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

Abstract

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.

Keywords: COVID-19; Prospective; Radiology; Surveys and questionnaires; Tomography; X-Ray computed.

Fig. 1

Flowchart of the study shows the number of participating imaging centers. Note: Data are absolute numbers rounded to the nearest decimal

Fig. 2

The variation of the CT_covid rate during the study within the three types of radiology centers. The histogram illustrates the quantitative numbers of CT performed. The lines illustrate the variation of the mean COVID CT rate among the three types of radiology centers. The number of CT_chest and COVID CT_covid seemed to evolve during the study according to the type of centers, whereas in the university hospital, the highest activity was recorded on week 13, it was on week 14 for the public hospital, and on week 15 for the private structure

Fig. 3

Graphic analysis of the COVID-19 in France during the study using choropleth maps. a–d COVID CT rate in France using administrative area as unit according to time. A red unit represents a high COVID-19 CT rate level and a yellow unit a low level. COVID CT rate is highest in the north and east of France and diffused during the 4 weeks of the study. Considering that the epidemic peak was on the week 13, COVID CT rate remains high during the 4 weeks of the study. a CT_covid rate for week 12. b CT_covid rate for week 13. c CT_covid rate for week 14. d CT_covid rate for week 15