segmentation

分割
  • 文章类型: Journal Article
    结核病(TB)仍然是一种重要的全球性传染病,构成相当大的健康威胁,特别是在资源有限的地区。由于不同的数据集,放射科医生在使用X射线图像准确诊断结核病方面面临挑战。本研究旨在提出一种利用图像处理技术的创新方法,以在医疗保健的自动分割和分类(AuSC)框架内提高结核病诊断的准确性。
    结核病检测的AuSC(AuSC-DTB)框架包括几个步骤:涉及大小调整和中值滤波的图像预处理,使用随机步行算法进行分割,利用局部二值模式和梯度描述符直方图进行特征提取。然后使用支持向量机分类器对提取的特征进行分类,以区分健康和感染的胸部X射线图像。使用四个不同的数据集评估了所提出技术的有效性,如日本放射技术学会(JSRT),蒙哥马利,国家医学图书馆(NLM)和深圳。
    实验结果表明有希望的结果,准确率为94%,95%,95%,JSRT实现了93%,蒙哥马利,NLM,和深圳数据集,分别。与最近研究的比较分析表明,所提出的混合方法具有出色的性能。
    在AuSC框架内提出的混合方法展示了从不同X射线图像数据集进行TB检测的改进的诊断准确性。此外,这种方法有望推广通过X射线成像诊断的其他疾病.它可以适应计算机断层扫描和磁共振成像图像,扩展其在医疗保健诊断中的适用性。
    UNASSIGNED: Tuberculosis (TB) remains a significant global infectious disease, posing a considerable health threat, particularly in resource-constrained regions. Due to diverse datasets, radiologists face challenges in accurately diagnosing TB using X-ray images. This study aims to propose an innovative approach leveraging image processing techniques to enhance TB diagnostic accuracy within the automatic segmentation and classification (AuSC) framework for healthcare.
    UNASSIGNED: The AuSC of detection of TB (AuSC-DTB) framework comprises several steps: image preprocessing involving resizing and median filtering, segmentation using the random walker algorithm, and feature extraction utilizing local binary pattern and histogram of gradient descriptors. The extracted features are then classified using the support vector machine classifier to distinguish between healthy and infected chest X-ray images. The effectiveness of the proposed technique was evaluated using four distinct datasets, such as Japanese Society of Radiological Technology (JSRT), Montgomery, National Library of Medicine (NLM), and Shenzhen.
    UNASSIGNED: Experimental results demonstrate promising outcomes, with accuracy rates of 94%, 95%, 95%, and 93% achieved for JSRT, Montgomery, NLM, and Shenzhen datasets, respectively. Comparative analysis against recent studies indicates superior performance of the proposed hybrid approach.
    UNASSIGNED: The presented hybrid approach within the AuSC framework showcases improved diagnostic accuracy for TB detection from diverse X-ray image datasets. Furthermore, this methodology holds promise for generalizing other diseases diagnosed through X-ray imaging. It can be adapted with computed tomography scans and magnetic resonance imaging images, extending its applicability in healthcare diagnostics.
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  • 文章类型: Journal Article
    医学成像数据集经常遇到数据不平衡问题,其中大多数像素对应于健康区域,少数人属于受影响地区。像素的这种不均匀分布加剧了与计算机辅助诊断相关的挑战。用不平衡数据训练的网络往往表现出对多数类的偏见,往往表现出高精度,但灵敏度低。
    我们设计了一种基于对抗学习的新网络,即条件对比生成对抗网络(CCGAN),以解决高度不平衡的MRI数据集中的类不平衡问题。所提出的模型有三个新的组成部分:(1)特定类别的关注,(2)区域再平衡模块(RRM)和监督对比学习网络(SCoLN)。特定于班级的注意力集中在输入表示的更具区别性的区域,捕获更多相关特征。RRM促进了跨输入表示的各个区域的特征的更平衡的分布,确保更公平的细分过程。CCGAN的生成器通过基于真负图和真正图接收来自SCoLN的反馈来学习像素级分割。此过程确保最终的语义分割不仅解决了不平衡的数据问题,而且还提高了分类准确性。
    所提出的模型在五个高度不平衡的医学图像分割数据集上显示了最先进的性能。因此,该模型在医学诊断中具有巨大的应用潜力,在数据分布高度不平衡的情况下。CCGAN在各种数据集上的骰子相似系数(DSC)得分最高:BUS2017为0.965±0.012,DDTI为0.896±0.091,对于LiTSMICCAI2017,为0.786±0.046,对于ATLAS数据集,为0.712±1.5,和0.877±1.2的BRATS2015数据集。DeepLab-V3紧随其后,BUS2017的DSC评分为0.948±0.010,DDTI的DSC评分为0.895±0.014,对于LiTSMICCAI2017,为0.763±0.044,对于ATLAS数据集,为0.696±1.1,和0.846±1.4的BRATS2015数据集。
    UNASSIGNED: Medical imaging datasets frequently encounter a data imbalance issue, where the majority of pixels correspond to healthy regions, and the minority belong to affected regions. This uneven distribution of pixels exacerbates the challenges associated with computer-aided diagnosis. The networks trained with imbalanced data tends to exhibit bias toward majority classes, often demonstrate high precision but low sensitivity.
    UNASSIGNED: We have designed a new network based on adversarial learning namely conditional contrastive generative adversarial network (CCGAN) to tackle the problem of class imbalancing in a highly imbalancing MRI dataset. The proposed model has three new components: (1) class-specific attention, (2) region rebalancing module (RRM) and supervised contrastive-based learning network (SCoLN). The class-specific attention focuses on more discriminative areas of the input representation, capturing more relevant features. The RRM promotes a more balanced distribution of features across various regions of the input representation, ensuring a more equitable segmentation process. The generator of the CCGAN learns pixel-level segmentation by receiving feedback from the SCoLN based on the true negative and true positive maps. This process ensures that final semantic segmentation not only addresses imbalanced data issues but also enhances classification accuracy.
    UNASSIGNED: The proposed model has shown state-of-art-performance on five highly imbalance medical image segmentation datasets. Therefore, the suggested model holds significant potential for application in medical diagnosis, in cases characterized by highly imbalanced data distributions. The CCGAN achieved the highest scores in terms of dice similarity coefficient (DSC) on various datasets: 0.965 ± 0.012 for BUS2017, 0.896 ± 0.091 for DDTI, 0.786 ± 0.046 for LiTS MICCAI 2017, 0.712 ± 1.5 for the ATLAS dataset, and 0.877 ± 1.2 for the BRATS 2015 dataset. DeepLab-V3 follows closely, securing the second-best position with DSC scores of 0.948 ± 0.010 for BUS2017, 0.895 ± 0.014 for DDTI, 0.763 ± 0.044 for LiTS MICCAI 2017, 0.696 ± 1.1 for the ATLAS dataset, and 0.846 ± 1.4 for the BRATS 2015 dataset.
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  • 文章类型: Journal Article
    为了研究植物器官,有必要研究植物的三维(3D)结构。近年来,通过计算机断层扫描(CT)进行的无损测量已用于了解植物的3D结构。在这项研究中,我们以菊花小头花序为例,重点研究了3D小头花序芽结构中容器和小花之间的接触点,以研究小花在容器上的3D排列。要确定接触点的3D顺序,我们从CT体积数据构建了切片图像,并检测了图像中的容器和小花。然而,因为每个CT样本都包含数百个待处理的切片图像,每个C.seticuspe头花序都包含几个小花,手动检测容器和小花是劳动密集型的。因此,利用图像识别技术,提出了一种基于CT切片图像的接触点自动检测方法。所提出的方法使用接触点仅存在于插座周围的先验知识来提高接触点检测的准确性。此外,检测结果的积分使得能够估计接触点的3D位置。根据实验结果,我们证实了所提出的方法可以高精度地检测切片图像上的接触,并通过聚类估计它们的3D位置。此外,与样本无关的实验表明,所提出的方法达到了与样本相关实验相同的检测精度。
    To study plant organs, it is necessary to investigate the three-dimensional (3D) structures of plants. In recent years, non-destructive measurements through computed tomography (CT) have been used to understand the 3D structures of plants. In this study, we use the Chrysanthemum seticuspe capitulum inflorescence as an example and focus on contact points between the receptacles and florets within the 3D capitulum inflorescence bud structure to investigate the 3D arrangement of the florets on the receptacle. To determine the 3D order of the contact points, we constructed slice images from the CT volume data and detected the receptacles and florets in the image. However, because each CT sample comprises hundreds of slice images to be processed and each C. seticuspe capitulum inflorescence comprises several florets, manually detecting the receptacles and florets is labor-intensive. Therefore, we propose an automatic contact point detection method based on CT slice images using image recognition techniques. The proposed method improves the accuracy of contact point detection using prior knowledge that contact points exist only around the receptacle. In addition, the integration of the detection results enables the estimation of the 3D position of the contact points. According to the experimental results, we confirmed that the proposed method can detect contacts on slice images with high accuracy and estimate their 3D positions through clustering. Additionally, the sample-independent experiments showed that the proposed method achieved the same detection accuracy as sample-dependent experiments.
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  • 文章类型: Journal Article
    准确,自动地分割目标和危险器官(OAR)对于在线自适应放射治疗(ART)的成功临床应用至关重要。锥束计算机断层扫描(CBCT)自动分割的当前方法面临挑战,导致分割通常无法达到临床可接受性。当前的CBCT自动分割方法忽略了从初始规划和先前的自适应分数中获得的大量信息,这些信息可以提高分割精度。
    我们引入了一个新颖的框架,该框架结合了来自患者初始计划和先前适应性分数的数据,利用这个额外的时间上下文来显著改善当前分数的CBCT图像的分割精度。我们介绍LSTM-UNet,一种创新的体系结构,将长短期内存(LSTM)单元集成到传统U-Net框架的跳过连接中,以保留以前分数的信息。这些模型用模拟数据进行初始预训练,然后对临床数据集进行微调。
    我们提出的模型的分割预测从8个头颈部器官和目标中得出平均Dice相似系数为79%,与没有先验知识的基线模型的52%和具有先验知识但没有记忆的基线模型的78%相比。
    我们提出的模型通过有效利用先验分数的信息,超越了基线分割框架,从而减少了临床医生修改自动分割结果的努力。此外,它与基于注册的方法一起工作,提供更好的先验知识。我们的模型有望集成到在线ART工作流程中,在合成CT图像上提供精确的分割功能。
    UNASSIGNED: Accurate and automated segmentation of targets and organs-at-risk (OARs) is crucial for the successful clinical application of online adaptive radiotherapy (ART). Current methods for cone-beam computed tomography (CBCT) auto-segmentation face challenges, resulting in segmentations often failing to reach clinical acceptability. Current approaches for CBCT auto-segmentation overlook the wealth of information available from initial planning and prior adaptive fractions that could enhance segmentation precision.
    UNASSIGNED: We introduce a novel framework that incorporates data from a patient\'s initial plan and previous adaptive fractions, harnessing this additional temporal context to significantly refine the segmentation accuracy for the current fraction\'s CBCT images. We present LSTM-UNet, an innovative architecture that integrates Long Short-Term Memory (LSTM) units into the skip connections of the traditional U-Net framework to retain information from previous fractions. The models underwent initial pre-training with simulated data followed by fine-tuning on a clinical dataset.
    UNASSIGNED: Our proposed model\'s segmentation predictions yield an average Dice similarity coefficient of 79% from 8 Head & Neck organs and targets, compared to 52% from a baseline model without prior knowledge and 78% from a baseline model with prior knowledge but no memory.
    UNASSIGNED: Our proposed model excels beyond baseline segmentation frameworks by effectively utilizing information from prior fractions, thus reducing the effort of clinicians to revise the auto-segmentation results. Moreover, it works together with registration-based methods that offer better prior knowledge. Our model holds promise for integration into the online ART workflow, offering precise segmentation capabilities on synthetic CT images.
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  • 文章类型: Journal Article
    负义RNA病毒(NSV)包括一些最有害的人类病原体,包括流感,埃博拉病毒,和麻疹病毒。NSV基因组由一个或多个单链RNA分子组成,这些分子被包装成一个或多个核糖核蛋白(RNP)复合物。这些RNP由病毒RNA组成,病毒RNA聚合酶,和病毒核蛋白(NP)的许多拷贝。NSV门内的当前进化关系基于保守的RNA依赖性RNA聚合酶(RdRp)结构域氨基酸序列的比对。然而,基于RdRp域的系统发育没有解决NP,NSV基因组中的另一个核心蛋白,沿着相同的轨迹进化,或者几个RdRp-NP对是否通过分段和非分段NSV基因组架构中的趋同进化而进化。解决NP和RdRp域如何进化可能有助于我们更好地理解NSV多样性。由于NP序列太短,无法推断稳健的系统发育关系,我们在这里使用实验获得的和AlphaFold2.0预测的NP结构来探测是否可以使用NSVNP序列估计进化关系。根据建模结构的灵活结构对齐,我们发现NSVNP的结构同源性揭示了与基于RdRp的聚类一致的系统发育聚类。此外,我们能够根据现有的NP序列将目前缺少RdRp序列的病毒分配到系统发育簇.我们基于RdRp和基于NP的关系都偏离了当前NSV分类的分段Naedrevirales,在我们的分析中与其他分段的NSV聚类。总的来说,我们的结果表明,NSVRdRp和NP基因在很大程度上沿着相似的轨迹进化,甚至是短暂的遗传片段,蛋白质编码信息可以用来推断进化关系,可能使宏基因组分析更有价值。
    Negative sense RNA viruses (NSV) include some of the most detrimental human pathogens, including the influenza, Ebola, and measles viruses. NSV genomes consist of one or multiple single-stranded RNA molecules that are encapsidated into one or more ribonucleoprotein (RNP) complexes. These RNPs consist of viral RNA, a viral RNA polymerase, and many copies of the viral nucleoprotein (NP). Current evolutionary relationships within the NSV phylum are based on the alignment of conserved RNA-dependent RNA polymerase (RdRp) domain amino acid sequences. However, the RdRp domain-based phylogeny does not address whether NP, the other core protein in the NSV genome, evolved along the same trajectory or whether several RdRp-NP pairs evolved through convergent evolution in the segmented and non-segmented NSV genome architectures. Addressing how NP and the RdRp domain evolved may help us better understand NSV diversity. Since NP sequences are too short to infer robust phylogenetic relationships, we here used experimentally obtained and AlphaFold 2.0-predicted NP structures to probe whether evolutionary relationships can be estimated using NSV NP sequences. Following flexible structure alignments of modeled structures, we find that the structural homology of the NSV NPs reveals phylogenetic clusters that are consistent with RdRp-based clustering. In addition, we were able to assign viruses for which RdRp sequences are currently missing to phylogenetic clusters based on the available NP sequence. Both our RdRp-based and NP-based relationships deviate from the current NSV classification of the segmented Naedrevirales, which cluster with the other segmented NSVs in our analysis. Overall, our results suggest that the NSV RdRp and NP genes largely evolved along similar trajectories and even short pieces of genetic, protein-coding information can be used to infer evolutionary relationships, potentially making metagenomic analyses more valuable.
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  • 文章类型: Journal Article
    在超声图像上从周围组织分割卵巢/附件肿块是一项具有挑战性的任务。将质量分离成不同的分量对于放射学特征提取也是重要的。我们的研究旨在开发一种基于人工智能的经阴道超声图像自动分割方法,该方法(1)勾勒出附件肿块的外部边界,(2)分离内部成分。
    对附件肿块的回顾性超声成像数据库进行了审查,以确定患者的排除标准,质量,和图像级别,每个质量一个图像。将53例患者的54个附件肿块(36个良性/18个恶性)按患者分为训练组(26个良性/12个恶性)和独立测试组(10个良性/6个恶性)。使用Dice相似性系数(DSC)和Hausdorff距离与每个质量的轮廓的有效直径(RHD-D)之比,测量了与专家详细轮廓相比的测试图像上的U网分割性能。随后,在发现模式下,使用两级模糊c均值(FCM)无监督聚类方法来分离属于低回声或高回声成分的质量内的像素。
    DSC(中位数[95%置信区间])为0.91[0.78,0.96],RHD-D为0.04[0.01,0.12],表明与专家大纲有很强的一致性。对团块内部分离为回声成分的临床回顾表明,与团块特征密切相关。
    一种用于自动分割附件肿块及其内部组件的U-net和FCM组合算法,与专家概述和审查相比,取得了出色的效果,支持未来基于放射学特征的质量分类。
    UNASSIGNED: Segmentation of ovarian/adnexal masses from surrounding tissue on ultrasound images is a challenging task. The separation of masses into different components may also be important for radiomic feature extraction. Our study aimed to develop an artificial intelligence-based automatic segmentation method for transvaginal ultrasound images that (1) outlines the exterior boundary of adnexal masses and (2) separates internal components.
    UNASSIGNED: A retrospective ultrasound imaging database of adnexal masses was reviewed for exclusion criteria at the patient, mass, and image levels, with one image per mass. The resulting 54 adnexal masses (36 benign/18 malignant) from 53 patients were separated by patient into training (26 benign/12 malignant) and independent test (10 benign/6 malignant) sets. U-net segmentation performance on test images compared to expert detailed outlines was measured using the Dice similarity coefficient (DSC) and the ratio of the Hausdorff distance to the effective diameter of the outline ( R HD - D ) for each mass. Subsequently, in discovery mode, a two-level fuzzy c-means (FCM) unsupervised clustering approach was used to separate the pixels within masses belonging to hypoechoic or hyperechoic components.
    UNASSIGNED: The DSC (median [95% confidence interval]) was 0.91 [0.78, 0.96], and R HD - D was 0.04 [0.01, 0.12], indicating strong agreement with expert outlines. Clinical review of the internal separation of masses into echogenic components demonstrated a strong association with mass characteristics.
    UNASSIGNED: A combined U-net and FCM algorithm for automatic segmentation of adnexal masses and their internal components achieved excellent results compared with expert outlines and review, supporting future radiomic feature-based classification of the masses by components.
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  • 文章类型: Journal Article
    奶牛疾病是人们关注的主要来源。在早期发现的动物中的一些疾病可以在仍然可以治疗的同时进行治疗。如果肿块性皮肤病(LSD)没有得到适当治疗,这可能会给农场畜牧业带来巨大的经济损失。像牛这样的动物会严重影响这种疾病。牛奶产量的减少,生育率降低,生长迟缓,流产,偶尔死亡都是这种疾病对奶牛的有害影响。在过去的三个月里,LSD已经影响了孟加拉国近50个地区的数千头牛,导致养牛农民担心他们的生计。尽管这种病毒具有很强的传染性,在接受了几个月的适当护理后,受影响的牛可以治愈。这项研究的目的是使用各种深度学习和机器学习模型来确定奶牛是否患有块状疾病。为了完成这项工作,提出了一种基于卷积神经网络(CNN)的新型结构来检测疾病。已使用图像预处理和分割技术确定了块状疾病影响区域。在提取了众多特征之后,我们提出的模型已经过评估,可以对LSD进行分类。四个CNN模型,DenseNet,MobileNetV2,Xception,和InceptionResNetV2用于对框架进行分类,并计算评估指标以确定分类器的工作情况。MobileNetV2通过将结果与最近发表的相关作品进行比较,能够实现96%的分类准确率和98%的AUC评分,这看起来既好又有希望。
    Cow diseases are a major source of concern for people. Some diseases in animals that are discovered in their early stages can be treated while they are still treatable. If lumpy skin disease (LSD) is not properly treated, it can result in significant financial losses for the farm animal industry. Animals like cows that sign this disease have their skin seriously affected. A reduction in milk production, reduced fertility, growth retardation, miscarriage, and occasionally death are all detrimental effects of this disease in cows. Over the past three months, LSD has affected thousands of cattle in nearly fifty districts across Bangladesh, causing cattle farmers to worry about their livelihood. Although the virus is very contagious, after receiving the right care for a few months, the affected cattle can be cured. The goal of this study was to use various deep learning and machine learning models to determine whether or not cows had lumpy disease. To accomplish this work, a Convolution neural network (CNN) based novel architecture is proposed for detecting the illness. The lumpy disease-affected area has been identified using image preprocessing and segmentation techniques. After the extraction of numerous features, our proposed model has been evaluated to classify LSD. Four CNN models, DenseNet, MobileNetV2, Xception, and InceptionResNetV2 were used to classify the framework, and evaluation metrics were computed to determine how well the classifiers worked. MobileNetV2 has been able to achieve 96% classification accuracy and an AUC score of 98% by comparing results with recently published relevant works, which seems both good and promising.
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  • 文章类型: Journal Article
    从心电图(ECG)中提取逐次搏动信息对于依赖于基于ECG的测量的各种下游诊断任务至关重要。然而,这些测量可能是昂贵且耗时的,尤其是长期录音。传统的心电检测和勾画方法,依靠经典的信号处理算法,例如基于小波变换的算法,产生高质量的轮廓,但难以推广到不同的心电图模式。基于深度学习算法的机器学习(ML)技术已经成为有希望的替代方案,能够在没有手工制作的功能或阈值的情况下实现类似的性能。然而,有监督的机器学习技术需要大量带注释的数据集进行训练,和用于ECG检测/描绘的现有数据集的大小和它们所代表的病理状况的范围是有限的。
    本文通过介绍两个关键创新来解决这一挑战。首先,我们开发了一种合成数据生成方案,该方案从现有数据库中提取的基本片段的\"池\"中概率地构建看不见的ECG迹线。一组规则将这些片段的排列引导成连贯的合成痕迹,而专家领域知识确保生成的痕迹的真实性,增加训练模型的输入变异性。第二,我们提出了两个新颖的基于分割的损失函数,它们鼓励准确预测独立ECG结构的数量,并通过关注减少的样本数来促进更紧密的分割边界.
    所提出的方法实现了卓越的性能,F1分数为99.38%,心电图节段的起始和偏移在P上的描绘误差为2.19±17.73ms和4.45±18.32ms,QRS,T波。这些结果,从三个不同的免费数据库(QT,LU,和浙江),超越了当前最先进的检测和描绘方法。
    值得注意的是,该模型表现出卓越的性能,尽管在引线配置的变化,采样频率,并代表病理生理机制,强调其强大的泛化能力。现实世界的例子,具有各种病理的临床数据,说明了我们在不同医疗环境中简化ECG分析的方法的潜力,通过释放代码作为开源来促进。
    UNASSIGNED: Extracting beat-by-beat information from electrocardiograms (ECGs) is crucial for various downstream diagnostic tasks that rely on ECG-based measurements. However, these measurements can be expensive and time-consuming to produce, especially for long-term recordings. Traditional ECG detection and delineation methods, relying on classical signal processing algorithms such as those based on wavelet transforms, produce high-quality delineations but struggle to generalise to diverse ECG patterns. Machine learning (ML) techniques based on deep learning algorithms have emerged as promising alternatives, capable of achieving similar performance without handcrafted features or thresholds. However, supervised ML techniques require large annotated datasets for training, and existing datasets for ECG detection/delineation are limited in size and the range of pathological conditions they represent.
    UNASSIGNED: This article addresses this challenge by introducing two key innovations. First, we develop a synthetic data generation scheme that probabilistically constructs unseen ECG traces from \"pools\" of fundamental segments extracted from existing databases. A set of rules guides the arrangement of these segments into coherent synthetic traces, while expert domain knowledge ensures the realism of the generated traces, increasing the input variability for training the model. Second, we propose two novel segmentation-based loss functions that encourage the accurate prediction of the number of independent ECG structures and promote tighter segmentation boundaries by focusing on a reduced number of samples.
    UNASSIGNED: The proposed approach achieves remarkable performance, with a F 1 -score of 99.38% and delineation errors of 2.19 ± 17.73  ms and 4.45 ± 18.32  ms for ECG segment onsets and offsets across the P, QRS, and T waves. These results, aggregated from three diverse freely available databases (QT, LU, and Zhejiang), surpass current state-of-the-art detection and delineation approaches.
    UNASSIGNED: Notably, the model demonstrated exceptional performance despite variations in lead configurations, sampling frequencies, and represented pathophysiology mechanisms, underscoring its robust generalisation capabilities. Real-world examples, featuring clinical data with various pathologies, illustrate the potential of our approach to streamline ECG analysis across different medical settings, fostered by releasing the codes as open source.
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  • 文章类型: Journal Article
    在反射共聚焦显微镜(RCM)图像上准确识别表皮细胞对于研究健康和患病皮肤的表皮结构和拓扑结构非常重要。然而,这些图像的分析目前手动完成,因此耗时,并受到人为错误和专家之间的解释。由于噪声和异质性,它还受到低图像质量的阻碍。
    我们旨在设计一种自动化管道,用于从RCM图像分析表皮结构。
    已经进行了两种自动定位表皮细胞的尝试,称为角质形成细胞,在RCM图像上:第一个是基于旋转对称误差函数掩码,第二个是细胞形态特征。这里,我们提出了一个双任务网络来自动识别RCM图像上的角质形成细胞。每个任务由一个循环生成对抗网络组成。第一项任务旨在将真实的RCM图像转换为二进制图像,从而学习RCM图像的噪声和纹理模型,而第二个任务将Gabor过滤的RCM图像映射为二进制图像,学习RCM图像上可见的表皮结构。两个任务的组合允许一个任务限制另一个任务的解空间,从而提高整体效果。我们通过应用预先训练的StarDist算法来检测星凸形状来完善我们的细胞识别,从而关闭任何不完整的膜并分离相邻的细胞。
    在模拟数据和手动注释的真实RCM数据上评估结果。准确性是使用召回率和精确度指标来衡量的,总结为F1分数。
    我们证明了所提出的完全无监督的方法成功地识别了表皮RCM图像上的角质形成细胞,准确性与专家的细胞识别相当,不受有限的可用注释数据的约束,并且可以扩展到使用各种成像技术获取的图像,而无需重新训练。
    UNASSIGNED: Accurate identification of epidermal cells on reflectance confocal microscopy (RCM) images is important in the study of epidermal architecture and topology of both healthy and diseased skin. However, analysis of these images is currently done manually and therefore time-consuming and subject to human error and inter-expert interpretation. It is also hindered by low image quality due to noise and heterogeneity.
    UNASSIGNED: We aimed to design an automated pipeline for the analysis of the epidermal structure from RCM images.
    UNASSIGNED: Two attempts have been made at automatically localizing epidermal cells, called keratinocytes, on RCM images: the first is based on a rotationally symmetric error function mask, and the second on cell morphological features. Here, we propose a dual-task network to automatically identify keratinocytes on RCM images. Each task consists of a cycle generative adversarial network. The first task aims to translate real RCM images into binary images, thus learning the noise and texture model of RCM images, whereas the second task maps Gabor-filtered RCM images into binary images, learning the epidermal structure visible on RCM images. The combination of the two tasks allows one task to constrict the solution space of the other, thus improving overall results. We refine our cell identification by applying the pre-trained StarDist algorithm to detect star-convex shapes, thus closing any incomplete membranes and separating neighboring cells.
    UNASSIGNED: The results are evaluated both on simulated data and manually annotated real RCM data. Accuracy is measured using recall and precision metrics, which is summarized as the F 1 -score.
    UNASSIGNED: We demonstrate that the proposed fully unsupervised method successfully identifies keratinocytes on RCM images of the epidermis, with an accuracy on par with experts\' cell identification, is not constrained by limited available annotated data, and can be extended to images acquired using various imaging techniques without retraining.
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  • 文章类型: Journal Article
    纹理分离研究表明,某些类型的纹理由基于边缘的机制处理,而其他类型的纹理由基于区域的机制处理。然而,采用名义上基于边缘的纹理的研究已经找到了基于区域的处理机制的证据,当任务是检测而不是分离纹理。在这里,我们直接调查任务的性质是否决定了纹理感知中是否涉及基于区域或基于边缘的机制。刺激由随机定位的Gabor微图案纹理阵列组成,具有五种调制类型:方向调制,方向方差调制,亮度调制,对比度调制和对比度方差调制(CVM)。有四个调制频率:0.1,0.2,0.4和0.8cpd。每种调制类型由三种类型的波形定义:正弦波(SN)及其平滑变化,方波(SQ)和尖波(CS)的锐利的纹理边缘。通过从等振幅方波中去除正弦波来构造CS波形。参与者执行了两项任务:检测参与者选择两种刺激中的哪一种包含调制和辨别,参与者指出两种纹理中的哪一种具有不同的调制方向。我们的结果表明,检测任务中的阈值幅度在所有空间频率上都遵循SQ Texture segregation studies indicate that some types of textures are processed by edge-based and others by region-based mechanisms. However, studies employing nominally edge-based textures have found evidence for region-based processing mechanisms when the task was to detect rather than segregate the textures. Here we investigate directly whether the nature of the task determines if region-based or edge-based mechanisms are involved in texture perception. Stimuli consisted of randomly positioned Gabor micropattern texture arrays with five types of modulation: orientation modulation, orientation variance modulation, luminance modulation, contrast modulation and contrast variance modulation (CVM). There were four modulation frequencies: 0.1, 0.2, 0.4 and 0.8 cpd. Each modulation type was defined by three types of waveforms: sinewave (SN) with its smooth variations, square-wave (SQ) and cusp-wave (CS) with its sharp texture edges. The CS waveform was constructed by removing a sinewave from an equal amplitude square-wave. Participants performed two tasks: detection in which participants selected which of two stimuli contained the modulation and discrimination in which participants indicated which of two textures had a different modulation orientation. Our results indicate that threshold amplitudes in the detection task followed the ordering SQ < SN < CS across all spatial frequencies, consistent with detection being mediated by the overall energy in the stimulus and hence region based. With the discrimination task at low texture spatial frequencies and with CVM textures at all spatial frequencies the order was CS ≤ SQ with both < SN, consistent with being edge-based. We modeled the data by estimating the spatial frequency of a Difference of Gaussian filter that gave the largest peak amplitude response to the data. We found that the peak amplitude was lower for detection than discrimination across all texture types except for the CVM texture. We conclude that task requirements are critical to whether edges or regions underpin texture processing.
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