Background Coronavirus disease 2019 (COVID-19) is a highly infectious disease caused by the new coronavirus. Previous studies have shown that the chest CT examination plays an important role in the diagnosis and monitoring of COVID-19. However, some patients with COVID-19 had low white blood cell counts and reduced lymphocyte ratios. Multiple CT examinations may cause radiation damages as well as increase the apoptosis of peripheral blood lymphocytes. A new low-dose CT method should be developed because the regular CT may aggravate the disease. Method Sixty cases were randomly divided into the study group ( n = 30) and control group (n = 30). The lung window was reconstructed by Karl 3D iterative technique in the study group. The image quality was subjectively evaluated by two senior chest group diagnostic physicians using a 5-point double-blind method. The value of CT measurement and its standard deviation (SD) was used as an objective evaluation criteria. The volume of CT dose index (CTDI vol ), dose length product (DLP) and effective dose (ED) from the two groups were compared and analyzed statistically. Result There was no significant difference in the occurrence rates of ground glass opacities, consolidation, crazy-paving pattern, fiber cable shadow and axial interstitial thickening between the study group and control group ( p > 0.05). In addition, no significant difference was found for the subjective score of overall image quality and image noise level (SD) between the two groups ( p > 0.05). However, significant differences was found in CTDI vol , DLP, and ED between the study group and the control group ( p < 0.05 ). The effective dose of the study group was reduced by 76% compared to the control group. Conclusion CareDose 4D low-dose scanning combined with Karl 3D iterative reconstruction technology can not only greatly reduce the radiation dose, but also provide images that meet the diagnostic criteria of COVID-19, which can be used as a routine method for the follow-up of COVID-19 patients.
【저자키워드】 Radiation dose, CareDose 4D, Image quality, 【초록키워드】 COVID-19, coronavirus disease, Radiation dose, Image quality, Apoptosis, Coronavirus disease 2019, coronavirus, Lymphocytes, Infectious disease, Peripheral blood, lymphocyte, White blood cell, low-dose, Chest, ground glass opacities, Follow-up, consolidation, COVID-19 patients, New coronavirus, dose, effective dose, blood cell, can not, interstitial thickening, Diagnostic Criteria, Volume, Standard deviation, significant difference, control group, two groups, study group, 5-point double-blind method, axial interstitial thickening, CareDose 4D low-dose scanning, chest CT examination, crazy-paving pattern, CT dose index, CT measurement, dose length product, fiber cable shadow, Karl 3D iterative reconstruction technology, Karl 3D iterative technique, low white blood cell counts, lung window, Multiple CT examinations, new low-dose CT method, no significant difference, peripheral blood lymphocytes, Previous studies, radiation damages, reduced lymphocyte ratios, regular CT, significant differences, previous study, occurrence rate, effective, evaluation criteria, Result, shown, was used, caused, addition, evaluated, can be used, two group, iterative, reconstructed, was reduced, statistically, greatly reduce, aggravate the disease, compared and analyzed, diagnosis and monitoring, diagnostic physician, DLP, Karl 3D, low-dose CT method, low-dose scanning, Multiple CT examination, noise level, patients with COVID-19, radiation damage, randomly divided, the study group, 【제목키워드】 COVID-19, Computed tomography, low dose, Follow-up, application, Karl 3D technology,