A Bayesian approach to subvoxel tissue classification in NMR microscopic images of trabecular bone

NMR microscopy is currently being used as an investigational tool for the evaluation of micromorphometric parameters of trabecular bone as a possible means to assess its strength. Since, typically, the image voxel size is not significantly smaller than individual trabecular elements, partial volume blurring can be a major complication for accurate tissue classification. In this paper, a Bayesian segmentation technique is reported that achieves improved subvoxel tissue classification. Each voxel is subdivided either into eight subvoxels twice the original resolution, or up to four subvoxels along the transaxial direction and the subvoxels optimally classified as either bone or marrow. Based on a statistical model for partial volume blurring, the likelihood for the number of marrow subvoxels in each voxel can be computed on the basis of its measured signal. To resolve the ambiguity of the location of the marrow subvoxels, a Gibbs distribution is introduced to model the interaction between the subvoxels. Neighboring subvoxel pairs with the same tissue label are encouraged, and pairs with distinct labels are penalized. The segmentation is achieved by maximizing the a posteriori probability of the label image using the block ICM (iterative conditional mode) algorithm. The potential of the proposed technique is demonstrated in real and synthetic NMR microscopic images.     

红细胞沉降率IV──红细胞沉降速度测量的原理和方法

本文从理论上提出了红细胞沉降速度的准确概念，阐明了红细胞沉降过程所包含的物理和生理信息，提出了一种新型测量红细胞沉降速度及其它特征参数的方法，并给出了其主体、硬件和软件设计要点。     

Electroretinograms (ERGs) and visual-evoked potentials (VEPs) elicited by pattern displacement.

The relation between the amplitude of visual responses to a checkerboard stimulus and the degree of lateral displacement of the checks was examined across different check sizes with simultaneously recorded electroretinograms (ERGs) and visual-evoked potentials (VEPs). The amplitudes of both the b-wave and the after-potential of the ERG increase linearly with pattern displacement. However, the major components of the VEP (N70 and P100) were smaller than expected from linearity for both small checks with small displacements (thresholding) and for large checks with large displacements (saturation). These results suggest that the ERG is proportional to the number of receptors stimulated, but the VEP reflects neural processes influenced by the spatial structure of the stimulus.     

医学司法鉴定中精神病患者反复上访原因分析

目的 了解司法鉴定中精神病患者反复上访原因。方法 对诊断为无精神病者与诊断为精神病偏执型人格障碍、偏执性精神病、精神分裂症者的上访诱因、动机、目的、内容、时间、形式、有否过激行为等进行比较。结果 上访诱因、动机、目的等方面以生活、工作、经济问题为主；上访时间以患病5—20a者居多。共33例(71．73％)：上访者中有过激行为者21例(45．65％)。结论 精神病患者上访者中以偏执型人格障碍、偏执性精神病、精神分裂症居多。其特点与正常人有所区别。这就要求政府部门在接待上访者及处理上访问题时。应加以严格区分并正确、合理解决上访要求。以免产生不良的社会问题。     

辐照氟银猪皮的实验研究

报道辐照氟银猪皮的制备、实验检测（弹性、创面粘附力和透水性测定，含银量测定）组织学检查细菌检测及抑菌试验研究，结果表明：辐照氟银猪皮除延伸度低于未辐照猪皮外，其撕裂强度、创面粘合力和透水性均与未辐照猪皮相似。组织学检查示：辐照氟银猪皮组织结构完整，表皮细胞部分空泡形成。组织细菌检测证明其无菌生长，达到无菌要求。抑菌试验证明对金黄色葡萄球菌、绿脓杆菌、大肠杆菌、变形杆菌、克雷伯氏菌均有极强的抑菌作用     

Optimal metabolite curve fitting for kinetic modeling of 11C-WAY-100635.

Many quantitative imaging protocols that make use of a metabolite-corrected arterial input function require the use of a mathematic model to describe the rate of metabolism of the radioligand. Commonly, parametric models are fit to metabolism data and then the fitted model is used to correct the plasma input function. (11)C-WAY 100635 is a rapidly metabolized radioligand used extensively in mapping the 5-hydroxytryptamine receptor 1A system. METHODS: To evaluate the adequacy of fit of 4 metabolite models, we examined data from 92 subjects who received an injection of (11)C-WAY 100635, were imaged with PET, and underwent measurement of total plasma concentration and metabolites. The performance of these models was assessed according to residual plots, as well as fit and information criteria. RESULTS: The study showed that the choice of model has a substantial effect on the resulting estimates of outcome measures. CONCLUSION: Among the models considered, the Hill model provides the best fit across all criteria.