【摘要】 为了评估准直器特性,并优化准直器设计,对单光子发射断层成像(SPECT)系统的投影过程进行了分析。从Shannon信息论的角度,建立发射断层成像系统投影过程中信息迁移机制的模型,以评估投影数据的完备性。将Shannon信息论应用到SPECT成像领域,根据在SPECT系统中信息量、条件熵、互信息熵的意义,提出了评估投影数据完备性的原理和方法。通过对平行孔准直器系统的计算验证了评估算法,并对4组编码孔径准直器进行了模拟。结果表明,该方法可以用来分析SPECT系统的准直器特性,根据物理条件来选取最佳的准直器设计。更多还原

【Abstract】 The projection stage of single photon emission computed tomography(SPECT) was analyzed to evaluate the collimator characteristics and optimize the collimator design.An information transmission model for the SPECT imaging system was developed based on Shannon’s information theory to evaluate the projection data integrity.Shannon’s information theory was also applied to the SPECT imaging field.The physics was evaluated to analyze the conditional entropy and the mutual information.The evaluation methodology was validated by simulations of a parallel hole collimator system with four types of coded aperture collimators.The results demonstrate that the methodology can be used to analyze the collimator characteristics and optimize collimator design according to given physical conditions.更多还原