Evaluation of a low-dose/slow-rotating SPECT-CT system
Evaluation of a low-dose/slow-rotating SPECT-CT system
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DOI：
10.1088/0031-9155/53/10/003
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发表时间：
2008-05-21
影响因子：
3.5
通讯作者：
Hutton, B. F.
中科院分区：
文献类型：
--
作者：
Hamann, M.;Aldridge, M.;Hutton, B. F.
构成GE Infinia Hawkeye-4 SPECT-CT扫描仪(鹰眼)一部分的4层CT与GE Discovery ST PET-CT系统(DST)中包含的诊断性16层CT进行了对比评估。慢转鹰眼系统的X射线管(S 23转/转)的剂量约为常规诊断成像所用诊断系统的三分之一。对图像重建进行了优化，以获得低噪声。高对比度的空间分辨率明显落后于诊断数据：鹰眼的MTF50和MTF10(MTF分别降至50%和10%的分辨率)的平均值为2.8+/-0.1厘米(-1)，DST(标准重建滤光片)的MTF50和MTF10的平均值为5.3+/-0.1厘米(-1)。在沙发移动方向(z坐标)的分辨率由固定的鹰眼切片宽度5 mm控制。重建精度被发现通过将默认z增量从4.4 mm减小到2.2 mm来提高。与在鹰眼剂量范围内运行的诊断系统相比，低对比度物体的可探测性更好。然而，在诊断剂量方案中，小的低对比度细节在DST中仍然可见，而鹰眼无法检测到。虽然不具备诊断质量，但低剂量鹰眼为SPECT衰减校正和解剖定位能力提供了适当的数据。
The 4-slice CT that forms part of the GE Infinia Hawkeye-4 SPECT-CT scanner (Hawkeye) is evaluated against the diagnostic 16-slice CT that is incorporated in the GE Discovery ST PET-CT system (DST). The x-ray tube of the slow-rotating-Hawkeye system (23 s/rotation) operates at approximately a third of the dose of diagnostic systems as used for conventional diagnostic imaging. Image reconstruction is optimized for low noise. High-contrast spatial resolution significantly falls behind diagnostic figures: the average of MTF50 and MTF10 (resolution where the MTF has fallen to 50% and 10%) is 2.8 +/- 0.1 cm(-1) for Hawkeye and 5.3 +/- 0.1 cm(-1) for the DST (standard reconstruction filters). Resolution in the direction of the couch movement (z coordinate) is governed by the fixed Hawkeye slice width of 5 mm. Reconstruction accuracy is found to be increased by reducing the default z increment from 4.4 mm to 2.2 mm. Low-contrast object detectability is superior compared with diagnostic systems operating in the Hawkeye dose range. In the diagnostic dose regime, however, small low-contrast details remain visible in DST that are not detectable with Hawkeye. Although not of diagnostic quality, the low-dose Hawkeye provides appropriate data for SPECT attenuation correction and anatomical localization capability.