COVID-19 diagnosis using state-of-the-art CNN architecture features and Bayesian Optimization

• Published in: Computers in biology and medicine Vol. 142; p. 105244
• Main Authors: Aslan, Muhammet Fatih, Sabanci, Kadir, Durdu, Akif, Unlersen, Muhammed Fahri
• Format: Journal Article
• Language: English
• Published: United States Elsevier Ltd 01.03.2022; Elsevier Limited
• Subjects: Accuracy; Algorithms; Artificial intelligence; Artificial neural networks; Bayes Theorem; Bayesian analysis; Bayesian Optimization; Classification; Computed tomography; Convolutional neural networks; Coronaviruses; COVID-19; COVID-19 pandemic; COVID-19 Testing; Decision trees; Deep Learning; Diagnosis; Disease control; Disease transmission; Fatalities; Feature extraction; Humans; Image classification; Image processing; Image segmentation; Infections; Internal Medicine; Learning algorithms; Learning theory; Lungs; Machine learning; Mathematical models; Medical diagnosis; Medical imaging; Methods; Neural networks; Neural Networks, Computer; Optimization; Other; Pneumonia; Polymerase chain reaction; Radiography; SARS-CoV-2; Success; Support vector machines; Tomography; Viral diseases; X ray imagery; Bayesian Optimization; COVID-19 pandemic; Convolutional neural networks; Machine learning
• DOI: 10.1016/j.compbiomed.2022.105244
• ISSN: 0010-4825; 1879-0534

The coronavirus outbreak 2019, called COVID-19, which originated in Wuhan, negatively affected the lives of millions of people and many people died from this infection. To prevent the spread of the disease, which is still in effect, various restriction decisions have been taken all over the world. In addition, the number of COVID-19 tests has been increased to quarantine infected people. However, due to the problems encountered in the supply of RT-PCR tests and the ease of obtaining Computed Tomography and X-ray images, imaging-based methods have become very popular in the diagnosis of COVID-19. Therefore, studies using these images to classify COVID-19 have increased. This paper presents a classification method for computed tomography chest images in the COVID-19 Radiography Database using features extracted by popular Convolutional Neural Networks (CNN) models (AlexNet, ResNet18, ResNet50, Inceptionv3, Densenet201, Inceptionresnetv2, MobileNetv2, GoogleNet). The determination of hyperparameters of Machine Learning (ML) algorithms by Bayesian optimization, and ANN-based image segmentation are the two main contributions in this study. First of all, lung segmentation is performed automatically from the raw image with Artificial Neural Networks (ANNs). To ensure data diversity, data augmentation is applied to the COVID-19 classes, which are fewer than the other two classes. Then these images are applied as input to five different CNN models. The features extracted from each CNN model are given as input to four different ML algorithms, namely Support Vector Machine (SVM), k-Nearest Neighbors (k-NN), Naive Bayes (NB), and Decision Tree (DT) for classification. To achieve the most successful classification accuracy, the hyperparameters of each ML algorithm are determined using Bayesian optimization. With the classification made using these hyperparameters, the highest success is obtained as 96.29% with the DenseNet201 model and SVM algorithm. The Sensitivity, Precision, Specificity, MCC, and F1-Score metric values for this structure are 0.9642, 0.9642, 0.9812, 0.9641 and 0.9453, respectively. These results showed that ML methods with the most optimum hyperparameters can produce successful results. •Selecting lungs from raw image with ANN-based image segmentation.•Extracting features from lung images with pre-trained CNN models.•Determining the best machine learning parameters with Bayesian Optimization.•Covid-19 detection with high accuracy with the proposed method.