Department of Nuclear Medicine, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
Eur J Nucl Med Mol Imaging. 2011 Apr;38(4):742-52. doi: 10.1007/s00259-010-1683-y. Epub 2010 Dec 10.
We investigated the performance of the Inveon small-animal PET/SPECT/CT system and compared the imaging capabilities of the SPECT and PET components.
For SPECT, the energy resolution, tomographic spatial resolution and system sensitivity were evaluated with a (99m)Tc solution using a single pinhole collimator. For PET, the spatial resolution, absolute sensitivity, scatter fraction and peak noise equivalent count were evaluated. Phantoms and a normal rat were scanned to compare the imaging capabilities of SPECT and PET.
The SPECT spatial resolution was 0.84 mm full-width at half-maximum (FWHM) at a radius of rotation of 25 mm using a 0.5-mm pinhole aperture collimator, while the PET spatial resolution was 1.63 mm FWHM at the centre. The SPECT system sensitivity at a radius of rotation of 25 mm was 35.3 cps/MBq (4 × 10(-3)%) using the 0.5-mm pinhole aperture, while the PET absolute sensitivity was 3.2% for 350-650 keV and 3.432 ns. Accordingly, the volume sensitivity of PET was three orders of magnitude higher than that of SPECT.
This integrated PET/SPECT/CT system showed high performance with excellent spatial resolution for SPECT and sensitivity for PET. Based on the tracer availability and system performance, SPECT and PET have complementary roles in multimodality small-animal imaging.
我们研究了 Inveon 小动物 PET/SPECT/CT 系统的性能，并比较了 SPECT 和 PET 组件的成像能力。
对于 SPECT，使用单孔准直器用（99m）Tc 溶液评估能量分辨率、断层空间分辨率和系统灵敏度。对于 PET，评估了空间分辨率、绝对灵敏度、散射分数和峰值噪声等效计数。使用 phantom 和正常大鼠进行扫描，以比较 SPECT 和 PET 的成像能力。
使用 0.5-mm 小孔孔径准直器，当旋转半径为 25mm 时，SPECT 空间分辨率为 0.84mm 半最大值全宽（FWHM），而 PET 空间分辨率为中心的 1.63mm FWHM。当旋转半径为 25mm 时，SPECT 系统灵敏度使用 0.5-mm 小孔孔径为 35.3cps/MBq（4×10(-3)％），而 PET 的绝对灵敏度为 350-650keV 的 3.2％和 3.432ns。因此，PET 的体积灵敏度比 SPECT 高三个数量级。
该集成的 PET/SPECT/CT 系统具有出色的 SPECT 空间分辨率和 PET 灵敏度，性能优异。基于示踪剂的可用性和系统性能，SPECT 和 PET 在小动物多模态成像中具有互补作用。
