Estimation of Radiation Dose Parameters of High-Resolution Computed Tomography Chest Examination for COVID-19 Patients: A Retrospective Study

During the COVID-19 pandemic, high-resolution computed tomography chest examination was widely used to diagnose the coronavirus disease. Thus, radiation dose optimization is an essential requirement to decrease the risk of radiation hazards. This study aimed to estimate the radiation dose parameters of high-resolution computed tomography chest examination of COVID-19 patients using automatic tube current modulation technique and compare the values with various standard diagnostic reference levels (DRLs) available in the literature. It is a retrospective study conducted on 205 patients with COVID-19, including 144 males and 61 females with a median age of 49 years. All patients with clinical and positive laboratory findings were confirmed by an RT-PCR test. The data were collected from the Department of Radiodiagnosis Government Base Hospital Almora (Uttarakhand) from September 2020 to May 2021. All patients underwent high-resolution computed tomography chest examination with an automatic tube current modulation technique. Radiation dose parameters, such as Volume Computed Tomography Dose Index (CTDIvol) and Dose Length Product (DLP), were extracted from the dose report, and Effective dose (ED) was calculated. The mean volume computed tomography dose index, dose length product, and effective dose were 4.36 mGy, 136.29 mGy.cm, and 1.8mSv respectively. Volume computed tomography dose index and dose length product values at the 75th percentile were well below the various DRLs, which confirmed the usefulness of the automatic tube current modulation technique in high-resolution computed tomography (HRCT) of the chest for dose optimization at 120 kV.