 ical  Imaging     Send Orders for Reprints to reprints@benthamscience.net 38 Current Medical Imaging, 2022, 18, 38-44 RESEARCH ARTICLE The Feasibility of Low-dose Chest CT Acquisition Protocol for the Imaging of COVID-19 Pneumonia Eray Atlı 1,* , Sadık Ahmet Uyanık 1 , Umut Öğüşlü 1 , Halime Çevik Cenkeri 1 , Birnur Yılmaz 1 and Burçak Gümüş 1 1 Department of Radiology, İstanbul Okan University Hospital, Tuzla/İstanbul, Turkey ARTICLE HISTORY Received: November 03, 2020 Revised: March 25, 2021 Accepted: April 08, 2021 DOI: 10.2174/1573405617666210623124108 Abstract: Objective: This study aimed to investigate the feasibility of low-dose chest CT acquisi- tion protocol for the imaging of COVID 19 disease or suspects of this disease in adults. Methods: In this retrospective case-control study, the study group consisted of 141 patients who were imaged with low dose chest CT acquisition protocol. The control group consisted of 92 pa- tients who were imaged with standard protocol. Anteroposterior and lateral diameters of chest, ef- fective diameter and scan length, qualitative and quantitative noise levels, volumetric CT Dose In- dex (CTDI vol ), Dose Length Product (DLP), and size-specific dose estimations were compared be- tween groups. Results: Radiation dose reduction by nearly 90% (CTDI vol and DLP values 1.06 mGy and 40.3 mGy.cm vs. 8.07 mGy and 330 mGy.cm, respectively; p < 0.001) was achieved with the use of low-dose acquisition chest CT protocol. Despite higher image noise with low-dose acquisition pro- tocol, no significant effect on diagnostic confidence was encountered. Cardiac and diaphragm movement-related artifacts were similar in both groups (p=0.275). Interobserver agreement was very good in terms of diagnostic confidence assessment. Conclusion: For the imaging of COVID-19 pneumonia or suspects of this disease in adults, low- dose chest CT acquisition protocol provides remarkable radiation dose reduction without adversely affecting image quality and diagnostic confidence. Keywords: Chest CT, COVID-19, CTDI vol , DLP, low dose, pneumonia, radiation protection. 1. INTRODUCTION Coronavirus disease 2019 (COVID-19) is a mainly respi- ratory infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and was first report- ed as an outbreak in Wuhan, China in December 2019. With the transcontinental spread of the disease, on March 11, 2020, World Health Organization (WHO) accepted this in- fection as a pandemic [1-4]. COVID-19 is mainly manifest- ed by systemic and/or respiratory symptoms [5]. Since there is a lack of particular treatment or vaccines for COVID-19, the primarily effective method to manage the disease is to de- tect infected individuals as early as possible and promptly isolate the infected individuals from the community. The gold standard in the diagnosis of COVID-19 is Reverse Tran- scriptase Polymerase Chain Reaction (RT-PCR), which can be sampled by throat swab and is highly specific. The sensi- tivity of RT-PCR has been reported 71% by Fang et al. [6], which is quite low for monitoring. Due to low sensitivity, *Address correspondence to this author at the Department of Radiology, İs- tanbul Okan University Hospital, Tuzla/İstanbul, Turkey; Tel: +902164946526; Fax: +908507379863; E-mail: atlieray@gmail.com negative RT-PCR does not rule out COVID-19, and recur- rent tests may be required for the definitive diagnosis. In such a rapidly progressive pandemic, the main disadvantage of this gold standard test is that it causes ambiguity for healthcare professionals and patients if the result of the test is negative. Delay in diagnosis and treatment of the COVID-19 have the potential risk of spreading the SARS- CoV-2 to a larger population. Chest computed tomography (CT) is another essential tool in both diagnosis and evaluation of the clinical severity of COVID-19 [7]. Dangis et al. [8] reported that low-dose chest CT has high sensitivity and specificity in the diagnosis of COVID-19 as compared to RT-PCR. Radiological find- ings related to COVID 19 disease frequently involve lung parenchyma, which can be easily detected in chest CT, and have been reported by previous studies in the literature [8-11]. In addition, Ai et al. [12] have reported that chest CT has a high sensitivity for the diagnosis of COVID-19 pneu- monia and proposed that in epidemic regions for patients with a high probability of disease, chest CT should be con- sidered for screening and follow-up. In such a pandemic where a large portion of the population is likely to be affect- ed, X-ray exposure, the limiting feature of CT scanning, be- 1 7 - /22 $65.00+.00 © 2022 Bentham Science Publishers