Radiation dose levels in chest computed tomography scans of coronavirus disease 2019 pneumonia: A survey of 2119 patients in Chongqing, southwest China.

ABSTRACT: To investigate computed tomography (CT) diagnostic reference levels for coronavirus disease 2019 (COVID-19) pneumonia by collecting radiation exposure parameters of the most performed chest CT examinations and emphasize the necessity of low-dose CT in COVID-19 and its significance in radioprotection.The survey collected RIS data from 2119 chest CT examinations for 550 COVID-19 patients performed in 92 hospitals from January 23, 2020 to May 1, 2020. Dose data such as volume computed tomography dose index, dose-length product, and effective dose (ED) were recorded and analyzed. The radiation dose levels in different hospitals have been compared, and average ED and cumulative ED have been studied.The median dose-length product, volume computed tomography dose index, and ED measurements were 325.2 mGy cm with a range of 6.79 to 1098 mGy cm, 9.68 mGy with a range of 0.62 to 33.80 mGy, and 4.55 mSv with a range of 0.11 to 15.37 mSv for COVID-19 CT scanning protocols in Chongqing, China. The distribution of all observed EDs of radiation received by per patient undergoing CT protocols during hospitalization yielded a median cumulative ED of 17.34 mSv (range, 2.05-53.39 mSv) in the detection and management of COVID-19 patients. The average number of CT scan times for each patient was 4.0 ±â€Š2.0, and the average time interval between 2 CT scans was 7.0 ±â€Š5.0 days. The average cumulative ED of chest CT examinations for COVID-19 patients in Chongqing, China greatly exceeded public limit and the annual dose limit of occupational exposure in a short period.For patients with known or suspected COVID-19, a chest CT should be performed on the principle of rapid-scan, low-dose, single-phase protocol instead of routine chest CT protocol to minimize radiation doses and motion artifacts.

[Effect of A High Intensive Preoperative Rehabilitation on the Perioperative 
Complications in Patients with Chronic Obstructive Pulmonary Disease Eligible 
for Lung Cancer Surgery].

BACKGROUND: Chronic obstructive pulmonary disease (COPD) will reduce the cardiopulmonary function and increase perioperative risk. The aim of this study is to investigate the effect of preoperative short-term high intensity lung rehabilitation training on lung function and postoperative complications in patients with COPD who are eligible for lung cancer surgery. METHODS: We analysis of 101 patients with COPD and a diagnosis of lung cancer, with 43 patients in pulmonary rehabilitation group and 58 patients in conventional group. The pulmonary function, postoperative pulmonary complications (PPCs) and length of stay (LOS) will be compared between the two groups, the lung function will be compared before and after the rehabilitation at the same time. RESULTS: There were no significant difference between the two groups in general information, lung function before surgery, postoperative pulmonary infection [8 (18.6%) vs 17 (29.3%)], atelectasis [1 (2.3%) vs 1 (1.7%)], respiratory failure [1 (2.3%) vs 2 (3.4%)] and postoperative LOS [(8.93±3.78) d vs (9.62±3.98) d, P>0.05]. In the rehabilitation group, the FEV1 [(2.06±0.45) L vs (2.15±0.45) L, P<0.001] and PEF [(4.32±0.90) L/s vs (5.15±1.05) L/s, P<0.001) were higher, and PCO2 [(42.42±2.79) mmHg vs (41.58±2.98) mmHg, P=0.009] was lower after rehabilitation, significantly. The increase value of FEV1 in moderate to severe COPD group was higher than that of the mild COPD group after the rehabilitation [(0.16±0.05) L, 8.6% vs (0.06±0.05) L, 2.8%, P<0.001). CONCLUSIONS: The short-term highly-intensity lung rehabilitation can improve lung function in lung cancer patients with COPD, and the improvement of pulmonary function in moderate to severe COPD patients is more obviously.