Akiyama Y
Physics Section, Chiba Cancer Center Hospital.
Nihon Igaku Hoshasen Gakkai Zasshi. 1992 May 25;52(5):660-8.
A multislice fan beam collimator which has parallel collimation along the cephalic-caudal axis of a patient and converging collimation within planes that are perpendicular to that axis was designed for a SPECT system with a rotating scintillation camera, and it was constructed by the lead casting method which was developed in recent years. A reconstruction algorithm for fan beam SPECT was formed originally by combining the reconstruction algorithm of the parallel beam SPECT with that of the fan beam X-ray CT. The algorithm for fan beam SPECT was confirmed by means of computer simulation and a head phantom filled with diluted radionuclide. Not only 99mTc but also 131I was used as a radionuclide. A SPECT image with the fan beam collimator was compared with that of a parallel hole, low energy, high resolution collimator which was routinely used for clinical and research SPECT studies. Both system resolution and sensitivity of the fan beam collimator were approximately 20% better than those of the parallel hole collimator. Comparing SPECT images obtained from fan beam collimator with those of parallel hole collimator, the SPECT images using fan beam collimator had far better resolution. A fan beam collimator is a useful implement for the SPECT study.
一种多层扇形束准直器专为配备旋转闪烁相机的单光子发射计算机断层扫描（SPECT）系统而设计，该准直器在患者的头足轴方向上具有平行准直，而在垂直于该轴的平面内具有汇聚准直，并且它是通过近年来开发的铅铸造方法构建的。扇形束SPECT的重建算法最初是通过将平行束SPECT的重建算法与扇形束X射线计算机断层扫描（CT）的重建算法相结合而形成的。扇形束SPECT的算法通过计算机模拟和填充稀释放射性核素的头部模型得到了验证。不仅使用了99m锝（99mTc），还使用了131碘（131I）作为放射性核素。将带有扇形束准直器的SPECT图像与常用于临床和研究SPECT研究的平行孔、低能、高分辨率准直器的图像进行了比较。扇形束准直器的系统分辨率和灵敏度均比平行孔准直器高出约20%。将从扇形束准直器获得的SPECT图像与平行孔准直器的图像进行比较，使用扇形束准直器的SPECT图像具有更好的分辨率。扇形束准直器是SPECT研究的一种有用工具。
