癌细胞DNA含量测量中的图像处理研究
I
摘 要
近些年来,癌症患者的数量呈上升趋势,使得癌症及肿瘤科学的研究异常紧迫。
肿瘤细胞 DNA 含量的测定和分析对恶性肿瘤的早期病理诊断、恶性程度判定、疗
效估价和预测预后具有重要价值。传统的方法是采用流式细胞仪(Flow Cytometer),
虽然它有精确度高、速度快、检测细胞数量多和能进行细胞周期分析等优点,但
是细胞的形态特征在处理过程中会被丢失,且设备复杂,仪器价格昂贵,难以广
泛应用。而如果应用图像光度术(Image Cytometer)则不仅能对组织细胞切片上
极少量的细胞核作 DNA 含量测量和倍体分析,同时可以测量对诊断和预后判断都
极具价值的细胞核的某些形态参数。
应用图像光密度术检测病理切片时,病理切片细胞图像中的噪声、不均匀背景
和粘连细胞,将严重影响 DNA 含量测定和分析的准确性。因此,图像处理技术在
癌细胞 DNA 含量测量中有着十分重要的意义。
本文主要应用 ICM 方式来测定和分析肿瘤细胞的 DNA 含量,研究了如何从图
像处理的方面,如图像的去噪、分割、粘连细胞的分离、细胞的特征提取及 DNA
含量的计算等方面进行改进,提高肿瘤细胞 DNA 含量测定的正确性与效率。
在图像预处理中,本文首先介绍了图像二值化、图像去噪与图像增强的原理,
并提出了对于背景不均匀细胞图像的二值化方法。接着对比了三种自适应阈值分
割算法的分割效果及耗用时间,包括最佳阈值法、最大类间方差法和最佳熵阈值
法,选择出最适合本文癌细胞 DNA 染色图像的分割方法。最后,对已失去形态特
征意义的边缘细胞,应用了区域生长的方法进行边缘像素擦除。
在粘连细胞的分离中,本文首先简单描述了腐蚀膨胀算法和测地重建算法的
缺点。接着,详细阐述了分水岭算法的三种实现过程,指出对于形态异型性较大
的细胞显微图像中等值淹没更为合理,并在现有算法的基础上,提出了新的基于
地形图的等值跟踪算法,也就粘连分离效果及耗用时间对三种方法进行了性能比
较;同时,还详细描述了陆宗骐教授的链码差法的实现过程,提出了有效的凹点
配对原则――“相亲原则”,就性能与前三种分水岭实现方法进行了比较。最后简
单带过三种其它算法:矢量夹角法、估算圆心法和多边形近似法。
在细胞的特征提取中,本文首先从链码差法的粘连分离结果图像中,介绍了
单细胞的周长、圆心、面积和圆度的计算方法。之后,估算了现有图像中细胞的
DNA 含量。
II
关键词:DNA 含量 粘连分离 分水岭 链码跟踪 图像分割
III
ABSTRACT
Recently, the upward trend of the cancer patient number makes it necessary to
study on cancer and knub. Identification and analysis of DNA content in tumor cells
have great value on early pathological diagnose 、malignant degree estimation 、
treatment evaluation and prediction of malignant tumor. The traditional method is
using Flow Cytometer, which is precise, fast, can work on large scale and can analysis
cell cycle, but the morphological characters would be lost in the procedure, and the
complex and expensive equpiments also made this method hard to widely apply.
While Image Cytometer(ICM) can measure the DNA content of cell nucleus, analysis
the chromosome number based on farthing cells in tissue, further more it can measure
some morphological characters which are of great importance for diagnosing and of
prediction of cancer.
When using ICM to measure the pathology slice cell, the noise, non-uniform
background and adhesion cells on the image would seriously infect the correctness of
measurement and therefore the analysis of DNA content. Consequently, image process
technique has key important meaning on measurement of DNA content on cancer
cells.
This paper mainly uses ICM method to measure and analysis the DNA content of
cancer cells, studies the method to improve the correctness and efficiency through
image process, including denoise, partition, separation of adhesion cells, character
distill and DNA content calculation.
During the preprocess step, this paper firstly introduces the principle of image
thresholding, image denoising, and image enhancement. Then it raises a threshold
method to cell image with non-uniform background. Furthermore it compares the
threshold effect and time consuming of three adaptive threshold algorithms including
Best Threshold Method, Otsu Method and KSW Entropic Method, and chooses the
most appropriate threshold method to the cancer cell DNA chromatic image in this
paper. Finally, the edge cells that have lost the morphological significant is removed
by region growing method.
In the adhesion cells separation step, this paper simply describes the weakness of
Erosion Dilation Algorithm and Distance Image Reconstruction Method in the
beginning. Then it elaborates three achievements of Watershed Method, and indicates
IV
that for cell micro image with large morphological difference, it's more reasonable to
Equivalent submerge. Based on the existing algorithms, it raises a new Trace and
Mark Algorithm Based on Distance Transformation and compares the adhesion cell
separation efficiency and time consuming of three achievements. At the same time, it
describes the achievement on chain code difference by Professor Lu, Zongqi in detail,
which proposes the effective concave pair principle----Dating Principle, and also
compares its efficiency with other three achievements. Finally it briefly tells the other
three algorithms (Vector Angle Method, Circle Center Estimation Method, and
Optimal Polygon Approximation Method)
During the cell character distill step, this paper starts with adhesion cell
separation result image by Chain Code Difference Method, followed by introduction
the calculation method of perimeter, center, area, and roundness. Finally this paper
estimates the DNA content of the existing image cell.
Key word: DNA content; adhesion separation; watershed; code
tracing; image segmentation
V
目录
摘 要
ABSTRACT
第一章 绪论 ..............................................................................................................1
§1.1 课题背景 ....................................................................................................... 1
§1.2 DNA 含量测定的发展现状 ........................................................................... 1
§1.2.1 流式细胞术 ....................................................................................... 1
§1.2.2 图像细胞光度术 ............................................................................... 2
§1.3 课题选题意义和依据 ................................................................................... 3
§1.4 论文主要研究内容及结构 .......................................................................... 3
第二章 ICM 定量测定技术的基本原理 .................................................................. 4
§2.1 细胞的分裂周期 ........................................................................................... 4
§2.2 肿瘤 ............................................................................................................... 5
§2.3 DNA 含量测定原理 ....................................................................................... 5
§2.3 本章小结 ....................................................................................................... 7
第三章 图像的预处理 ..............................................................................................8
§3.1 图像的获取 ................................................................................................... 8
§3.1.1 标本处理 ............................................................................................ 8
§3.1.2 显微图像采集系统 ............................................................................ 8
§3.2 灰度直方图 .................................................................................................. 9
§3.3 自适应阈值分割 ........................................................................................ 10
§3.3.1 最佳阈值法 ...................................................................................... 11
§3.3.2 最大类间差法 .................................................................................. 12
§3.3.3 最佳熵阈值法(KSW 熵法) ............................................................... 13
§3.3.4 三种阈值分割方法比较 ................................................................. 14
§3.4 图像去噪与增强 ........................................................................................ 17
§3.4.1 图像的平滑 ...................................................................................... 17
§3.4.2 图像的锐化 ...................................................................................... 18
§3.5 擦除边缘细胞 ............................................................................................ 21
§3.5.1 区域生长 ......................................................................................... 21
§3.6 本章小结 ..................................................................................................... 22
第四章 细胞图像的粘连分离 ................................................................................24
§4.1 腐蚀膨胀法 ................................................................................................ 24
VI
§4.1.1 算法原理 ......................................................................................... 24
§4.1.2 算法优缺点 ..................................................................................... 25
§4.2 测地重建法 ................................................................................................ 26
§4.2.1 算法的原理 ..................................................................................... 26
§4.2.2 算法的优缺点 ................................................................................. 26
§4.3 分水岭法 ..................................................................................................... 27
§4.3.1 算法的原理 ...................................................................................... 27
§4.3.2 算法实现方法一 ............................................................................. 27
§4.3.3 算法实现方法二 ............................................................................. 31
§4.3.4 算法实现方法三 ............................................................................. 33
§4.3.5 三种实现方法比较 .......................................................................... 35
§4.4 链码差法 ..................................................................................................... 38
§4.4.1 算法的原理 ..................................................................................... 38
§4.4.2 算法的优缺点 ................................................................................. 44
§4.5 其它算法 .................................................................................................... 46
§4.5.1 矢量夹角法 ..................................................................................... 46
§4.5.2 估算圆心法 ..................................................................................... 47
§4.5.3 多边形近似法 ................................................................................. 47
§4.6 本章小结 ..................................................................................................... 48
第五章 癌细胞的特征提取 ....................................................................................50
§5.1 形态特征提取 ............................................................................................ 50
§5.1.1 周长 ................................................................................................. 51
§5.1.2 圆心 ................................................................................................. 51
§5.1.3 面积 ................................................................................................. 51
§5.1.4 圆度 ................................................................................................. 53
§5.2 DNA 含量统计分析 ..................................................................................... 53
§5.3 本章小结 .................................................................................................... 55
第六章 总结与展望 ................................................................................................56
总结 ..................................................................................................................... 56
展望 ..................................................................................................................... 57
参考文献 ..................................................................................................................... 58
在读期间公开发表的论文和承担科研项目及取得成果 ......................................... 61
致 谢 ......................................................................................................................... 62
第一章 绪论
1
第一章 绪论
§1.1 课题背景
成人的人体大概由 100 万亿个细胞构成,如果一个细胞在分裂时发生了异常,
就有可能形成肿瘤。肿瘤分为良性和恶性。恶性肿瘤,俗称癌,威胁着人类的健
康以至生命,它和脑血管病、心脏病在人类死亡原因中占前三位[1]。每年,恶性
肿瘤在全球致死 700 万人,我国也有 100 万人因此失去生命[2]。
肿瘤组织无论在细胞形态和组织结构上,都与其发源的正常组织有不同程度
的差异,这种差异称为异型性[3]。异型性是肿瘤异常分化在形态上的表现。区别
这种异型性的大小是诊断肿瘤,确定其良、恶性的主要组织学依据。良性肿瘤细
胞的异型性不明显,一般与其来源组织相似。恶性肿瘤常具有明显的异型性。表
现为肿瘤细胞的多形性,即肿瘤细
胞形态和大小不一致。还有肿瘤细胞核的多形性。肿瘤细胞核比正常细胞核
增大,核大小、形状和染色不一。并可出现双核、巨核、多核、奇异核、核着色
深(由于核内 DNA 增多)。恶性肿瘤细胞的核异常改变多与染色体呈多倍体或
非整数倍体有关。所以,肿瘤细胞 DNA 含量的测定和分析对恶性肿瘤的早期病
理诊断、恶性程度判定、疗效估价和预测预后具有重要价值。
§1.2 DNA 含量测定的发展现状
目前,国内外对于肿瘤细胞 DNA 含量的测定已经开始走向商用,主要测量
方式可分为两类:流式细胞术(Flow Cytometry,
FCM)和图像细胞光度术(Image
Cytometry,ICM)。
§1.2.1 流式细胞术
流式细胞术 (Flow Cytometry)是70 年代发展起来的一种利用流式细胞仪对
细胞等生物粒子的理化及生物学特性(细胞大小、DNA/RNA 含量、细胞表面抗
原表达等)进行定量、快速、客观多参数相关检测分析的新技术[4]。它借鉴了荧
光显微镜技术与血球计数原理,同时利用荧光染料、激光技术、单抗技术以及计
算机技术的发展,大大提高了检测速度与统计精确性,而且从同一个细胞中可以
同时测得多种参数,为生物医学与临床检验学发展提供了一个全新的视角和强有
摘要:
展开>>
收起<<
I摘要近些年来,癌症患者的数量呈上升趋势,使得癌症及肿瘤科学的研究异常紧迫。肿瘤细胞DNA含量的测定和分析对恶性肿瘤的早期病理诊断、恶性程度判定、疗效估价和预测预后具有重要价值。传统的方法是采用流式细胞仪(FlowCytometer),虽然它有精确度高、速度快、检测细胞数量多和能进行细胞周期分析等优点,但是细胞的形态特征在处理过程中会被丢失,且设备复杂,仪器价格昂贵,难以广泛应用。而如果应用图像光度术(ImageCytometer)则不仅能对组织细胞切片上极少量的细胞核作DNA含量测量和倍体分析,同时可以测量对诊断和预后判断都极具价值的细胞核的某些形态参数。应用图像光密度术检测病理切片时,病理...
相关推荐
-
跨境电商商业计划书模版VIP免费
2025-01-09 27 -
跨境电商方案范文VIP免费
2025-01-09 14 -
创业计划书VIP免费
2025-01-09 18 -
xx生鲜APP计划书VIP免费
2025-01-09 12 -
跨境电商创业园商业计划书(盈利模式)VIP免费
2025-01-09 8 -
跨境电商计划书VIP免费
2025-01-09 13 -
绿色食品电商平台项目计划书VIP免费
2025-01-09 22 -
农产品电子商务商业计划书VIP免费
2025-01-09 9 -
农村电商平台商业计划书VIP免费
2025-01-09 13 -
生鲜商城平台商业计划书VIP免费
2025-01-09 21
作者:侯斌
分类:高等教育资料
价格:15积分
属性:66 页
大小:2.61MB
格式:PDF
时间:2024-11-19

