SARS-CoV-2 (COVID-19) is a pandemic disease. It is important to reach COVID-19 diagnosis in the emergency departments to make proper care and prevent disease dissemination. COVID-19 diagnosis is based on detection of viral RNA by real time PCR in the oral-nasopharyngeal swabs sample. However, this test requires several hours in laboratories, and has suboptimal sensitivity. RT-PCR assay is the gold standard for diagnosis of COVID-19.  However, (30–50%) of results may be false negative because of sampling position and possible low viral load. Many cases were reported to be RT-PCR negative and CT positive results. Also, Initial CT was found to have (98%) detection rate higher than first RT-PCR (71%). In addition, CT scan does not need significant time (about 5 second) in comparison to time needed for RT-PCR. However, CT has poor specificity, So that, there is an urgent need for another method to be considered as first line approach.