and at 10 cm off centre (R10) radially 5.70 mm (5.89 mm) and tangentially 5.84 mm (5.47 mm). The axial resolutions were 4.4 mm (5.18 mm) (R1) and 5.99 mm (5.86 mm) (R10). The sensitivities were 2.3 cps/kBq (8.8 cps/kBq) (R0, centre of field of view) and 2.3 cps/kBq (8.9 cps/kBq) (R10). The system scatter fraction was 21.4% in 2D at an energy of 375 keV (33.9% in 3D mode at a higher energy of 425 keV). Peak noise equivalent count rates (k=1) were 84.9 kcps at 43.9 kBq/ml (2D) and 67.6 kcps at 12.1 kBq/ml (3D). In image quality measurement the hot sphere to background contrast with 10- to 22-mm diameter spheres varied from 14% to 68%, being slightly better in 3D than in 2D mode. Cold sphere contrast was 67% in 2D and 59% in 3D mode.Conclusion GE's new STE and VCT PET/CT systems have improved spatial resolution without loss in sensitivity. When compared with the LYSO crystal-based GE Discovery RX, the resolution and scatter fraction are comparable, the count rate capability is lower but the sensitivity is higher.