Introduction
A current outbreak of pneumonia related to a novel coronavirus, termed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was reported in Wuhan, Hubei province, China in December 2019. The infection spread across other countries round the world (Zhu et al.). On January 30, 2020, the World Health Organization (WHO) stated the outbreak a Public Health Emergency of International Concern (Sohrabi et al., 2020).the symptoms of COVID-19 can be fever, dry cough, fatigue, shortness of breath, myalgia or even no symptoms (Diao et al., 2020, Wan et al., 2020, Shang et al., 2020, Huang et al., 2020, Zarghami et al., 2020).likewise, the studies revealed that older age, male gender, leukocytosis, and Blood laboratory findings, also, comorbidities such as high lactate dehydrogenase level, cardiac injury, hypertension, diabetes mellitus, hypothyroidism, coronary artery disease, smoking and hyperglycemia, were related to weak prognosis in COVID-19 patients (Zhang et al., 2020b, Li et al., 2020, Zarghami et al., 2019).Though, information concerning to clinical features of COVID-19 is still making it difficult for physicians to distinguish the causative agents without related laboratory analysis(Wu and McGoogan, 2020).Furthermore, reverse transcription-polymerase chain reaction (RT-), the gold standard for confirming diagnosis of COVID-19, has some restrictions, such as false negative results and limited sampling method and the rate of high false negative and unavailability of in the early stage of the outbreak restricted fast diagnosis of infection in patients(Fang et al., 2020). The high resolution computed tomography (HRCT) of the chest is progressively recognized as a strong indicator for early diagnosis, and can be the key to the evaluation of COVID-19 suspected patients because the changes in chest imaging sometimes maybe earlier than symptoms (He et al., 2020). HRCT is strongly recommended because it is very sensitive to detecting early disease, assessing the nature and extent of lesions (Yang et al., 2020a). Other investigators examined chest HRCTs in infected patients and found high rates of ground-glass opacities and consolidation, sometimes with a rounded morphology and peripheral lung distribution (Yang et al., 2020b, Pan et al., 2020, Chung et al., 2020).
Chest HRCT can identify the early phase lung infection(Wong et al., 2020, Kanne, 2020) and prompt larger public health surveillance and response systems (Ng et al., 2020). Currently, chest HRCT have been recommended as main evidence for confirmed clinical and laboratory diagnosis. Considering the previous studies, the purpose of the study is to make the early diagnosis, by describing the complete chest HRCT appearances, related laboratory analysis and clinical features of patients with COVID-19, who were hospitalized to the Imam Khomeini Hospital .