Automatic Liver Segmentation Method Based on Three Views of CT Image

针对肝脏分割结果中出现的误分割问题,在分析腹部CT图像序列中肝脏结构特性和成像特点的基础上,充分利用肝脏灰度特性和结构特性的互补信息,提出一种组合三视图分割结果的置信连接肝脏自动分割方法。从各视图的最佳角度提取肝脏轮廓线,将其合并得到最终的肝脏轮廓,有效减少了肝脏与相邻器官灰度相似性造成的误分割现象,进一步提高了肝脏自动分割的准确率。对10套腹部CT数据集的实验结果表明,该方法能够快速、准确的提取肝脏轮廓,为临床肝病诊断和手术计划制定提供有效的个体化信息。In order to solve the problem of misclassification in liver segmentation process, an automatic confidence connected liver segmentation method with a combination of the liver segmentation results of three views was proposed.Based on the analysis of liver structure and its imaging features on CT images, this method took full advantage of the liver intensity specialty and shape specialty.The final liver boundary is the combination of the contours extract from best angle of each view.The misclassifications caused by the gray similarity of liver and adjacent organs were reduced.The accuracy of automatic liver segmentation was improved.Clinical validation was performed on 10 abdominal CT data-sets.The results show that the proposed method can extract liver contour quickly and accurately.And it is useful for clinical liver diagnosis and surgery planning.国家自然科学基金(61102137;61327001); 河南省科技厅重点科技攻关计划项目(142102310298); 河南省教育厅科学技术研究重点项目基础研究(14A520056); 南阳师范学院专项项目(ZX2013012

Research on Living Liver Image Registration and Its Application

肝脏是人体重要的消化器官，肝脏疾病直接影响人的健康和生存。随着医学、计算机技术及生物医学工程技术的发展，医学影像学为临床诊断提供了多种模式的医学图像，这些图像在医学诊断和治疗中的作用显得非常重要。但是单一模式的图像往往不能提供医生所需要的足够的诊断信息。在实际临床应用中，往往需要将不同模式的医学图像有机地结合起来，得到更丰富的信息以便了解病变组织或器官的综合信息，从而做出准确的诊断或制订出合适的治疗方案，这就首先寻找一种(或一系列)空间变换，使两幅图像的对应点达到空间位置和解剖结构上的完全一致即进行图像配准。配准结果应使两幅图像上所有的解剖点，或至少是所有具有诊断意义的点都达到匹配。由于在体肝...Liver is one of the most important organs in human. With the development of the medicine and computer technique, more and more modals medical images have emerged. Modern medical research usually requires integrated analysis of multiple images to get more information. A fundamental problem in medical image integrated analysis is that the images should be perfectly aligned, one essential aspect ther...学位：工学博士院系专业：信息科学与技术学院通信工程系_通信与信息系统学号：B20043000

广义量词理论的渊源及其发展趋势

介绍广义量词理论的发展简史;论述广义量词理论的基本思想、方法和优势,给出了广义量词的语义解释方法和语义类型;总结广义量词理论的三个主要研究方向。广义量词理论注重广义量词的语义和推理特征的研究,它比一阶逻辑具有更强大的表达力。广义量词理论为计算机科学中的知识表示和知识推理注入了新的活力。教育部人文社科研究规划项目“面向自然语言信息处理的广义量词理论研究”(12YJA72040001

Variation Type Analysis of Hepatic Duct Based on CT Image

在术前预现肝脏管道结构,分析管道分支的变异情况,能降低活体肝脏移植手术过程的风险。以肝脏管道系统包含的肝静脉、肝动脉与门静脉的主要分支变异类型为理论依据,在实现这三种肝脏管道三维重建的基础上,针对不同的结构特征,使用基于长度和阈值的方法分别设计相应的算法分析其分支变异类型。Preoperative display of hepatic duct structure and analysis of the variation of duct branches enables to reduce the operation risk of living liver transplantation. Taking the variation types of major branches of hepatic vein, hepatic artery and portal vein included in the hepatic duct system as the theoretical basis, after finishing the three-dimensional reconstruction of these three hepatic ducts, it uses methods relying on length and threshold to respectively design the corresponding algorithm analysis and branch variation types by targeting different structure features.国家自然科学基金资助项目(60371012,60601025);; 卫生部联合基金资助项目(WKJ2005-2-001)~

An Improved Fuzzy Connected Image Segmentation Method Base on CUDA

已有的模糊连接并行算法CUDA-k FOE未考虑线程块边缘点同时更新所引发的竞争问题,导致计算结果出现少量误差.由于医学图像处理对精度的要求很高,为了解决边缘点计算误差的问题,基于CUDA-k FOE提出一种修正迭代算法.首先分析了CUDA-k FOE算法在线程块边缘产生竞争的原因;然后讨论了边缘点亲和力的所有可能的传递路径,以及由此造成的出错情况;最后提出二次迭代修正算法,将第一次迭代得到的所有边缘点转入第二次的修正迭代步骤,从而修正第一次迭代中错误的亲和力值.采用3组不同规格的CT序列对肝脏血管进行分割实验,并选用3个不同的种子点进行算法验证,结果表明,文中算法的计算结果与串行版本一致,解决了CUDA-k FOE算法的计算误差问题.A paralleled CUDA version of k FOE(CUDA-k FOE)was proposed to segment medical images. CUDA-k FOE achieves fast segmentation when processing large image datasets. However, it cannot precisely handle the competition of edge points when update operations happen by multiple threads simultaneously, thus an iterative correction method to improve CUDA-k FOE was proposed. By analyzing all the pathways of marginal voxels affinity and their consequently caused results, a two iteration correction scheme is employed to achieve the accurate calculation. In these two iterations, the resulted marginal voxels from the first iteration are used as the correction input of the second iteration, therefore, the values of affinity are corrected in the second iteration. Experiments are conducted on three CT image sequences of liver vessels with small, medium, and large size. By choosing three different seed points, final results are not only comparable to the sequential implementation of fuzzy connected image segmentation algorithm on CPU, but achieve more precise calculation compared with CUDA-k FOE.国家自然科学基金(61001144;61102137;61301010;61327001

Directional region growing algorithm and its applications in vessel segmentation

针对医学图像中微细管道结构灰度连续性差,采用常规区域生长法进行分割容易丢失末梢的问题,提出一种定向区域生长算法,可以在生长过程中跨越管道结构中的低灰度区域。算法向图像中已生长区域外灰度最高的方向进行生长,每次将一个体素加入已生长区域,将图像转变为一颗以种子点为根结点的树,再从叶子结点进行回溯以确定感兴趣区域。对实现算法的数据结构进行了讨论。算法可以应用于任意维的图像。对2维和3维图像的测试结果表明,相对于常规的区域生长法,算法可以分割出更多的血管分支。算法对3维图像的运行时间为秒钟量级,可以满足临床应用的要求。Accurate extraction of the vasculature in medical images is prerequisite to structural analysis and further applications such as surgical planning.Region growing algorithm is a simple and effective method to extract thick blood vessels which makes use of the spatial continuity of the vascular tree,while the extraction result of small vessels like hepatic artery is unacceptable.In order to solve the problem that the continuity of tenuous vasculature is poor in medical images and vessel segmentation based on traditional region growing may lose distal branches,a directional region growing(DRG) algorithm is proposed which can skip the low gray area in the vasculature during the growing process.The algorithm grows towards the direction of the maximum gray around the grown region,and adds one voxel to the grown region in each iteration.The image is transformed into a tree after the growing process in which the seed point is the root.A trace back procedure beginning from the leaf nodes of the tree can finally determine the region of interest(ROI).The algorithm relaxes the conditions to determine ROI,and small area with low gray in the ROI is permitted.There are two time-consuming steps in the algorithm due to the enormous amount of data in 3D medical images,one is to determine the growing direction in each iteration,the other is to construct the paths from the seed point to leaf nodes during the trace back procedure.Data structure to improve the speed of the algorithm is discussed.The algorithm can be applied to images with any dimension.The algorithm is tested with 2D and 3D images.In both conditions,the segmentation results obtained by DRG contain more distal branches in comparison with traditional region growing algorithm.To some vein phase CT images with poor quality,the proposed algorithm can also generate better results.Four parameters should be appointed in the algorithm and the empirical values are given.The computational time of the algorithm on 3D images is several seconds,which is acceptable in clinical applications.The surface of the extracted vasculature is rough due to the discrete nature of digital images,and further study is needed to smooth the surface before visualization.国家自然科学基金项目(60701022;30770561

心房颤动患者左心耳功能及血流动力学计算机建模仿真的研究进展

心房颤动(简称房颤)是临床常见的心律失常,发病率高,且患病率随年龄增加而逐渐升高。发生房颤的原因包括冠状动脉心脏病、风湿性心脏病二尖瓣狭窄、甲状腺功能亢进等,还有一些不明原因的特发性房颤。房颤最常见同时也是最严重的并发症是左心房尤其是左心耳附壁血栓脱落后引起的血栓栓塞,由此导致的缺血性脑卒中是房颤患者致

Numerical modeling and biomechanical analysis of the human mitral valve

目的建立人体心脏二尖瓣仿真模型,模拟二尖瓣闭合的工作过程,分析二尖瓣各组件应力分布,探讨二尖瓣瓣叶和腱索的相互作用,并探寻腱索受力大小与腱索粗细之间的相关性。方法构建二尖瓣几何模型,在此基础上定义模型单元类型、材料属性、接触、载荷及约束,建立有限元模型,计算模型的应力、速度和位移等参数。结果瓣膜上的应力分布不均匀,后瓣叶亚区之间的裂口位置所受应力最大;不考虑腱索连接至瓣叶时,瓣叶负载后外翻至心房一侧;考虑腱索连接至瓣叶时,前、后瓣叶关闭良好;各腱索受力不同,与前瓣叶相连的支持腱索受力最大,腱索受力大小与腱索粗细之间的线性相关系数为0.954。结论瓣叶中心和后瓣叶亚区之间的裂口两处应力较大区域是临床上二尖瓣裂的常发生部位;与瓣叶相连的腱索可在瓣叶负载时,施加牵拉力使瓣叶不致发生翻转,前、后瓣叶恰好关闭;解剖结构粗壮的腱索受力较大。Objective To establish a numerical model of human mitral valve and simulate its closing process,so as to analyze stress distributions on the valve apparatuses,study the interaction between leaflets of mitral valve and chordae tendineae,and explore the relationship between the force of chordae tendineae and their thickness.Methods A geometric model of human mitral valve was constructed.On the basis of the geometric model,the finite element model was established by defining the element type,material attributes,contacts,loads and constraints.Parameters such as stress,velocity and displacement were calculated after solving the model.Results The stress distribution on the valve was non-uniform.The clefts between the scallops in the posterior leaflet were always under the highest load.When no chordae tendineae were attached,the leaflets turned over to the side of the atrium.When chordea tendineae were attached,the anterior and posterior leaflet could close up successfully.Different chordae tendineae applied different forces to the valve.The strut chorea tendineae attached to the anterior leaflet applied highest force among all the chordea tendineae.The correlation coefficient between the thickness of chordae tendineae and their force was 0.954.Conclusions The two zones with higher stresses,namely the center of the leaflet and the clefts between the three scallops in the posterior leaflet,are also the positions of mitral valve cleft in clinic.Chordea tendineae can apply the pulling force on the leaflets while the mitral valve is under load,thus the leaflets won't turn over to the side of atrium and the valve can close up in time.Chordea tendineae with thicker anatomic structure always apply a higher force on the leaflets.国家自然科学基金资助项目(61102137); 福建省自然科学基金资助项目(2011J01366); 福建省创新医学科研基金(2009-CXB-59

血流感染的耐碳青霉烯类鲍曼不动杆菌的分子机制及临床研究

目的探讨血流感染的耐碳青霉烯类鲍曼不动杆菌（CRAB）耐药机制,分析菌株同源性及患者的临床特征,为CRAB的感染控制提供实验依据。方法采用Bact/Alert 3D全自动血培养系统进行血培养,细菌鉴定和药敏使用Vitek-2 Compact全自动微生物分析系统。对2010年6月—2016年5月临床血流感染患者分离到的27株碳青霉烯类药物（亚胺培南和/或美罗培南MIC≥16μg/m L）耐药的CRAB复苏菌株,重新采用Vitek-MS质谱分析仪鉴定,采用改良Hodge试验检测碳青霉烯酶,PCR法检测B类酶基因(blaNDM、blaIMP和blaVIM)和D类酶基因(blaOXA-23、blaOXA-24、blaOXA-51和blaOXA-58)并测序比对。采用MALDI-TOF分析菌株同源性,并分析患者的临床资料及感染相关信息。结果血流感染的CRAB绝大多数对常用抗生素耐药。27株CRAB改良Hodge试验均阳性。所有CRAB均未检测到B类酶基因(blaNDM、blaIMP和blaVIM);25株CRAB同时检测到blaOXA-23和blaOXA-51;另2株CRAB则为blaOXA-58阳性。采用Vitek-MS进行同源性分析,细菌分成3大簇（Ⅰ型13株、Ⅱ型12株、Ⅲ型2株）。85.2%（25/27）患者来自重症监护病房或专科的监护病床,原发感染灶以肺部炎症最常见（11例）。所有的患者在血培养出CRAB前的30d内均有抗菌药物使用史,使用频率较高的抗菌药物有:碳青霉烯类、氟喹诺酮类、头霉素类。15例CRAB血流感染患者死亡。结论厦门地区的CRAB以D类产碳青霉烯酶OXA-23和OXA-51最为多见。CRAB血流感染的原发感染多为肺部炎症。福建省卫生联合资金面上项目(No.2016J01643

茶多酚及茶多酚锗的组成、结构和抑制肺癌细胞生长速率的研究

采用有机合成法合成茶多酚-锗化合物.运用反相液相色谱技术初步分离茶多酚和茶多酚锗的酚类组成.选用基质辅助激光解吸电离化飞行时间(MALDI-TOF)质谱技术分析茶多酚及茶多酚-锗的组成和结构.结果表明,茶多酚主要由儿茶素及酚类化合物组成,其中(-)表没食子儿茶素没食子酸酯(EGCG)、(-)表没食子儿茶素没食子棓酸甲酯(EGC-MG)和表三羟基黄烷-3-醇没食子酸酯(EZG)易与Ge4+反应且形成含锗的酚类化合物.茶多酚及茶多酚-锗化合物均有抑制肺癌细胞生长的能力,其抑制速率随着酚类化合物浓度增加而提高,但茶多酚锗抑制速率高于茶多酚近1倍