摘要
为使人体对γ射线的衰减造成核医学影像的失真和定量误差得到校正 ,在用于发射成像的单光子发射断层扫描机 (SPECT)上安装偏置的线源和平行缝准直器 ,可以获得倾斜的扇形束透射投影。这项构想在三探头 SPECT系统上进行了实验 ,取得了清晰的透射投影。使用 3种方法重建出衰减系数分布图 ,证明倾斜扇形束投影作 36 0°扫描能解决数据截断的问题 。
Photon attenuation within the body causes the quantitative errors in a single photon emission tomography (SPECT) image. The attenuation map must be known for proper attenuation correction. A shifted line source and slice collimator were used to obtain oblique fan beam transmission projection data on a three detector SPECT system. Hi quality projection data were acquired, and 3D attenuation maps were reconstructed using three methods. The experiments show that 360 degree scanning can compensate projection truncation of an oblique fan beam and that a special analytic algorithm, convolution back projection reconstruction inferred for oblique fan beam projection, can accuralely reconstruct the 3D attenuation.
出处
《清华大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2000年第1期57-60,共4页
Journal of Tsinghua University(Science and Technology)
基金
国家自然科学基金项目! (396 70 2 2 7)
关键词
核医学
断层图像
图像重建
SPECT
人体透射图像
single photon emission tomcgraphy (SPECT)
oblique fan beam projection
image reconstruction
