基于灰度共生矩阵的大鼠肝细胞癌、肝硬化结节超顺磁性氧化铁MR增强图像纹理特征分析

目的 基于灰度共生矩阵分析大鼠肝细胞癌(HCC)结节及肝硬化超顺磁性氧化铁(SPIO)增强图像纹理特征.方法 建立大鼠HCC及肝硬化模型,获取大鼠HCC、肝硬化结节SPIO增强图像,手动选取161个(HCC结节81个,肝硬化80个)感兴趣区(ROI),通过生成灰度共生矩阵,提取两组图像的二阶矩、对比度、相关、逆差矩、熵、方差6种纹理特征参数,并进行统计学分析.结果 大鼠HCC结节呈相对均匀的高信号,较大HCC灶(>2 cm)呈高、低混杂信号,肝硬化结节在SPIO增强图像呈低信号.HCC组的相关及熵均值高于肝硬化组(P＜0.05),二阶矩、对比度、逆差矩及方差的均值低于肝硬化组(P＜0.05).结论 通过灰度共生矩阵提取的二阶矩、对比度、相关、逆差矩、熵、方差6种纹理特征参数,可进一步用于基于纹理特征的大鼠HCC、肝硬化结节SPIO增强图像的计算机辅助诊断.     

游程长度分析用于不同超声仪之间超声纹理定量测量的差异性研究

目的研究相同超声纹理在不同超声仪上获取的游程长度纹理测量值是否存在显著差异。方法 30例正常志愿者,男女各半,分别在两台不同超声仪的相同设置和不同设置条件下取右小腿外侧腓肠肌纵切面图像。用自行研制的软件,以32×32像素点的正方形取样框对所取图像中最典型的腓肠肌纹理进行取样,计算其游程长度纹理参数,用配对t检验检测相同设置和不同设置下两台超声仪上所取图像的纹理测值是否差异显著。结果配对t检验结果显示不同仪器相同设置和不同设置条件下配对的12个纹理参数中有9个存在显著性差异(P0.05)。结论不论在相同设置还是不同设置下,相同对象相同部位的腓肠肌超声纹理用不同的超声仪取图测量,游程长度测量的纹理测值大部有显著的差异,这也就是说在各种超声仪器上采集的图像用游程长度分析进行超声纹理的测量,所测值不能进行相互比较。     

胃粘膜下肿瘤超声内镜声像图的纹理分析价值

目的：研究多种纹理参数对胃粘膜下肿瘤超声内镜声像图综合分析的价值。方法：采用５种纹理参数（平均灰度差异、对比度、方差、斜度和峭度）对１８例胃粘膜下平滑肌瘤和１１例胃粘膜下平滑肌肉瘤的超声内镜声像图进行了检测和比较。结果：①设计出了适合超声内镜声像图分析的纹理参数软件；②两病种间平均灰度差异、对比度、方差和斜度等值均存在显著差异，而峭度值也存在差异，但差异不显著；③５种纹理参数值的变化与胃粘膜下肿瘤的声像图特征具有很大的相关性。结论：本文５种纹理参数对鉴别超声内镜胃粘膜下肿瘤的声像图性质有一定价值。     

基于T1WI增强的MR纹理分析评价胶质母细胞瘤MGMT启动子甲基化的研究

目的 本研究主要是分析O⁶-甲基鸟嘌呤-DNA甲基转移酶(MGMT)启动子甲基化状态与胶质母细胞瘤(GBM)磁共振纹理特征的相关性。方法 收集经本院病理诊断为GBM的患者128例，所有患者术前均行磁共振平扫及增强检查。利用3D Slicer软件提取4方面磁共振纹理特征，包括一阶数据、形态和形状、纹理：灰度共生矩阵、纹理：灰度运行长度矩阵。采用χ²检验分析MGMT启动子甲基化与GBM磁共振特征的关系；采用独立样本t检验以及Mann-Whitney U检验，分析MGMT启动子甲基化与磁共振纹理特征的关系。结果 MGMT启动子甲基化GBM与MGMT启动子未甲基化GBM的磁共振纹理特征相比较，有7种磁共振纹理特征差异显著(P<0.05)，分别是能量(P=0.033)、熵(P=0.032)、一致性(P=0.030)、自相关(P=0.035)、方差：灰度共生矩阵(P=0.031)、灰度不均匀性(P=0.029)、群集阴影(P=0.032)。结论 MGMT启动子甲基化GBM与MGMT启动子未甲基化GBM的磁共振纹理特征相比较，有7种磁共振纹理特征可以...     

基于游程长度分析的超声有向性纹理定量测量研究

目的基于游程长度分析的超声有向性纹理定量测量方法和技术细节基本确定后,了解典型的超声有向性纹理的正常值范围和彼此间的差异,并了解目前确立的纹理测量方法在超声有向性纹理定量测量中的准确性。方法本研究分正常神经组、骨骼肌组、乳腺腺体组三组,各组对象分别在规定体位及仪器条件下取神经、骨骼肌、乳腺腺体超声图像,用自行研制的软件、以64×64像素点的正方形取样框对所取图像中最典型的有向性纹理进行取样,计算其游程长度纹理参数,用单因素方差分析三组参数测值的差异。结果三组的参数中大部分有显著差异,其中4个纵横比参数(参数9~12)在三组间不仅差异显著(P0.05),而且参数的大小与实验前的设想一致。结论基于游程长度分析的超声有向性纹理定量测量方法,不仅能够准确地测量各种超声有向性纹理,而且能够将不同长短粗细的超声有向性纹理区分开。     

游程长度分析用于乳腺腺体横切面图像超声纹理定量测量的研究

目的规范应用游程长度分析测量乳腺腺体横切面超声纹理的方法,研究乳腺各个部位纹理参数的差异,估测乳腺腺体纹理参数的正常值范围。方法选择正常成年妇女30例,取每例双乳6个部位的乳腺腺体横切面超声图像,依据游程长度分析原理设计参数定量测量其纹理,采用方差分析对各部位的测值进行统计分析。结果各部位间乳腺腺体的纹理测值均无显著差别(P>0.05),将6个部位的纹理测值合并,计算每个参数的95%正常值范围。结论乳腺腺体超声纹理定量测量不必限制测量部位,参数95%正常值范围有参考价值。     

基于GRNN的HIFU治疗中生物组织变性自动识别方法

目的 探讨一种基于广义回归神经网络 (Generalized Regression Neural Network，GRNN)的高强度聚焦超声（High intensity focused ultrasound，HIFU）治疗所致生物组织变性的自动识别方法。方法 提取超声减影图像的灰度-梯度共生矩阵及灰度差分中18个特征参数，分别利用P值假设验证法、欧几里得距离（欧氏距离）判定法对特征参数进行二次选择，最后选取欧氏距离靠前的2个最佳特征参数随机组合输入GRNN进行生物组织变性自动识别。结果 分别结合GRNN的总识别率：一次筛选掉的平均值、对比度分比二次筛选时欧氏距离靠后的小梯度优势、能量低，二次筛选得到的灰度分布不均性、梯度分布不均匀性分别约91.18%、90.20%，2个最佳特征参数组合高达98.04%。结论 经筛选后的特征参数组合输入GRNN的总识别率显著提高。     

超声成像测量不同姿势下腓肠肌形态的信度

目的探讨肌肉骨骼超声测量站立位和俯卧位下人体腓肠肌内侧肌结构参数的信度,并比较不同姿势下腓肠肌内侧肌结构参数的差异。方法 2017年12月至2018年5月,由2名操作者使用肌肉骨骼超声分别获取健康青年人30例俯卧位和站立位右侧腓肠肌内侧肌超声图片,测量肌肉厚度、肌纤维长度和羽状角。3 d后由其中一名操作者使用同样的方法测量。计算组内相关系数(ICC)、测量标准误差(SEM)和最小可检测变化值(MDC),比较两种姿势下参数的差异。结果俯卧位下测试者间ICC=0.932～0.943,重测ICC=0.880～0.915;站立位下测试者间ICC=0.922～0.938,重测信度ICC=0.839～0.925。俯卧位和站立位下,肌肉厚度、肌纤维长度和羽状角有非常显著性差异(P 0.01)。站立位下测试者间SEM小于俯卧位,俯卧位下重测MDC小于站立位。结论超声测量站立位及俯卧位下腓肠肌内侧肌的结构参数具有良好的信度;腓肠肌形态学测量站立位更准确,俯卧位更敏感。     

MRI动态增强图像纹理分析在鉴别诊断乳腺良恶性肿瘤的应用价值

目的:探讨MRI动态增强图像纹理分析在鉴别诊断乳腺良恶性肿瘤的应用价值。方法:回顾性分析本院经手术病理证实的35例乳腺良性肿瘤与35例恶性肿瘤的MRI动态增强图像的影像及纹理特征。采用MaZda软件提取所有患者MRI动态增强图像中感兴趣区(ROI)的直方图与灰度游程矩阵特征参数,采用独立样本t检验(正态分布数据)或非参数检验Mann-WhitneyU检验(偏态分布数据)比较良恶性组间纹理参数的差异,提取差异有统计学意义的纹理参数,使用ROC曲线分析差异有统计学意义参数鉴别良恶性肿瘤的诊断效能,运用多变量logistic回归分析对差异有统计学意义的纹理参数进行建模并绘制ROC曲线评价模型效能。结果:直方图参数中的均值及第10、50、90、99百分位数与灰度游程矩阵参数中的游程长不均匀度(包括水平、垂直、45dgr、135dgr4个方向)在两组间的差异有统计学意义(P均<0.001),其中第99百分位数(Pere.99%)以239.50为阈值时诊断效能最佳;通过对差异有统计学意义的参数分别建立的多参数logistic回归诊断模型可以得出直方图参数的logistic回归诊断模型效能更佳。结论:乳腺MRI动态增强图像纹理分析鉴别诊断良恶性肿瘤具有良好的价值。     

腓肠肌羽状角的高频超声测量及其临床意义

目的 探讨正常人群腓肠肌及其亚部构筑的超声解剖学特点。方法应用高频超声对40名健康志愿者共80条腓肠肌肌腹及其远端肌肉腱膜处进行在体实时扫查,获得腓肠肌内、外侧头及其亚部超声图像：并在静息（分惯用脚和非惯用脚）及用力5kg、10kg等长收缩状态下获取腓肠肌内侧头和外侧头羽状角超声测值。采用单因素方差分析比较不同状态下腓肠肌羽状角测值的差异,采用成组t检验比较惯用脚与非惯用脚腓肠肌羽状角测值的差异。结果腓肠肌上部横断面扫查时,内、外侧头肌肉依据肌肉内强回声分隔,均可分为肌质亚部、浅亚部和深亚部3个部分,各部分边界清晰。外侧头3个亚部分隔呈侧卧姿的“T”形条状强回声,内侧头分隔则呈卧姿的“Y”形条状强回声,在“T”和“Y”字形强回声分隔上均可探及血流信号。腓肠肌外侧头远端羽状角为外侧浅亚部连接于跟腱构成,内侧头远端羽状角则为内侧肌质亚部续于跟腱构成。静息及用力5kg、10kg状态下,腓肠肌内侧头羽状角测值分别为（13．36±3．20）°、（13．32°±3．30）°、（12．75土3．20）°,外侧头羽状角测值分别为（8．69±3．30）°、（8．59±2．99）°、（8．65±3．20）°,同一状态下内侧头羽状角测值均大于外侧头羽状角测值,且差异有统计学意义（t值分别为9．09、9．50和8．10,P均〈0．01）。腓肠肌内、外侧头在静息及承受不同外力的状态下,羽状角变化均无统计学意义（F=0．89、0．02,P=O．41、0．98）。惯用脚与非惯用脚腓肠肌内侧头羽状角测值分别为（13．66±3．60）°（13．30±2．84）°,腓肠肌外侧头羽状角测值分别为（8．71±3．48）°、（8．80±3．35）°。惯用脚肠肌内侧头羽状角测值大于非惯用脚,而腓肠肌外侧头羽状角测值小于非惯用脚,但差异均无统计学意义（t=O．70、0．87,P=O．48、0．17）。结论在体高频超声可清晰显示腓肠肌内、外侧头及其亚部构筑的超声解剖特点,并可获取羽状角的准确测值。     

Variation and reliability of ultrasonographic quantification of the architecture of the medial gastrocnemius muscle in young children

The aim of this study was to evaluate the suitability of ultrasonography for the quantification of gastrocnemius muscle architecture in healthy young children. The variation and reliability of measurement of muscle thickness, pennation angle and fibre length of the medial gastrocnemius were determined, using stationary and portable ultrasound machines, in 13 boys and eight girls aged 4–10. Ultrasound images were obtained from each leg, in duplicate, with the ankle at 90°, then at maximal plantar flexion, with the two machines within the same session. The same set of 16 scans was repeated in four children 4–6 weeks later. The mean muscle thickness, pennation angle and fibre length differed between ankle positions and between legs. Measurements obtained using the two machines established similar values with no significant differences in absolute values and coefficients of variation (CV). For duplicate images taken during the same session for the same leg, ankle position and machine, the CV and intraclass correlation coefficients (ICC) ranged, respectively, from 2·1% to 3·1% and 0·94–0·98 for muscle thickness, from 4·1% to 6·0% and 0·85–0·96 for pennation angle and from 4·5% to 6·3% and 0·87–0·96 for fibre length. Corresponding values for variables for the same child measured on two separate occasions were within the same ranges, all being similar to reliability data reported previously for adult muscle. Muscle thickness, pennation angle and fibre length of the medial gastrocnemius can therefore be quantified reliably, using either a stationary or portable ultrasound machine, in healthy young children.     

Effects of instrument adjustments on quantitative echocardiographic gray level texture measures.

Quantitative echocardiographic gray level texture measures have proved useful in characterizing a variety of cardiac abnormalities, including contusion, ischemia, and cardiomyopathies. However, alterations of echocardiographic signal processing controls could potentially affect the resulting data. The purpose of this study was to assess the effect of common echocardiographic instrument adjustments on texture data. We imaged a graphite-in-gel phantom on five separate occasions, each time using 12 combinations of adjustments of transmit power, compression, and postprocessing curves over a clinically applicable range. Image texture was assessed using gray level run length and gray level difference texture measures; 42 individual measures were calculated. Significance of texture measure variations was assessed by analysis of variance. Changes in all three controls were associated with significant alterations in texture measures. Adjustments of transmit power and compression produced larger changes in texture measures than did adjustments of postprocessing curves. There were significant transmission-compression-postprocessing interaction effects (p less than 0.05) for all but eight of the texture measures. For each texture measure, there were significant transmission-compression interaction effects (p less than 0.05). In summary, instrument adjustments had significant effects on quantitative texture measures, and these effects should be considered when evaluating quantitative echocardiographic gray level texture measures.     

Muscle Composition Analysis of Ultrasound Images: A Narrative Review of Texture Analysis

Skeletal muscle composition, often characterized by the degree of intramuscular adipose tissue, deteriorates with aging and disease and contributes to impairments in function and metabolism. Ultrasound can provide surrogate measures of muscle composition through measurement of echo intensity; however, there are several limitations associated with its analysis. More complex image processing features, broadly known as texture analysis, can also provide surrogates of muscle composition and may circumvent some of the limitations associated with muscle echo intensity. Here, texture features from the intensity histogram, gray-level co-occurrence matrix, run-length matrix, local binary pattern, blob analysis, texture anisotropy index and wavelet analysis are discussed. The purpose of this review was to provide a conceptual understanding of texture analysis as it pertains to muscle composition of ultrasound images.     

基于MR图像三维纹理特征的阿尔茨海默病和轻度认知障碍的分类

目的 利用三维纹理特征对阿尔茨海默病(AD)患者和轻度认知障碍(MCI)患者进行分类识别,以探索AD早期诊断新途径。方法 对12例早期AD患者(AD组)、12例MCI患者(MCI组)及12名健康对照者(NC组)的MR图像进行三维纹理分析,采用灰度共生矩阵和游程长矩阵提取每位受试者左、右侧海马结构及胼胝体的三维纹理特征,选取三组间存在显著性差异的纹理参数作为特征变量,采用支持向量机(SVM)方法对各组进行分类,利用留一法估算分类准确率。结果 对NC组与MCI组、MCI组与AD组、NC组与AD组进行分类识别的最高准确率分别为79.17%、83.33%、91.67%。结论 利用三维纹理分析可分类识别早期AD患者及MCI患者,有助于AD的早期诊断。     

Medial Gastrocnemius Muscle–Tendon Junction and Fascicle Lengthening across the Range of Motion Analyzed in 2-D and 3-D Ultrasound Images

Ultrasound imaging modalities offer a clinically viable method to visualize musculoskeletal structures. However, proper data comparison between investigations is compromised because of a lack of measurement error documentation and method standardization. This investigation analyzes the reliability and validity of extracting medial gastrocnemius belly and fascicle lengths and pennation angles in different ankle joint positions, across the full range of motion, in a cohort of 11 children with spastic cerebral palsy and 11 typically developed children. Each of these parameters was extracted from two consecutive acquisitions, using both 2-D and 3-D ultrasound images. The findings suggest that the muscle tendon junction extraction in 2-D images can be a suitable parameter for analyzing medial gastrocnemius muscle length in typically developed children and children with spastic cerebral palsy, although averaging over multiple measurements is recommended to reduce variability. More caution should be taken when performing analyses based on fascicle length.     

Associations between muscle structure and contractile performance in seniors

Background

Changes in muscle structure due to aging occur in a process known as sarcopenia. These changes can alter muscle mechanics during contraction that may limit mobility in seniors. The purpose of this study was to investigate the effect of sarcopenia on muscle fascicle length, pennation and belly thickness in a contracting muscle during isokinetic movements. Fascicles within a pennate muscle shorten at a slower velocity than that of the muscle belly, in a process called belly gearing. Belly gearing may be affected by atrophy and so was also tested in these seniors.

Methods

The gastrocnemii were tested using ultrasound from 10 young adults (20–40 years) and 9 seniors (70–85 years). The muscle structure was imaged during standing and maximal plantarflexion at four constant velocities on a dynamometer and torque, position and time were recorded during contractions.

Findings

The muscle belly thickness and pennation in seniors were significantly lower than young adults during standing. Belly thickness, changes in pennation, the belly gearing, ankle torque and power output were all significantly lower in seniors during plantarflexion contractions of the medial gastrocnemius (MG) and lateral gastrocnemius (LG).

Interpretation

The higher pennation observed in young adults is commonly associated with increased fascicle rotations during contraction causing an increased belly gearing. The decreased fascicle rotations in seniors resulted in reduced belly gearing but the size of this effect did not match the loss in strength or power from the muscles.     

基于T2WI图像纹理分析评价大鼠心肺复苏后脑损伤初步研究

目的:探讨基于T2WI图像纹理分析评价大鼠心肺复苏（CPR）后脑损伤的可行性。方法:将18只SD大鼠随机（随机数字法）分为假手术组（ n=8）及模型组（ n=10）。模型组大鼠恢复自主循环（ROSC）6 h后行T2WI序列扫描,假手术组于术后6 h扫描。比较两组大鼠基于T2WI图像的纹理特征及AQP4及和NSE抗体免疫组织化学评分的差表达异。运用受试者工作特征曲线(ROC)评价两组间差异的纹理特征对脑损伤的诊断效能。运用Spearman等级相关系数分析两组间差异的纹理特征与免疫组织化学AQP4及NSE抗体表达之间的相关性。 结果:两组的最小强度值、标准偏差、差分熵、逆差矩及高灰度不均匀性特征的差异具有统计学意义（ P<0.05）模型组大鼠全脑T2WI纹理特征的最小强度值、标准偏差及逆差矩明显低于假手术组（ P<0.05）,而差分熵及高灰度不均匀性显著高于假手术组（ P<0.05）。差分熵诊断效能最优,ROC曲线下面积（area under curve, AUC）为0.922,敏感度100%及特异度75%。模型组AQP4及NSE表达免疫组织化学（AQP4及NSE）评分明显著高于假手术组（ P<0.05）。最小强度值与AQP4及NSE抗体表达均呈正相关( r=0.501、0.568, P=0.048、0.022);标准偏差与AQP4及NSE抗体表达均呈正相关( r=0.620、0.530, P=0.010、0.035);差分熵与AQP4抗体表达呈负相关( r=-0.535, P=0.033)。 结论:基于T2WI图像的纹理分析可以评估脑水肿及神经元受损情况程度,最小强度值、标准偏差、和差分熵是反映评估心脏骤停CPR后脑损伤程度的敏感指标,其中差分熵敏感度和特异度最高。     

3.0T磁共振T1WI对比增强图像纹理分析鉴别眼眶淋巴瘤与炎性假瘤

目的:探讨纹理分析在鉴别眼眶淋巴瘤与炎性假瘤中的价值。方法:纳入经手术病理证实的眼眶淋巴瘤25例和炎性假瘤24例,使用MaZda软件提取T 1WI对比增强(contrast-enhanced T 1-weighted images,CE-T 1W)肿瘤纹理特征。比较两组游程长矩阵(run-length matrix,RLM)的20个纹理特征参数,对差异有统计意义的参数进行主成分分析(principal component analysis,PCA)。采用多变量logistic回归模型分别对在两组间差异有统计学意义的特征参数及主成分进行建模,绘制受试者工作特征曲线(receiver operating characteristic curve,ROC)以评价模型效能。结果:淋巴瘤组灰度不均匀度(grey level non-uniformity,GLNU)、长游程优势(long run emphasis,LRE)的4个参数高于炎性假瘤(P<0.001),短游程因子(short run emphasis,SRE)、游程图像分数(fraction of image in runs,FIR)的4个参数低于炎性假瘤组(P<0.001);游程长不均匀度(run length non-uniformity,RLNU)的4个参数在两组间差异无统计学意义(P>0.05)。在两组间差异有统计学意义的参数中,以GLNU的参数建立的多变量logistic回归模型的诊断效能最高,灵敏度、特异度及曲线下面积(area under curve,AUC)分别为95.9%、72.0%、0.905;PCA提取出的2个主成分建立的多变量logistic回归模型的灵敏度、特异度及AUC分别为87.5%、88.0%、0.913。结论:基于CE-T 1W的RLM特征可有效鉴别眼眶淋巴瘤与炎性假瘤,其中以GLNU的诊断效能最高。     

乳腺X线图像纹理特征预测乳腺癌腋窝淋巴结转移

目的 探讨乳腺X线图像纹理特征预测乳腺癌腋窝淋巴结转移的价值。方法 回顾性分析171例病理证实为非特殊类型浸润性乳腺癌患者的X线及临床资料。所有患者均接受腋窝淋巴结清扫手术,并根据手术及病理结果将患者分为腋窝淋巴结转移组和非转移组。分析患者的X线头尾位图像纹理特征,应用灰度直方图及灰度共生矩阵纹理分析方法测定均值、标准偏差、偏度、峰度、方差、能量、熵、自相关、惯量、逆差距和反差等11个纹理参数。结果 171例患者中淋巴结转移组96例,非转移组75例。X线检出腋窝淋巴结阴性119例,阳性52例,其诊断腋窝淋巴结转移的敏感度和特异度分别为48.96%（47/96）和93.33%（70/75）。X线图像纹理分析结果显示腋窝淋巴结转移组能量、熵、逆差距、自相关值均高于非转移组,惯量、反差值均低于非转移组（P均< 0.05）;其余纹理特征参数值两组间差异无统计学意义（P均> 0.05）。纹理参数值能量、熵、惯量、逆差距、自相关和反差诊断腋窝淋巴结转移的ROC曲线下面积（AUC）值分别为0.610、0.610、0.374、0.599、0.612和0.421（P均< 0.05）。乳腺X线检查、纹理特征及X线联合纹理特征诊断腋窝淋巴结转移的AUC值分别为0.711、0.676和0.787（P均< 0.05）;纹理特征、乳腺X线联合纹理特征诊断腋窝淋巴结转移的敏感度分别为62.5%和64.6%,特异度分别为66.7%和82.7%。结论 乳腺X线图像纹理参数对腋窝淋巴结转移有一定的预测作用,且乳腺X线联合纹理特征可提高对腋窝淋巴结转移的诊断效能。