The Role of Chest High Resolution CT and RT-PCR in Diagnosis of Different Stages of Coronavirus (COVID-19) Pneumonia

Purpose: The purpose of this study is to investigate how RT-PCR (real time–polymerase-chain-reaction) and chest High-Resolution Computed Tomography(HRCT) can detect COVID-19 (Coronavirus Disease 2019) disease in the early, progressive and severe stages, as well as patient’s outcome. Method: We perform a prospective study with chest HRCT on 206 patients with positive RT-PCR test. The patients were divided into three groups; earlystage (100 patients), progressive stage (70 patients) and severe stage (36 patients). Results: The early stage involved typical category (COVID-19 Reporting and Data System, CO-RADS 5, 34 cases - 34%), indeterminate category (CORADS3, six cases - 6%), atypical category (CO-RADS 4, ten cases - 10%) and normal chest HRCT imaging (CO-RADS 1, 50 cases - 50%). Theprogressive stage involved a typical category (CO-RADS 5, 70 cases, 100%), The severe stage involved a typical category (CO-RADS 5, 36 cases,100%). Conclusion: RT-PCR is the gold standard and specific tool for confirming COVID-19 infection. Combination of RT-PCR and chest HRCT is used for the earlydiagnosis of COVID-19 pneumonia. Chest HRCT is positive in 50% of patients in the early stage of COVID-19. Chest HRCT is not only detectingpulmonary parenchymal changes but also determining patient’s outcome in the progressive and severe stages of COVID-19 (CO-RADS 5).Patients with progressive stage will not need ventilator and patients with severe stage should receive ventilator.