School of Allied Health Sciences, Kitasato University, 1-15-1 Kitasato, Sagamihara, Kanagawa, 228-8555, Japan.
Ann Nucl Med. 2010 Jun;24(5):427-32. doi: 10.1007/s12149-010-0350-5. Epub 2010 Feb 23.
Radioactive sources for evaluating sensitivity and uncertainty in the radioactivity measurements performed using PET scanners must be equipped with absorber materials that ensure the annihilation of positrons. Attenuation and scattering owing to the absorber materials produce uncertainty in the performance evaluation. The aim of this study is to propose a point-like radioactive source with multiple absorber capsules, for which evaluation can be independent of scatter and attenuation owing to the source absorbers.
The point-like source consists of a small spherical radioactive part and a set of successively sized cylindrical aluminum absorber capsules. Data were collected for different total absorber thicknesses. By an extrapolation technique, the effects of the source absorbers were eliminated. Sensitivity and uncertainty in the radioactivity measurements of PET scanners were evaluated with this technique.
Sensitivity and uncertainty of radioactivity measurement to the point-like radioactive source were evaluated successfully with this method.
The proposed point-like radioactive source is useful for evaluating performance characteristics of PET scanners in a way that is independent of the effects of the source absorbers.
用于评估正电子发射断层扫描（PET）扫描仪进行放射性测量的灵敏度和不确定度的放射性源必须配备吸收材料，以确保正电子的湮没。由于吸收材料的衰减和散射会导致性能评估出现不确定度。本研究的目的是提出一种具有多个吸收器胶囊的点状放射性源，其评估可以独立于源吸收器的散射和衰减。
点状源由一个小的球形放射性部分和一组尺寸依次递增的圆柱形铝吸收器胶囊组成。为不同的总吸收器厚度收集数据。通过外推技术，消除了源吸收器的影响。利用该技术评估了 PET 扫描仪的放射性测量的灵敏度和不确定性。
该方法成功地评估了点状放射性源对放射性测量的灵敏度和不确定性。
所提出的点状放射性源可用于以独立于源吸收器影响的方式评估 PET 扫描仪的性能特性。
