The optimal diagnostic methods for COVID-19.

As the world continues to study and understand coronavirus disease (COVID-19), existing investigations and tests have been used to try and detect the virus to slow viral transmission and its global spread. A 'gold-standard' investigation has not yet been identified for detection and monitoring. Initially, computed tomography (CT) was the mainstay investigation as it shows the disease severity and recovery, and its images change at different stages of the disease. However, CT has been found to have limited sensitivity and negative predictive value in the early stages of the disease, and the value of its use has come under debate due to whether its images change the treatment plan, the risk of radiation, as well as its practicality with infection control. Therefore, there has been a shift to the use of other imaging modalities and tests, such as chest X-rays and ultrasound. Furthermore, the use of nucleic acid-based testing such as reverse-transcriptase polymerase chain reaction (RT-PCR) have proven useful with direct confirmation of COVID-19 infection. In this study, we aim to review and analyse current literature to compare RT-PCR, immunological biomarkers, chest radiographs, ultrasound and chest CT scanning as methods of diagnosing COVID-19.