提出了基于互信息的EAA(Extraction of Available Area有效区域提取)算法的配准方法。此方法根据人体脑部医学图像特点,首先通过图像的灰度差异,对图像进行预处理,并利用区域生长法,提取互信息的有效区域——病灶的可疑区域和颅骨轮廓,...提出了基于互信息的EAA(Extraction of Available Area有效区域提取)算法的配准方法。此方法根据人体脑部医学图像特点,首先通过图像的灰度差异,对图像进行预处理,并利用区域生长法,提取互信息的有效区域——病灶的可疑区域和颅骨轮廓,然后只将此区域做为配准的有效信息,寻找配准参数,使两幅图像的互信息最大。仿真时采用MR-PET图像,进行了22组对比实验。结果表明,此方法一定程度上消除了图像中无效区域的影响,在配准精度及配准时间上有一定的优势。展开更多
The quality of the radiation dose depends upon the gamma count rate of the radionuclide used. Any reduction in error in the count rate is reflected in the reduction in error in the activity and consequently on the qua...The quality of the radiation dose depends upon the gamma count rate of the radionuclide used. Any reduction in error in the count rate is reflected in the reduction in error in the activity and consequently on the quality of dose. All the efforts so far have been directed only to minimize the random errors in count rate by repetition. In the absence of probability distribution for the systematic errors, we propose to minimize these errors by estimating the upper and lower limits by the technique of determinant in equalities developed by us. Using the algorithm we have developed based on the tech- nique of determinant inequalities and the concept of maximization of mutual information (MI), we show how to process element by element of the covariance matrix to minimize the correlated systematic errors in the count rate of 113 mIn. The element wise processing of covariance matrix is so unique by our technique that it gives experimentalists enough maneuverability to mitigate different factors causing systematic errors in the count rate and consequently the activity of 113 mIn.展开更多
文摘提出了基于互信息的EAA(Extraction of Available Area有效区域提取)算法的配准方法。此方法根据人体脑部医学图像特点,首先通过图像的灰度差异,对图像进行预处理,并利用区域生长法,提取互信息的有效区域——病灶的可疑区域和颅骨轮廓,然后只将此区域做为配准的有效信息,寻找配准参数,使两幅图像的互信息最大。仿真时采用MR-PET图像,进行了22组对比实验。结果表明,此方法一定程度上消除了图像中无效区域的影响,在配准精度及配准时间上有一定的优势。
文摘相关性分析因其能快速发现数据间潜在的关系而变得越来越重要了.在现实生活中,人们经常要分析多变量间的相关性大小.鉴于此,提出一种能够度量多变量间相关关系的度量方法——多变量间的最大互信息系数(Multi-variable Maximal Mutual Information Coefficient, Mv_MMIC),该方法能够探测多变量间广泛的相关关系,这里的广泛相关关系包括线性和非线性的函数型关系,甚至所有的函数型关系.首先利用最大互信息系数MIC (Mutual Information Coefficient)构建最大互信息系数矩阵,然后基于矩阵的特征分解原理,利用最大互信息系数矩阵的特征值构建出度量多变量间相关关系的度量方法,把度量两个随机变量间的相关关系的方法MIC巧妙地从两纬度的度量准则推广到度量多变量间的相关性的多维度度量准则中,最后通过实验证明:多变量间的最大互信息系数Mv_MMIC保留了MIC的通用性和公平性的优点,具有一定的理论研究和实际应用价值.
文摘The quality of the radiation dose depends upon the gamma count rate of the radionuclide used. Any reduction in error in the count rate is reflected in the reduction in error in the activity and consequently on the quality of dose. All the efforts so far have been directed only to minimize the random errors in count rate by repetition. In the absence of probability distribution for the systematic errors, we propose to minimize these errors by estimating the upper and lower limits by the technique of determinant in equalities developed by us. Using the algorithm we have developed based on the tech- nique of determinant inequalities and the concept of maximization of mutual information (MI), we show how to process element by element of the covariance matrix to minimize the correlated systematic errors in the count rate of 113 mIn. The element wise processing of covariance matrix is so unique by our technique that it gives experimentalists enough maneuverability to mitigate different factors causing systematic errors in the count rate and consequently the activity of 113 mIn.
