链码跟踪算法在三维医学图像处理中的应用

针对链码跟踪八方向寻址提出了一种新的链码跟踪算法，并将此方法运用于医学图像的等剂量线绘制当中。该算法将链码分为四个象限，依据不同的跟踪顺序加以连接，并遵循整体方向一致的原则。在得到一个封闭的轮廓信息后，再转向下一个轮廓，直到所有轮廓跟踪完毕，解决了医学图像处理中同一剂量的等剂量线出现多次的情况。将排序后的链码进行插值拟合，把x、y的关系转化为距离分别与x和y的关系，得到封闭的平滑的等剂量线。在医学图像处理的三维重建中利用此方法，得到的等剂量线效果较好。     

病变细胞显微图像分析与识别技术的研究

依据病变细胞的形态和颜色特征,我们提出了一种基于RGB和HIS彩色空间的自适应自动阈值分割算法,该算法能有效地将病变细胞的胞核从复杂的背景中提取出来.在分割图像的基础上,应用canny边缘检测算法提取出细胞边缘,采用八链码跟踪技术提取出细胞的特征值.为了同正常细胞比较,同时提取了正常细胞的特征值,并提出了二步识别算法以对正常和病变细胞进行识别.实验结果表明,该系统能有效地分割血细胞图像并且诊断率较高.     

WZX中医舌色分析系统的设计与实现

WZX中医舌色分析系统整个程序在WinXp,VC6.0环境下编译实现。CDib类选用《VC .Net图像处理编程》所附类库。WZX中医舌色分析系统功能包括:基本功能(显示、对比、历史记录等)、主要功能(舌体图像提取、舌象区域分割、色度测量等)。文章对WZX中医舌色分析系统功能实现中的一些技术问题进行了探讨。     

基于特征点的人体红外图像自动分割技术

目的医学红外人体图像区域分割是大规模医学红外图像处理的关键步骤。为快速有效地获取医学红外图像中的人体信息,本文提出一种在医学红外图像中自动提取并划分人体区域的方法。方法由红外热像仪在静室中采集人的裸体红外图像,然后通过对红外人体图像灰度分布特征分析而取得的阈值来获取人体区域,以人体横向距离(宽度)函数结合人体红外图像中的特殊方向亮带的识别,提取人体的特征点,并通过特征点对人体区域进行分割。结果对来自8人的72幅图像进行验证,其中64幅可以正确分割,证明该方法可以对直立姿势的红外人体图像进行自动区域分割与提取。结论该红外人体图像区域自动分割算法可为基于红外图像的疾病筛查及计算机辅助诊断提供技术基础。     

利用Contourlet变换进行双源CT图像中的二尖瓣分割

目的 利用双源CT图像对心脏二尖瓣瓣膜进行了增强与分割,为日后进行二尖瓣三维重建和运动分析提供基础。方法 提出了自适应种子填充法和Contourlet小波变换分别用于不同情况下的分割：首先用自适应种子填充法对双源CT胸腔图像进行心脏在造影剂下的区域分割,再用Contourlet小波变换对区域分割后的图像进行二尖瓣的增强和分割。结果 在MATLAB7.0的环境下对双源CT图像成功进行了处理和分割,获取了清晰的心脏二尖瓣图像。结论 本文提出的分割方法对不同情况下的分割非常有效,实验的结论对医生从事二尖瓣瓣膜运动研究和二尖瓣瓣膜外科手术规划提供有益的参考。     

基于BP-遗传算法优化的超声肿块区域分割技术

通过超声肿块区域分割处理,提高肿块检测诊断能力。提出一种基于BP-遗传算法优化的超声肿块区域分割技术。采用超声成像技术进行肿块图像采集,对采集的超声肿块图像进行块区域模板匹配处理,构建超声肿块区域检测模型,采用自适应模板特征匹配方法进行超声肿块图像融合处理,提取超声肿块区域图像的超像素特征量,根据像素特征差异度匹配方法实现超声肿块图像的关联相似度分解,以显著性特征点为中心进行超声肿块图像的区域重构,采用BP-遗传算法进行图像区域分割的自适应学习,实现超声肿块图像的高分辨辨识和分割。仿真结果表明,采用该方法进行超声肿块区域分割的精度较高,图像特征匹配性能较好,肿块区域的辨识度较高。     

用于癌加热疗法的含4％(重量比)硅的镍热源的发展

铁磁合金作为外科植入热源被发展和使用,在癌生长中的确定位置感应生热。由于含4％(重量比)硅的镍合金在所希望的45～60℃范围有居里温度,所以被用于此研究。使用特殊的浇铸技术或浇铸、锻压后匀质过程制备热源。本文讨论了不同的处理过程对这些合金的影响,特别指出了熔炼和热处理过程中使其氧化最小的重要性,以及在近居里温度热源均匀化对相对导磁性的影响。最好的处理工艺     

基于GVFSnake模型的图像分割方法在放射吸收法（RA）中的应用

目的:探讨GVFSnake模型在放射吸收法骨密度测定图像分割方面的价值.方法:本文将GVF Snake模型应用于目标区域分割,并与区域分割法进行对比.结果:实验表明梯度矢量流模型有较好的鲁棒性和实用性,分割结果与实际边界非常吻合.结论:GVF Snake模型为一种很实用的分割方法,能够应用在放射吸收法骨密度测定中.     

基于K-means聚类与改进随机游走算法的冠脉光学相干断层图像斑块分割

光学相干断层成像技术(OCT)现已发展成为国内外较热门的冠状动脉内影像技术,其中冠脉OCT图像的斑块区域分割对易损斑块的识别和研究有着重大意义。本文提出了一种基于K-means聚类与改进随机游走的新算法,实现了对冠脉钙化、纤维化斑块和脂质池的半自动化分割。本文主要创新点为改进了随机游走算法的权函数,将图像中像素间的边与种子点之间的距离加入到了权函数定义中,增加了弱边界的权值,防止了过分割现象的发生。本文基于以上方法对9名冠状动脉粥样硬化患者的OCT图像进行了斑块区域分割。通过对比医生手动分割结果,证明了本文方法具有良好的精度和鲁棒性,以期本文方法可对冠心病的临床诊断起到一定的辅助作用。     

硬脂酸和组织脱蜡透明液替代二甲苯在病理制片中的应用

目前绝大多数病理切片的制作仍延用传统的石蜡切片制作技术.病理制片过程中,组织的透明和切片染色前后的脱蜡、透明三个环节,普遍采用二甲苯作为透明、脱蜡剂.二甲苯属有毒物质,其毒性主要是对中枢神经和植物神经的麻醉及粘膜的刺激作用[1],且二甲苯在组织处理过程中,易使组织收缩、硬化变脆[2],对切片质量有一定影响.为此,我们通过反复试验,对传统石蜡病理制片方法进行了改良,应用无毒性的硬脂酸和组织脱蜡透明液完全替代二甲苯,取得了良好的制片效果,并有效避免了二甲苯对人体的危害及对环境的污染.     

基于活动轮廓模型的彩色白细胞图像自动分割方法研究

为解决血液白细胞显微图像自动识别中的图像分割问题,提出了一种基于活动轮廓的彩色白细胞图像自动分割方法,首先在Hue,Saturation,Intensitv（HSI）彩色空间中运用聚类分割得到细胞核,从而得到细胞所在的位置,然后用流域算法得到细胞大致的轮廓,最后将此轮廓作为初始轮廓,用梯度矢量流（GVF）外力及来自全局信息的区域力驱动,结合彩色信息,使得轮廓收敛于真实的细胞边界。实验结果表明,此方法能精确、有效地分割出单个以及部分重叠白细胞区域。     

Identification of the breast boundary in mammograms using active contour models

A method for the identification of the breast boundary in mammograms is presented. The method can be used in the preprocessing stage of a system for computeraided diagnosis (CAD) of breast cancer and also in the reduction of image file size in picture archiving and communication system applications. The method started with modification of the contrast of the original image. A binarisation procedure was then applied to the image, and the chain-code algorithm was used to find an approximate breast contour. Finally, the identification of the true breast boundary was performed by using the approximate contour as the input to an active contour model algorithm specially tailored for this purpose. After demarcation of the breast boundary, all artifacts outside the breast region were eliminated. The method was applied to 84 medio-lateral oblique mammograms from the Mini-MIAS database. Evaluation of the detected breast boundary was performed based upon the percentage of false-positive and false-negative pixels determined by a quantitative comparison between the contours identified by a radiologist and those identified by the proposed method. The average false positive and false negative rates were 0.41% and 0.58%, respectively. The two radiologists who evaluated the results considered the segmentation results to be acceptable for CAD purposes.     

大鼠下丘脑及邻近区域催产素免疫阳性神经元与垂体后叶的关系

本文运用免疫细胞化学PAP及ABC法,显示大白鼠下丘脑内OXT免疫阳性神经元,并于垂体后叶注射WGA-HRP,显示下丘脑中逆行标记细胞,结合免疫细胞化学方法,观察下丘脑及其邻近区域内HRP与OXT双标记细胞,证实下丘脑视上核、室旁核、穹窿前核和后核、血管周细胞群、下丘脑视前区、下丘脑前区及外侧区、背侧副细胞群内、室周部、第三脑室侧壁室管膜细胞下及室间孔部室管膜细胞下,均有OXT免疫阳性神经元,其中至少部分神经元可发出向垂体后叶的投射纤维。位于第三脑室侧壁室管膜下及室间孔部室管膜下的神经元,可能监测脑脊液中各种因素的变化,调节垂体后叶OXT的分泌,也可能直接通过共树突向脑脊液内释放OXT。     

Tracing functionally identified neurones in a multisynaptic pathway in the hamster and rat using herpes simplex virus expressing green fluorescent protein

Using a genetically modified herpes simplex virus encoding green fluorescent protein we sought to establish if this viral modification could be used in transneuronal tracing studies of the sympathetic nervous system. The herpes simplex virus encoding green fluorescent protein was injected into the adrenal medulla of three hamsters and six rats. After a suitable survival period, neurones in the sympathetic intermediolateral cell column of the thoracolumbar spinal cord, rostral ventral medulla and paraventricular nucleus of the hypothalamus were clearly identified by the presence of a green fluorescence in the cytoplasm of the neurones of both species. Thus, herpes simplex virus encoding green fluorescent protein labelled chains of sympathetic neurones in the hamster and rat and therefore has the potential to be used in transneuronal tracing studies of autonomic pathways in these species.     

Application of form features in digital cell analysis of non-Hodgkin''s lymphomas

The form of a biological cell nucleus can be characterized by the well-known circularity factor, which is derived from the area of an object and its circumference. More sophisticated form features are introduced, which are calculated from the curvature of an object (“bending energy”) or from invariant moments. To investigate the sensitivity of the various form features on controlled changes of form and the behaviour under rotation and scaling, algebraic curves similar to the form of real nucleus profiles are generated. Analysis of the shape characteristics of biological cells requires an extraction of the boundaries of the nuclei. This was performed by an edge detection algorithm using eight gradient masks followed by a contour tracing procedure with feedback. The suitability of the introduced form features for classification of different nucleus profiles on non-Hodgkin's lymphomas (NHL) was tested using a Bayes classifier.     

Organization of amygdaloid projections to the prefrontal cortex and associated striatum in the rat.

The organization of connections between the amygdala, prefrontal cortex and striatum was studied using anterograde and retrograde tract tracing techniques in the rat. The anterograde transport of Phaseolus vulgaris leucoagglutinin and wheat germ agglutinin conjugated to horseradish peroxidase was used to examine the striatal projections of the prefrontal cortex. These studies revealed that the prelimbic area of the medial prefrontal cortex projects mainly to the medial part of the striatum, whereas the dorsal agranular insular area of the lateral prefrontal cortex projects mainly to the ventrolateral part of the striatum. The organization of amygdaloid projections to the prefrontal cortex and its associated portions of the striatum was investigated using the fluorescence retrograde tract tracing technique. Different color fluorescent dyes, True Blue and Diamidino Yellow, were injected into the prefrontal cortex and striatum. These studies demonstrated that medial portions of the basolateral nucleus, and adjacent portions of the lateral, basomedial and amygdalo-hippocampal nuclei, project to both the medial prefrontal cortex and its associated medial striatal region. The rostral pole and lateral portions of the basolateral nucleus project to both the lateral prefrontal cortex and its associated lateral striatal region. Many neurons in the basolateral amygdaloid nucleus, and to a lesser extent other amygdaloid nuclei, were double-labeled in these experiments, indicating that these cells send collaterals to both the prefrontal cortex and striatum. These findings indicate that discrete areas of the amygdala, and in some cases individual amygdaloid neurons, can modulate information processing in the first two links of distinct cortico-striato-pallidal systems arising in the medial and lateral prefrontal cortex.     

The electrophysiological correlate of contour integration is similar for color and luminance mechanisms

Contour integration perceptually links together similarly oriented line elements hidden between randomly oriented distracters. To investigate how contour integration depends on early sensory processing, we compared the electrophysiological correlate of contour integration of elements defined by luminance (black-and-white) or isoluminant color (red-and-green) contrasts. Detection performance for color- and luminance-defined contours (both open and closed) was matched. Detectable contours elicited a negative shift over posterior electrodes starting 220 ms after stimulus onset. The shift occurred for both color and luminance contrasts, even when possible luminance artifacts in red-and-green stimuli were masked. This indicates a common physiological processing stream for orientation-based contour integration of red-and-green and black-and-white elements.     

基于神经元颜色拮抗与动态编码的轮廓检测方法

基于神经元的颜色拮抗特性及神经元群体的动态编码机制,实现对图像的轮廓检测。模拟视皮层下神经元的颜色单拮抗特性,引入单拮抗感受野的动态调节机制,以充分响应颜色边界和亮度边界;利用单细胞的树突极性分布,构建初级视皮层的双拮抗神经元网络,实现对特定方位的视觉刺激响应,有效提取目标轮廓;在神经元的群体感受野内,考虑神经元的动态突触连接,融合单细胞的脉冲频率响应,实现对纹理信息的抑制作用。以BSDS500图库的图像为实验对象,结果显示该方法在提取主体轮廓的过程中能有效抑制纹理信息,其对100幅图像最佳检测结果的P值指标均值和标准差为0.58±0.04,相对CORF和CO等其他对比方法,可提高轮廓提取的准确率。所提出方法可有效实现图像的轮廓检测,为利用颜色信息以及神经元之间的动态编码、实现更高级皮层的图像理解或者视觉认知提供新的思路。     

Serotonergic innervation of mesencephalic trigeminal nucleus neurons: a light and electron microscopic study in the rat

Neurons of the mesencephalic trigeminal nucleus (MTN) are considered to be homologous to mechanosensitive neurons in the sensory ganglia. The sites of origin of serotonin (5HT)-immunoreactive axons on neuronal cell bodies in the MTN were studied in the rat by combining immunofluorescence histochemical techniques with retrograde tracing of Fluoro-Gold (FG) and anterograde tracing of biotin-conjugated dextran amine (BDA). The tracing studies, which were combined with multiple-labeling immunohistochemistry and confocal microscopy, indicated that 5HT-immunoreactive axon terminals on the cell bodies of MTN neurons originated from the medullary raphe nuclei, such as the nucleus raphes magmus (RMg), alpha part of the nucleus reticularis gigantocellularis (GiA) and nucleus raphes obscurus (ROb), as well as from the mesopontine raphe nuclei, such as the nucleus raphes dorsalis (DR), nucleus raphes pontis (PnR) and nucleus raphes medianus (MnR); mainly from the RMg, GiA and DR, and additionally from the ROb, PnR and MnR. The cell bodies in close apposition to 5HT-immunoreactive axon terminals were found through the whole rostrocaudal extent of the MTN. Electron microscopically a number of axon terminals that were labeled with BDA injected into the raphe nuclei were confirmed to be in asymmetric synaptic contact with the cell bodies of MTN neurons. It was also indicated that substance P existed in some of the 5HT-containing axosomatic terminals arising from the ROb, RMg and GiA. The present results indicated that proprioceptive sensory signals from the muscle spindles or periodontal ligament might be modulated at the level of the primary afferent cell bodies in the MTN by 5HT-containing axons from the mesopontine and medullary raphe nuclei including the GiA.     

The spatial transformation of color in the primary visual cortex of the macaque monkey

Perceptually, color is used to discriminate objects by hue and to identify color boundaries. The primate retina and the lateral geniculate nucleus (LGN) have cell populations sensitive to color modulation, but the role of the primary visual cortex (V1) in color signal processing is uncertain. We re-evaluated color processing in V1 by studying single-neuron responses to luminance and to equiluminant color patterns equated for cone contrast. Many neurons respond robustly to both equiluminant color and luminance modulation (color-luminance cells). Also, there are neurons that prefer luminance (luminance cells), and a few neurons that prefer color (color cells). Surprisingly, most color-luminance cells are spatial-frequency tuned, with approximately equal selectivity for chromatic and achromatic patterns. Therefore, V1 retains the color sensitivity provided by the LGN, and adds spatial selectivity for color boundaries.