Correlation Between Low-Dose Chest Computed Tomography and RT-PCR Results for the Diagnosis of COVID-19: A Report of 27,824 Cases in Tehran, Iran

Abstract

Rationale and Objectives Real-time polymerase chain reaction (RT-PCR) remains the gold standard for confirmation of Coronavirus disease 2019 (COVID-19) despite having many disadvantages. Here, we investigated the diagnostic performance of chest computed tomography (CT) as an alternative to RT-PCR in patients with clinical suspicion of COVID-19 infection. Methods In this descriptive cross-sectional study, 27824 patients with clinical suspicion of COVID-19 infection who underwent unenhanced low-dose chest CT from 20 February, 2020 to 21 May, 2020 were evaluated. Patients were recruited from seven specifically designated hospitals for patients with COVID-19 infection affiliated to Shahid Beheshti University of Medical Sciences. In each hospital, images were interpreted by two independent radiologists. CT findings were considered as positive/negative for COVID-19 infection based on RSNA diagnostic criteria. Then, the correlation between the number of daily positive chest CT scans and number of daily PCR-confirmed cases and COVID-19-related deaths in Tehran province during this three-month period was assessed. The trends of admission rate and patients with positive CT scans were also evaluated. Results A strong positive correlation between the numbers of daily positive CT scans and daily PCR-confirmed COVID-19 cases (r=0.913, p < 0.001) was observed. Furthermore, in hospitals located in regions with a lower socioeconomic status, the admission rate and number of positive cases within this three-month period was higher as compared to other hospitals. Conclusion Low-dose chest CT is a safe, rapid and reliable alternative to RT-PCR for the diagnosis of COVID-19 in high-prevalence regions. In addition, our study provides further evidence for considering patients’ socioeconomic status as an important risk factor for COVID-19.

Differentiation of Chest CT Findings Between Influenza Pneumonia and COVID-19: Interobserver Agreement Between Radiologists

“…RT-PCR as a laboratory technique and confirmed one is not empty of false-negative reports according to numerous reasons ( 23 ). Therefore, in those highly suspicious patients with negative RT-PCR results, thin-section CT features could be considered as paramount guidance ( 10 , 24 , 25 ). On the other hand, according to seasonal climate changes, respiratory tract viruses such as influenza and respiratory syncytial viruses tend to involve bronchus, lung parenchyma, and also pleura.…”

Novel multi-site graph convolutional network with supervision mechanism for COVID-19 diagnosis from X-ray radiographs

“…To this end, many researchers utilized the findings from medical imaging techniques (X-ray and computed tomography (CT)) to early diagnose the suspected COVID-19 cases and other lung diseases as well [10] . In fact, these techniques, particularly CT, have demonstrated to be an effective and fast alternative to the RT-PCR with high detection accuracy [7] , [11] . In addition, imaging data can be stored for disease follow-up measurements.…”

Can laboratory parameters be an alternative to CT and RT‐PCR in the diagnosis of COVID‐19? A machine learning approach

“…Zali et al reported that CT scans are safer, faster, and more reliable than RT‐PCR for the diagnosis of COVID‐19 in regions with a high prevalence of the disease 12 . Kayaaslan et al investigated the effectiveness of the second RT‐PCR test in patients with suspected COVID‐19 whose first test was negative.…”

“…Zali et al reported that CT scans are safer, faster, and more reliable than RT‐PCR for the diagnosis of COVID‐19 in regions with a high prevalence of the disease. 12 Kayaaslan et al investigated the effectiveness of the second RT‐PCR test in patients with suspected COVID‐19 whose first test was negative. As a result, they reported that the second RT‐PCR test was a waste of labor and time, its additional contribution to the first test was very low, and that it was costly.…”