REVIEW Open Access A review on chest CT scanning parameters implemented in COVID-19 patients: bringing low-dose CT protocols into play Javid Azadbakht 1 , Daryoush Khoramian 2 , Zahra Sadat Lajevardi 3 , Fateme Elikaii 3 , Amir Hossein Aflatoonian 3 , Bagher Farhood 4* , Masoud Najafi 5* and Hamed Bagheri 6 Abstract Background: This study aims to review chest computed tomography (CT) scanning parameters which are utilized to evaluate patients for COVID-19-induced pneumonia. Also, some of radiation dose reduction techniques in CT would be mentioned, because using these techniques or low-dose protocol can decrease the radiation burden on the population. Main body: Chest CT scan can play a key diagnostic role in COVID-19 patients. Additionally, it can be useful to monitor imaging changes during treatment. However, CT scan overuse during the COVID-19 pandemic raises concerns about radiation-induced adverse effects, both in patients and healthcare workers. Conclusion: By evaluating the CT scanning parameters used in several studies, one can find the necessity for optimizing these parameters. It has been found that chest CT scan taken using low-dose CT protocol is a reliable diagnostic tool to detect COVID-19 pneumonia in daily practice. Moreover, the low-dose chest CT protocol results in a remarkable reduction (up to 89%) in the radiation dose compared to the standard-dose protocol, not lowering diagnostic accuracy of COVID-19-induced pneumonia in CT images. Therefore, its employment in the era of the COVID-19 pandemic is highly recommended. Keywords: COVID-19 pneumonia, Computed tomography, Radiation dose, Low dose Background New coronavirus (commonly known as COVID-19) pneumonia, which was first reported in Wuhan, Hubei Province, China, in December 2019, followed rapid spread across China and worldwide [1]. This virus is highly contagious and can be spread from person to per- son by either an infected person or an asymptomatic carrier. The virus can spread in communities and cross borders rapidly. Respiratory droplets (in most of the cases), close contact, and transmission via the digestive tract are possible routes of transmission [2, 3]. Thus far, no curative drug or effective vaccine for COVID-19 is available; therefore, diagnosing the disease at an early stage and to quarantine the infected patients are the most rational approaches to alleviate. China government has published a guideline on Diagnosis and Treatment of Pneumonitis Caused by 2019-nCoV; its latest version says reverse transcription-polymerase chain reaction (RT-PCR) or gene sequencing for samples extracted from the respiratory tract or blood is needed to confirm the diagnosis of COVID-19, which in turn is the main indicator of the need for hospitalization [4]. Though, limitations related to kit performance, sample extraction and sample transportation resulted in about 30 to 60% of RT-PCR tests done on throat swab samples to be positive at initial presentation. This lack of sensitivity © The Author(s). 2021 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. * Correspondence: bffarhood@gmail.com; najafi_ma@yahoo.com 4 Department of Medical Physics and Radiology, Kashan University of Medical Sciences, Kashan, Iran 5 Radiology and Nuclear Medicine Department, School of Paramedical Sciences, Kermanshah University of Medical Sciences, Kermanshah, Iran Full list of author information is available at the end of the article Egyptian Journal of Radiology and Nuclear Medicine Azadbakht et al. Egyptian Journal of Radiology and Nuclear Medicine (2021) 52:13 https://doi.org/10.1186/s43055-020-00400-1