COVID-19 impact assessment on the French radiological centers: a nationwide survey

PURPOSE: To determine the impact of the COVID-19 on the CT activities in French radiological centers during the epidemic peak. MATERIALS AND METHODS: A cross-sectional prospective CT scan survey was conducted between March 16 and April 12, 2020, in accordance with the local IRB. Seven hundred nine radiology centers were invited to participate in a weekly online survey. Numbers of CT examinations related to COVID-19 including at least chest (CT(covid)) and whole chest CT scan activities (CT(chest)) were recorded each week. A sub-analysis on French departments was performed during the 4 weeks of the study. The impact of the number of RT-PCRs (reverse transcriptase polymerase chain reactions) on the CT workflow was tested using two-sample t test and Pearson’s test. RESULTS: Five hundred seventy-seven structures finally registered (78%) with mean response numbers of 336 ± 18.9 (323; 351). Mean CT(chest) activity per radiologic structure ranged from 75.8 ± 133 (0–1444) on week 12 to 99.3 ± 138.6 (0–1147) on week 13. Mean ratio of CT(covid) on CT(chest) varied from 0.36 to 0.59 on week 12 and week 14 respectively. There was a significant relationship between the number of RT-PCR performed and the number of CT(covid) (r = 0.73, p = 3.10(−16)) but no link with the number of positive RT-PCR results. CONCLUSION: In case of local high density COVID-19, CT workflow is strongly modified and redirected to the management of these specific patients. KEY POINTS: • Over the 4-week survey period, 117,686 chest CT (CT (total) ) were performed among the responding centers, including 61,784 (52%) CT performed for COVID-19 (CT (covid) ). • Across the country, the ratio CT(covid)/CT(total) varied from 0.36 to 0.59 and depended significantly on the local epidemic density (p = 0.003). • In clinical practice, in a context of growing epidemic, in France, chest CT was used as a surrogate to RT-PCR for patient triage. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s00330-020-07035-w) contains supplementary material, which is available to authorized users.