The RACOON Viral Pneumonia Score for structured reporting of preexisting, acute and post-pneumonic findings on chest CT

Thorsten Persigehl¹Philipp Fervers¹Andreas Bucher²Peter Isfort^3,4David Maintz¹Tobias Penzkofer⁵Marwin Sähn³Thomas Vogl²Jonathan Kottlors¹Felix Doellinger^5*

• ¹Faculty of Medicine and University Hospital Cologne, Institute for Diagnostic and Interventional Radiology, Cologne, Germany
• ²Goethe University Frankfurt, Department of Diagnostic and Interventional Radiology, Frankfurt am Main, Germany
• ³University Hospital Aachen, Department of Radiology, Aachen, Germany
• ⁴Hospital Friederikenstift, Department of Radiology, Hannover, Germany
• ⁵Charité Universitätsmedizin Berlin, Department of Radiology, Berlin, Germany

Background: The multi-dimensional RACOON Viral Pneumonia Score (RVPS) was developed to compensate for the main weaknesses of the established one-dimensional chest CT scores: first, to quantify the severity of pneumonia and, second, to qualitatively monitor infectious lung disease from acute stage to post-pneumonic sequelae.Objectives: This research focusses on the original development and evaluation of applicability and inter-reader reliability of the RVPS. Methods: Within the Radiological Cooperative Network (RACOON) the scoring system was developed in several expert meetings and tested in this proof-of-concept study with 8,525 observations. In the subset of inter-reader validation (7,800 observations), eight blinded radiologists applied the RVPS and evaluated the following CT findings for each lung lobe individually: (I) pure ground glass opacities (GGO), (II) GGO and interstitial thickening, (III) consolidations, (IV) linear opacities and reticulations, (V) fibrotic-like changes. The extent of each pathology was scored 0-5 points and the total involvement was calculated. Inter-reader variability was assessed using Kendall's W.Results: This study presents the RVPS as a comprehensive tool for inter-reader reliable evaluation, longitudinal monitoring, and structured documentation of the extent as well as quality of chest CT findings in infectious lung disease. Conclusions: This study presents the RVPS as a comprehensive tool for inter-reader reliable evaluation, longitudinal monitoring, and structured documentation of the extent as well as quality of chest CT findings in infectious lung disease.The Racoon Viral Pneumonia Score (RVPS) is a multidimensional instrument for structured, quantitative and qualitative assessment of (post-)pneumonia CT findings. The RVPS proved robust in multi-center inter-reader evaluation. The RVPS may facilitatesfacilitate the application of artificial intelligence (AI) and represents a tool for pandemic preparedness.