Application of chest low-dose CT screening of Corona Virus Disease 2019 with a third-generation dual-source scanner

Objective: To investigate the application value of third-generation dual-source CT(3-G DSCT) low-dose scan mode combined with iterative reconstruction technology in the screening of COVID-19 and to evaluate the radiation dose Methods: One hundred and twenty patients suspected of COVID-19 from December 2019 to February 2020 were retrospectively analysed and randomly divided into two groups (test group and conventional group, 60 patients in each) The parameters for test group included 3-G DSCT, Turbo Flash scan mode, CARE kV, with reference 90 kV, pitch 2 0, and ADMIRE algorithm, while those parameters for conventional group included the 128-slice CT, conventional spiral scan mode, 120 kV, pitch 1 2, and FBP algorithm The CT values of aorta, spinal posterior muscle, and subcutaneous fat, the aortic noise, signal-to-noise ratio (SNR), and contrast noise ratio (CNR) were compared to evaluate the image quality between two groups Two experienced doctors scored the image quality using a double-blind method, and compared the CT dose index volume (CTDIvol), dose-length product (DLP), and effective dose (E) of the two groups Results: The CT value of the aorta and spinal posterior muscle and the aortic SNR in the test group were (45 38±4 77), (53 41±8 44) HU, and 2 82±0 59, and significantly higher than those in the conventional group [(39 68±6 26), (42 66±6 32) HU, 2 58±0 61, t=5 608, 7 897, 2 162, P 0 05) The CTDIvol, DLP, and E in the test group were (3 09±1 02) mGy, (107 57±32 81) mGy•cm, (1 51±0 46) mSv, significantly lower than those in the conventional group [(7 00±1 80) mGy, (261 65±73 93) mGy•cm, (3 66±1 03) mSv;t=-14 680, -14 756, -14 756, P<0 05] Conclusions: In the screening of COVID-19, using low-dose scanning mode of 3-G DSCT combined with iterative reconstruction technology would provide diagnostic quality images and meanwhile effectively reduce the radiation dose and improve the SNR of the image Copyright © 2020 by the Chinese Medical Association