Chest CT utilization in COVID-19: a dosimetric and diagnostic-quality study.

The purpose of this study is to look at the variations in chest computed tomography (CT) use, radiation dose and image quality in the 2019 novel coronavirus (COVID-19) pneumonia patients in Saudi Arabia. This is a retrospective study of 402 patients with COVID-19, who were treated between February and October 2021. Radiation dose was estimated using metrics of volume CT dose index (CTDIvol) and size-specific dose estimate (SSDE). The imaging performance of the CT scanners was evaluated by measuring different parameters, such as resolution and CT number uniformity, with an ACR-CT accreditation phantom. Expert radiologists assessed the diagnostic quality and occurrence of artefacts. For all of the image quality parameters tested, the majority of the scanner sites (80%) were found to be within the suggested acceptance limits. Ground-glass opacities were the most common finding in our patient sample (54%). On chest CT exams with typical appearance of COVID-19 pneumonia, the most respiratory motion artefacts (56.3%) were present, followed by those with indeterminate appearance (32.2%). There were significant differences in CT utilization, CTDIvol and SSDE across the collaborated sites. The use of CT scans and radiation doses varied in the COVID-19 patients, highlighting the optimizations of CT protocols at participating sites.

AUTOMATED ESTIMATION OF PATIENT'S SIZE USING AUTOWED TOOL AND INDOSECT PROGRAM: A DOSIMETRIC STUDY FOR PAEDIATRIC HEAD CT EXAMINATIONS.

Size-specific dose estimate (SSDE), which can be calculated by measuring the effective diameter (De) or water equivalent diameter (Dw) of the patient, is one of the recent approaches for verifying the individual doses during computer tomography (CT) examinations. This work aimed to compare the Dw estimated by the AutoWED tool and IndoseCT software and to investigate CT axial (ARH) and paediatric head (PH) protocols used in southern Saudi Arabia to calculate the dose received by paediatric patients using metrics of volume CT dose index (CTDIvol) and SSDE. The distribution between the ARH and PH protocols was 57.8 and 42.2%, respectively. There was no significant difference in Dw values between the AutoWED tool and the IndoseCT program (0.13%). Including CT table or other objects during estimation of Dw can lead to variation up to 11.4%. The impact of selecting IndoseCT options to identify the border of the patient may be part of the explanation for these variations. A strong linear relationship was obtained between De and Dw in paediatric head size (R2 = 0.96). Using IndoseCT, for 0-1.5, 1.5-5 and 5.0-18 age groups (years), the Dw was found to be 13.2, 15.3 and 16.8 cm, respectively. The SSDE for the PH protocol was substantially lower than that of the ARH protocol. As a result, education of the individuals engaging in paediatric CT examinations is necessary for dose optimization.