Real-time COVID-19 detection over chest x-ray images in edge computing

Severe Coronavirus Disease 2019 (COVID-19) has been a global pandemic which provokes massive devastation to the society, economy, and culture since January 2020. The pandemic demonstrates the inefficiency of superannuated manual detection approaches and inspires novel approaches that detect COVID-19 by classifying chest x-ray (CXR) images with deep learning technology. Although a wide range of researches about bran-new COVID-19 detection methods that classify CXR images with centralized convolutional neural network (CNN) models have been proposed, the latency, privacy, and cost of information transmission between the data resources and the centralized data center will make the detection inefficient. Hence, in this article, a COVID-19 detection scheme via CXR images classification with a lightweight CNN model called MobileNet in edge computing is proposed to alleviate the computing pressure of centralized data center and ameliorate detection efficiency. Specifically, the general framework is introduced first to manifest the overall arrangement of the computing and information services ecosystem. Then, an unsupervised model DCGAN is employed to make up for the small scale of data set. Moreover, the implementation of the MobileNet for CXR images classification is presented at great length. The specific distribution strategy of MobileNet models is followed. The extensive evaluations of the experiments demonstrate the efficiency and accuracy of the proposed scheme for detecting COVID-19 over CXR images in edge computing.     

CT图像肺及肺病变区域分割方法综述

计算机断层扫描(computed tomography, CT)技术能为新冠肺炎(corona virus disease 2019,COVID-19)和肺癌等肺部疾病的诊断与治疗提供更全面的信息,但是由于肺部疾病的类型多样且复杂,使得对肺CT图像进行高质量的肺病变区域分割成为计算机辅助诊断的重难点问题。为了对肺CT图像的肺及肺病变区域分割方法的现状进行全面研究,本文综述了近年国内外发表的相关文献：对基于区域和活动轮廓的肺CT图像传统分割方法的优缺点进行比较与总结,传统的肺CT图像分割方法因其实现原理简单且分割速度快等优点,早期使用较多,但其存在分割精度不高的缺点,目前仍有不少基于传统方法的改进策略;重点分析了基于卷积神经网络(convolutional neural network, CNN)、全卷积网络(fully convolutional network, FCN)、U-Net和生成对抗网络(generative adversarial network, GAN)的肺CT图像分割网络结构改进模型的研究进展,基于深度学习的分割方法具有分割精度高、迁移学习能力强和鲁棒性高等优点,特...     

COVID-19肺部CT图像多尺度编解码分割

目的 新型冠状病毒肺炎(corona virus disease 2019, COVID-19)患者肺部计算机断层扫描(computed tomography, CT)图像具有明显的病变特征,快速而准确地从患者肺部CT图像中分割出病灶部位,对COVID-19患者快速诊断和监护具有重要意义。COVID-19肺炎病灶区域复杂多变,现有方法分割精度不高,且对假阴性的关注不够,导致分割结果往往具有较高的特异度,但灵敏度却很低。方法 本文提出了一个基于深度学习的多尺度编解码网络(MED-Net(multiscale encode decode network)),该网络采用资源利用率高、计算速度快的HarDNet68(harmonic densely connected network)作为主干,它主要由5个harmonic dense block(HDB)组成,首先通过5个空洞空间卷积池化金字塔(atrous spatial pyramid pooling, ASPP)对HarDNet68的第1个卷积层和第1、3、4、5个HDB提取多尺度特征。接着在并行解码器(paralleled parti...     

融合多头注意力机制的新冠肺炎联合诊断与分割

目的 新冠肺炎疫情席卷全球,为快速诊断肺炎患者,确认患者肺部感染区域,大量检测网络相继提出,但现有网络大多只能处理一种任务,即诊断或分割。本文提出了一种融合多头注意力机制的联合诊断与分割网络,能同时完成X线胸片的肺炎诊断分类和新冠感染区分割。方法 整个网络由3部分组成,双路嵌入层通过两种不同的图像嵌入方式分别提取X线胸片的浅层直观特征和深层抽象特征;Transformer模块综合考虑提取到的浅层直观与深层抽象特征;分割解码器扩大特征图以输出分割区域。为响应联合训练,本文使用了一种混合损失函数以动态平衡分类与分割的训练。分类损失定义为分类对比损失与交叉熵损失的和;分割损失是二分类的交叉熵损失。结果 基于6个公开数据集的合并数据实验结果表明,所提网络取得了95.37%的精度、96.28%的召回率、95.95%的F1指标和93.88%的kappa系数,诊断分类性能超过了主流的ResNet50、VGG16(Visual Geometry Group)和Inception＿v3等网络;在新冠病灶分割表现上,相比流行的U-Net及其改进网络,取得最高的精度(95.96%),优异的敏感度(78.89...     

结构图注意力网络的新冠肺炎轻重症诊断

目的 为辅助医生快速分辨新型冠状病毒肺炎(corona virus disease 2019, COVID-19)轻、重症患者,以便对症下药减轻医疗负担,提出一种基于结构图注意力网络的轻重症诊断算法。方法 基于胸部CT图像提取的特定特征以及肺段间的位置关系构建结构图,以肺部内不同肺段为节点,以提取特征为节点属性。采用图神经网络汇聚相邻节点特征,再利用池化层获取分别代表左肺叶和右肺叶特征的图表示。使用结构注意力机制计算左、右肺叶的感染情况对结果诊断的重要性,并依据重要性融合左、右肺叶图表示以得到最终图表示,最后执行分类任务。由于数据中存在明显的类别不平衡现象,采用Focal-Loss损失函数优化模型以减轻对分类结果的影响。结果 实验将所提算法分别与传统机器学习方法和流行的图神经网络算法做性能对比。在重症诊断的准确率上,本文算法相较于传统机器学习方法和图神经网络算法分别取得14.2%～42.0%和3.6%～4.8%的提升。在AUC(area under curve)指标上,本文算法相较于上述两种算法分别取得8.9%～18.7%和3.1%～3.6%的提升。除此之外,通过消融实验发现具有结构注...     

An Optimized CNN Model Architecture for Detecting Coronavirus (COVID-19) with X-Ray Images

This paper demonstrates empirical research on using convolutional neural networks (CNN) of deep learning techniques to classify X-rays of COVID-19 patients versus normal patients by feature extraction. Feature extraction is one of the most significant phases for classifying medical X-rays radiography that requires inclusive domain knowledge. In this study, CNN architectures such as VGG-16, VGG-19, RestNet50, RestNet18 are compared, and an optimized model for feature extraction in X-ray images from various domains involving several classes is proposed. An X-ray radiography classifier with TensorFlow GPU is created executing CNN architectures and our proposed optimized model for classifying COVID-19 (Negative or Positive). Then, 2,134 X-rays of normal patients and COVID-19 patients generated by an existing open-source online dataset were labeled to train the optimized models. Among those, the optimized model architecture classifier technique achieves higher accuracy (0.97) than four other models, specifically VGG-16, VGG-19, RestNet18, and RestNet50 (0.96, 0.72, 0.91, and 0.93, respectively). Therefore, this study will enable radiologists to more efficiently and effectively classify a patient’s coronavirus disease.     

新型冠状病毒肺炎(COVID-19)医学影像AI诊断研究进展

2020年3月,世界卫生组织（World Health Organization,WHO）宣布新型冠状病毒肺炎（corona virus disease 2019,COVID-19）为世界大流行病,疫情的爆发给世界各地医疗系统带来巨大压力。现有的COVID-19诊断标准是核酸检测阳性,然而核酸检测假阴性率高达17%~25.5%,为避免漏诊,需要采用基于影像学的AI诊断方法筛查大量疑似病例,扼制疾病传播。本综述将回顾疫情爆发数月以来,基于医学影像的新冠肺炎AI辅助诊断的研究成果。首先介绍CT（computed tomography）和X光片的优缺点,以及COVID-19的放射学特征,然后对数据准备、图像分割和分类识别等AI诊断的关键步骤分别进行阐述,最后介绍COVID-19的跟踪和预后（预先对疾病后续发展过程及结果的判断和估计）。本文还整理了部分公开的COVID-19相关数据集,并对数据标注不足的问题提供了弱监督学习和迁移学习等解决方案。实验验证,AI系统诊断COVID-19的敏感性达到97.4%,特异性达到92.2%,优于放射科医生的诊断结果。其中表现尤为突出的是基于语义分割网络检测COVID-19感染区域,由此可以定量分析感染率。AI系统可以辅助医生诊断和治疗COVID-19,提高放射科医生阅读X光片和CT的效率。     

Differentiation of COVID-19 conditions in planar chest radiographs using optimized convolutional neural networks

In this study, an attempt has been made to differentiate Novel Coronavirus-2019 (COVID-19) conditions from healthy subjects in Chest radiographs using a simplified end-to-end Convolutional Neural Network (CNN) model and occlusion sensitivity maps. Early detection and faster automated screening of the COVID-19 patients is essential. For this, the images are considered from publicly available datasets. Significant biomarkers representing critical image features are extracted from CNN by experimentally investigating on cross-validation methods and hyperparameter settings. The performance of the network is evaluated using standard metrics. Perturbation based occlusion sensitivity maps are employed on the features obtained from the classification model to visualise the localization of abnormal areas. Results demonstrate that the simplified CNN model with optimised parameters is able to extract significant features with a sensitivity of 97.35% and F-measure of 96.71% to detect COVID-19 images. The algorithm achieves an Area Under the Curve-Receiver Operating Characteristic score of 99.4% with Matthews correlation coefficient of 0.93. High value of Diagnostic odds ratio is also obtained. Occlusion sensitivity maps provide precise localization of abnormal regions by identifying COVID-19 conditions. As early detection through chest radiographic images are useful for automated screening of the disease, this method appears to be clinically relevant in providing a visual diagnostic solution using a simplified and efficient model.

     

SELDNet: Sequenced encoder and lightweight decoder network for COVID-19 infection region segmentation

Segmenting regions of lung infection from computed tomography (CT) images shows excellent potential for rapid and accurate quantifying of Coronavirus disease 2019 (COVID-19) infection and determining disease development and treatment approaches. However, a number of challenges remain, including the complexity of imaging features and their variability with disease progression, as well as the high similarity to other lung diseases, which makes feature extraction difficult. To answer the above challenges, we propose a new sequence encoder and lightweight decoder network for medical image segmentation model (SELDNet). (i) Construct sequence encoders and lightweight decoders based on Transformer and deep separable convolution, respectively, to achieve different fine-grained feature extraction. (ii) Design a semantic association module based on cross-attention mechanism between encoder and decoder to enhance the fusion of different levels of semantics. The experimental results showed that the network can effectively achieve segmentation of COVID-19 infected regions. The dice of the segmentation result was 79.1%, the sensitivity was 76.3%, and the specificity was 96.7%. Compared with several state-of-the-art image segmentation models, our proposed SELDNet model achieves better results in the segmentation task of COVID-19 infected regions.     

Automatic Detection of COVID-19 Infection Using Chest X-Ray Images Through Transfer Learning

The new coronavirus(COVID-19),declared by the World Health Organization as a pandemic,has infected more than 1 million people and killed more than 50 thousand.An infection caused by COVID-19 can develop into pneumonia,which can be detected by a chest X-ray exam and should be treated appropriately.In this work,we propose an automatic detection method for COVID-19 infection based on chest X-ray images.The datasets constructed for this study are composed of194 X-ray images of patients diagnosed with coronavirus and 194 X-ray images of healthy patients.Since few images of patients with COVID-19 are publicly available,we apply the concept of transfer learning for this task.We use different architectures of convolutional neural networks(CNNs)trained on Image Net,and adapt them to behave as feature extractors for the X-ray images.Then,the CNNs are combined with consolidated machine learning methods,such as k-Nearest Neighbor,Bayes,Random Forest,multilayer perceptron(MLP),and support vector machine(SVM).The results show that,for one of the datasets,the extractor-classifier pair with the best performance is the Mobile Net architecture with the SVM classifier using a linear kernel,which achieves an accuracy and an F1-score of 98.5%.For the other dataset,the best pair is Dense Net201 with MLP,achieving an accuracy and an F1-score of 95.6%.Thus,the proposed approach demonstrates efficiency in detecting COVID-19 in X-ray images.     

COVID-19 chest X-ray image classification in the presence of noisy labels

The Corona Virus Disease 2019 (COVID-19) has been declared a worldwide pandemic, and a key method for diagnosing COVID-19 is chest X-ray imaging. The application of convolutional neural network with medical imaging helps to diagnose the disease accurately, where the label quality plays an important role in the classification problem of COVID-19 chest X-rays. However, most of the existing classification methods ignore the problem that the labels are hardly completely true and effective, and noisy labels lead to a significant degradation in the performance of image classification frameworks. In addition, due to the wide distribution of lesions and the large number of local features of COVID-19 chest X-ray images, existing label recovery algorithms have to face the bottleneck problem of the difficult reuse of noisy samples. Therefore, this paper introduces a general classification framework for COVID-19 chest X-ray images with noisy labels and proposes a noisy label recovery algorithm based on subset label iterative propagation and replacement (SLIPR). Specifically, the proposed algorithm first obtains random subsets of the samples multiple times. Then, it integrates several techniques such as principal component analysis, low-rank representation, neighborhood graph regularization, and k-nearest neighbor for feature extraction and image classification. Finally, multi-level weight distribution and replacement are performed on the labels to cleanse the noise. In addition, for the label-recovered dataset, high confidence samples are further selected as the training set to improve the stability and accuracy of the classification framework without affecting its inherent performance. In this paper, three typical datasets are chosen to conduct extensive experiments and comparisons of existing algorithms under different metrics. Experimental results on three publicly available COVID-19 chest X-ray image datasets show that the proposed algorithm can effectively recover noisy labels and improve the accuracy of the image classification framework by 18.9% on the Tawsifur dataset, 19.92% on the Skytells dataset, and 16.72% on the CXRs dataset. Compared to the state-of-the-art algorithms, the gain of classification accuracy of SLIPR on the three datasets can reach 8.67%-19.38%, and the proposed algorithm also has certain scalability while ensuring data integrity.     

Stacked-autoencoder-based model for COVID-19 diagnosis on CT images

With the outbreak of COVID-19, medical imaging such as computed tomography (CT) based diagnosis is proved to be an effective way to fight against the rapid spread of the virus. Therefore, it is important to study computerized models for infectious detection based on CT imaging. New deep learning-based approaches are developed for CT assisted diagnosis of COVID-19. However, most of the current studies are based on a small size dataset of COVID-19 CT images as there are less publicly available datasets for patient privacy reasons. As a result, the performance of deep learning-based detection models needs to be improved based on a small size dataset. In this paper, a stacked autoencoder detector model is proposed to greatly improve the performance of the detection models such as precision rate and recall rate. Firstly, four autoencoders are constructed as the first four layers of the whole stacked autoencoder detector model being developed to extract better features of CT images. Secondly, the four autoencoders are cascaded together and connected to the dense layer and the softmax classifier to constitute the model. Finally, a new classification loss function is constructed by superimposing reconstruction loss to enhance the detection accuracy of the model. The experiment results show that our model is performed well on a small size COVID-2019 CT image dataset. Our model achieves the average accuracy, precision, recall, and F1-score rate of 94.7%, 96.54%, 94.1%, and 94.8%, respectively. The results reflect the ability of our model in discriminating COVID-19 images which might help radiologists in the diagnosis of suspected COVID-19 patients.

     

Learning Patterns from COVID-19 Instances

Coronavirus disease, which resulted from the SARS-CoV-2 virus, has spread worldwide since early 2020 and has been declared a pandemic by the World Health Organization (WHO). Coronavirus disease is also termed COVID-19. It affects the human respiratory system and thus can be traced and tracked from the Chest X-Ray images. Therefore, Chest X-Ray alone may play a vital role in identifying COVID-19 cases. In this paper, we propose a Machine Learning (ML) approach that utilizes the X-Ray images to classify the healthy and affected patients based on the patterns found in these images. The article also explores traditional, and Deep Learning (DL) approaches for COVID-19 patterns from Chest X-Ray images to predict, analyze, and further understand this virus. The experimental evaluation of the proposed approach achieves 97.5% detection performance using the DL model for COVID-19 versus normal cases. In contrast, for COVID-19 versus Pneumonia Virus scenario, we achieve 94.5% accurate detections. Our extensive evaluation in the experimental section guides and helps in the selection of an appropriate model for similar tasks. Thus, the approach can be used for medical usages and is particularly pertinent in detecting COVID-19 positive patients using X-Ray images alone.     

一种辅助新型冠状病毒肺炎检测的肺实质分割算法

新型冠状病毒肺炎给人类健康及社会经济造成了巨大的负面影响,而X光胸片中的肺实质提取成为新型冠状病毒肺炎诊断过程中的关键环节。在U-Net的基础上,提出一种结合编解码模式的肺实质分割算法。应用特征融合思想,构建A形特征融合模块,充分学习深层特征的语义信息。引入注意力机制,在深层卷积神经网络中加入密集空洞卷积模块和残差多核池化模块,扩大卷积感受野并提取上下文特征信息。通过改进可变形卷积和分割损失函数,提升网络模型的泛化能力和鲁棒性。实验结果表明,该算法的分割准确度、Dice系数、敏感度、Jaccard指数分别为98.16%、98.32%、98.13%、98.54%,能够实现X光胸片中肺实质部位的有效分割。     

COVID-19医学影像数据集及研究进展

由于影像学技术在新型冠状病毒肺炎（COVID-19）的诊断和评估中发挥了重要作用,COVID-19相关数据集陆续被公布,但目前针对相关文献中数据集以及研究进展的整理相对较少。为此,通过COVID-19相关的期刊论文、报告和相关开源数据集网站,对涉及到的新冠肺炎数据集及深度学习模型进行整理和分析,包括计算机断层扫描（CT）图像数据集和X射线（CXR）图像数据集。对这些数据集呈现的医学影像的特征进行分析;重点论述开源数据集,以及在相关数据集上表现较好的分类和分割模型。最后讨论了肺部影像学技术未来的发展趋势。     

Prediction of Covid-19 Based on Chest X-Ray Images Using Deep Learning with CNN

The COVID-19 pandemic has caused trouble in people’s daily lives and ruined several economies around the world, killing millions of people thus far. It is essential to screen the affected patients in a timely and cost-effective manner in order to fight this disease. This paper presents the prediction of COVID-19 with Chest X-Ray images, and the implementation of an image processing system operated using deep learning and neural networks. In this paper, a Deep Learning, Machine Learning, and Convolutional Neural Network-based approach for predicting Covid-19 positive and normal patients using Chest X-Ray pictures is proposed. In this study, machine learning tools such as TensorFlow were used for building and training neural nets. Scikit-learn was used for machine learning from end to end. Various deep learning features are used, such as Conv2D, Dense Net, Dropout, Maxpooling2D for creating the model. The proposed approach had a classification accuracy of 96.43 percent and a validation accuracy of 98.33 percent after training and testing the X-Ray pictures. Finally, a web application has been developed for general users, which will detect chest x-ray images either as covid or normal. A GUI application for the Covid prediction framework was run. A chest X-ray image can be browsed and fed into the program by medical personnel or the general public.     

Deep-CoV: An integrated deep learning model to detect COVID-19 using chest X-ray and CT images

The COVID-19 virus has fatal effect on lung function and due to its rapidity the early detection is necessary at the moment. The radiographic images have already been used by the researchers for the early diagnosis of COVID-19. Though several existing research exhibited very good performance with either x-ray or computer tomography (CT) images, to the best of our knowledge no such work has reported the assembled performance of both x-ray and CT images. Thus increase in accuracy with higher scalability is the main concern of the recent research. In this article, an integrated deep learning model has been developed for detection of COVID-19 at an early stage using both chest x-ray and CT images. The lack of publicly available data about COVID-19 disease motivates the authors to combine three benchmark datasets into a single dataset of large size. The proposed model has applied various transfer learning techniques for feature extraction and to find out the best suite. Finally the capsule network is used to categorize the sub-dataset into COVID positive and normal patients. The experimental results show that, the best performance exhibits by the ResNet50 with capsule network as an extractor-classifier pair with the combined dataset, which is composed of 575 numbers of x-ray images and 930 numbers of CT images. The proposed model achieves accuracy of 98.2% and 97.8% with x-ray and CT images, respectively, and an average of 98%.     

Leveraging Multimodal Ensemble Fusion-Based Deep Learning for COVID-19 on Chest Radiographs

Recently, COVID-19 has posed a challenging threat to researchers, scientists, healthcare professionals, and administrations over the globe, from its diagnosis to its treatment. The researchers are making persistent efforts to derive probable solutions for managing the pandemic in their areas. One of the widespread and effective ways to detect COVID-19 is to utilize radiological images comprising X-rays and computed tomography (CT) scans. At the same time, the recent advances in machine learning (ML) and deep learning (DL) models show promising results in medical imaging. Particularly, the convolutional neural network (CNN) model can be applied to identifying abnormalities on chest radiographs. While the epidemic of COVID-19, much research is led on processing the data compared with DL techniques, particularly CNN. This study develops an improved fruit fly optimization with a deep learning-enabled fusion (IFFO-DLEF) model for COVID-19 detection and classification. The major intention of the IFFO-DLEF model is to investigate the presence or absence of COVID-19. To do so, the presented IFFO-DLEF model applies image pre-processing at the initial stage. In addition, the ensemble of three DL models such as DenseNet169, EfficientNet, and ResNet50, are used for feature extraction. Moreover, the IFFO algorithm with a multilayer perceptron (MLP) classification model is utilized to identify and classify COVID-19. The parameter optimization of the MLP approach utilizing the IFFO technique helps in accomplishing enhanced classification performance. The experimental result analysis of the IFFO-DLEF model carried out on the CXR image database portrayed the better performance of the presented IFFO-DLEF model over recent approaches.     

基于深度学习的COVID-19智能诊断系统

本研究旨在探索运用深度学习的方法辅助医生利用胸部X光片进行COVID-19诊断的可行性和准确性。首先利用公开的COVID-QU-Ex Dataset训练集训练一个UNet分割模型,实现肺部ROI区域的自动分割。其次完成对该公共数据集肺部区域的自动提取预处理。再次利用预处理后的三分类影像数据（新冠肺炎、其它肺炎、正常）采用迁移学习的方式训练了一个分类模型MBCA-COVIDNET,该模型以MobileNetV2作为骨干网络,并在其中加入坐标注意力机制（CA）。最后利用训练好的模型和Hugging Face开源软件搭建了一套方便医生使用的COVID-19智能辅助诊断系统。该模型在COVID-QU-Ex Dataset测试集上取得了高达97.98%的准确率,而该模型的参数量和MACs仅有2.23M和0.33G,易于在硬件设备上进行部署。该智能诊断系统能够很好的辅助医生进行基于胸片的COVID-19诊断,提升诊断的准确率以及诊断效率。     

改进Faster R-CNN模型的CT图磨玻璃密度影目标检测

目的 针对Faster R-CNN （faster region convolutional neural network）模型在肺部计算机断层扫描（computed tomography，CT）图磨玻璃密度影目标检测中小尺寸目标无法有效检测与模型检测速度慢等问题，对Faster R-CNN模型特征提取网络与区域候选网络（region proposal network，RPN）提出了改进方法。方法 使用特征金字塔网络替换Faster R-CNN的特征提取网络，生成特征金字塔；使用基于位置映射的RPN产生锚框，并计算每个锚框的中心到真实物体中心的远近程度（用参数“中心度”表示），对RPN判定为前景的锚框进一步修正位置作为候选区域（region proposal），并将RPN预测的前景/背景分类置信度与中心度结合作为候选区域的排序依据，候选区域经过非极大抑制筛选出感兴趣区域（region of interest，RoI）。将RoI对应的特征区域送入分类回归网络得到检测结果。结果 实验结果表明，在新冠肺炎患者肺部CT图数据集上，本文改进的模型相比于Faster R-CNN模型，召回率（recall）增加了7%，平均精度均值（mean average precision，mAP）增加了3.9%，传输率（frames per second，FPS）由5帧/s提升至9帧/s。特征金字塔网络的引入明显提升了模型的召回率与mAP指标，基于位置映射的RPN显著提升了模型的检测速度。与其他最新改进的目标检测模型相比，本文改进的模型保持了双阶段目标检测模型的高精度，并拉近了与单阶段目标检测模型在检测速度指标上的距离。结论 本文改进的模型能够有效检测到患者肺部CT图的磨玻璃密度影目标区域，对小尺寸目标同样适用，可以快速有效地为医生提供辅助诊断。