4. DISCUSSION
According the findings of the present study, it seems that there is a significant relationship between chest CT scan characteristics and change clinical parameters with outcomes of COVID-19 cases. Based on this results ground Glass Opacity (GGO) and consolidation were the most common chest CT scan findings, which was match to other researches21,22. The most common location of abnormalities was lower zone involvement that observed more than upper zone, which was consistent with findings of other studies 19,23. An investigation carried out on other patients show that CT reports will be more obvious, when revealed longer the onset of symptoms24. In this study radiological patterns have correlation with the stages of the development disease, which was in match to the studies 24,25. The findings of this study indicated ALT, AST, CRP, NEU, LDH, and Urea have very good accuracy in predicting cases with positive RT-PC R for COVID-19, respectively. Also, liver injury is more prevalent in severe cases compared to mild cases of COVID-19. This study was similar to study Chen et al. Another study indicated that 2–11%of patients with COVID-19 had ALT and AST levels during progression of COVID-19 disease 19. In comparison to the normal range, in patients with positive RT-PCR COVID19, the rate of WBC and LYM counts was decreased and NEU counts increase, which is in line with another study 26. The COVID -19 Virus extensive through the respiratory system and infected immune cells and causing changes in number of peripheral white blood cells such as lymphocytes 27. Various studies proposed the substantial decrease in the number of lymphocytes following infection with the coronavirus that influence immune cells and prevent immune action 28. Also, others report show that high neutrophil count and LDH level in COVID-19 patients were autonomous predictors of an adverse clinical outcome 29. The results of laboratory parameters in this study, such as ALT, CRP, AST, LDH, and NEU indicated that there could be used to foretell the presence of COVID-19 disease, while WBC were poor predicted of the disease. This information is match to findings reported by Wang et al.30 and Gao et al. 31. Thus, some laboratory parameters can use to screening cases with positive RT-PCR forCOVID-19. Overall, Clinical course of the COVID-19 disease is unforeseeable, due to the heterogeneity of its manifestations and multi organ failure. At present, there are no prognostic biological markers to identify Covid 19 patients and estimate their associated mortality. It seems that predicting CT scan reports of disease progression and its relationship with laboratory-clinical findings may be useful in patient triage and symptomatic treatment of patients 32. In this study we used a previously CT score for confirming this presumption, that it was based on the lobar Involvement expanse of as reported by Pan et al 33. The results of the study shown correlation CT scoring with laboratory parameters, age, dyspnea at admission and the presence of pre-existing comorbidities like coronary arteries and diabetes. Information of mortality rate in this study have approved the outstanding importance of age and its rate in patients older than 75 years. our finding in the study substantially assessment CT parenchymal reports and may reflect short and high-term outcome through direct visualization of anatomic damages than with non-specific laboratory parameters and inflammatory biomarkers. Based on clinical criteria provided by the WHO 34 and as expected, finding of this study indicated the correlation of disease severity with CT reports and laboratory parameters, so CT scores were significantly confirmed high correlation between imaging findings and clinical stages, however, the diagnostic role of CT scan and its correlation to laboratory parameters is controversial and debated. Although, the use of CT is as a first line test, but highly sensitive imaging method like CT associated with specific clinical parameters, might be beneficial to speed up diagnostic and therapeutic workflow.