A phantom study to optimise the automatic tube current modulation for chest CT in COVID-19

European Radiology Experimental

Jenia Vassileva¹  Victor Gombolevskiy²  Valeria Chernina²  Ivan Blokhin²  Sergey Morozov² 

[1] Radiation Protection of Patients Unit, International Atomic Energy Agency, Vienna, Austria;Research and Practical Clinical Center for Diagnostics and Telemedicine Technologies of the Moscow Health Care Department, Moscow, Russian Federation;

关键词: Multidetector computed tomography;    Phantoms (imaging);    Radiation protection;    SARS-CoV-2 infection;   

DOI  :  10.1186/s41747-021-00218-0

来源: Springer

【 摘 要 】

On March 11, 2020, the World Health Organization declared the coronavirus disease 2019 (COVID-19) pandemic. The expert organisations recommend more cautious use of thoracic computed tomography (CT), opting for low-dose protocols. We aimed at determining a threshold value of automatic tube current modulation noise index below which there is a chance to miss an onset of ground-glass opacities (GGO) in COVID-19. A team of radiologists and medical physicists performed 25 phantom CT studies using different automatic tube current modulation settings (SUREExposure3D technology). We then conducted a retrospective evaluation of the chest CT images from 22 patients with COVID-19 and calculated the density difference between the GGO and unaffected tissue. Finally, the results were matched to the phantom study results to determine the minimum noise index threshold value. The minimum density difference at the onset of COVID-19 was 252 HU (p < 0.001). This was found to correspond to the SUREExposure 3D noise index of 36. We established the noise index threshold of 36 for the Canon scanner without iterative reconstructions, allowing for a decrease in the dose-length product by 80%. The proposed protocol needs to be validated in a prospective study.

【 授权许可】

CC BY