In December 2019, the novel coronavirus disease 2019 (COVID-19) appeared. Being highly contagious and with no effective treatment available, the only solution was to detect and isolate infected patients to further break the chain of infection. The shortage of test kits and other drawbacks of lab tests motivated researchers to build an automated diagnosis system using chest X-rays and CT scanning. The reviewed works in this study use AI coupled with the radiological image processing of raw chest X-rays and CT images to train various CNN models. They use transfer learning and numerous types of binary and multi-class classifications. The models are trained and validated on several datasets, the attributes of which are also discussed. The obtained results of various algorithms are later compared using performance metrics such as accuracy, F1 score, and AUC. Major challenges faced in this research domain are the limited availability of COVID image data and the high accuracy of the prediction of the severity of patients using deep learning compared to well-known methods of COVID-19 detection such as PCR tests. These automated detection systems using CXR technology are reliable enough to help radiologists in the initial screening and in the immediate diagnosis of infected individuals. They are preferred because of their low cost, availability, and fast results.

The latest threat to global health is the coronavirus disease 2019 (COVID-19) pandemic. To prevent COVID-19, recognizing and isolating the infected patients is an essential step. The primary diagnosis method is Reverse Transcription Polymerase Chain Reaction (RT-PCR) test. However, the sensitivity of this test is not satisfactory to successfully control the COVID-19 outbreak. Although there exist many datasets of chest X-rays (CXR) images, but few COVID-19 CXRs are presently accessible owing to privacy of patients. Thus, many researchers have utilized data augmentation techniques to augment the datasets. But, it may cause over-fitting issues, as the existing data augmentation techniques include small modifications to CXRs. Therefore, in this paper, an efficient deep convolutional generative adversarial network and convolutional neural network (DGCNN) is designed to diagnose COVID-19 suspected subjects. Deep convolutional generative adversarial network (DGAN) consists of two networks trained adversarially such that one generates fake images and the other differentiates between them. Thereafter, convolutional neural network (CNN) is utilized for classification purpose. Extensive experiments are conducted to evaluate the performance of the proposed DGCNN. Performance analysis demonstrates that DGCNN can highly improves the diagnosis performance.