Table 1. Description of VP-RADS Classification (COVID-19 Version) and diagnostic & therapeutic suggestions.

VP-RADS	Definition	Indicator	Imaging reporting and recommendations	Suggestions for clinical management
Category 0	Cannot be classified, defined as uncertain category	CT images cannot be fully recognized or assessed	Technicians should determine immediately whether an additional scan is necessary. For conditions that artifacts cannot be eliminated, an explanation should be presented in the CT report	None
Category 1	cannot be excluded definitely for COVID-19	(I) No acute pulmonary exudative changes detected on chest CT. (II) Ground-glass opacities without any changes for over 2 weeks	If epidemiological history of COVID-19 is confirmed, short-term follow-up should be recommended in the report	Further investigations and treatment should be determined according to the epidemiological history and clinical manifestations
Category 2	COVID-19 contraction can be excluded in most conditions	Acute pulmonary exudation is found on chest CT, combined with clinical manifestations	Imaging features, clinical manifestations and laboratory findings should be taken into account comprehensively. Imaging report should give a definite diagnosis and recommend an appropriate time for follow-up	Appropriate measures should be taken on the basis of etiology, other screening items and a recent chest LDCT should be considered
Category 3	COVID-19 cannot be excluded	Acute pulmonary exudation is found on chest CT without typical imaging findings, without known COVID-19 epidemiological history, and with clear clinical evidences for bacterial pneumonia or other definite pathogenic factors	The reporting should be included in hospital critical values for a timely react, expertise consultation and a LDCT recheck	During the epidemic outbreak, a VP-RADS category 3 patient should receive an emergency consultation by clinical specialists, and the subsequent screening and treatment could be determined afterwards
Category 4	Suggesting a high possibility of COVID-19	Acute pulmonary exudation is found on chest CT, with known COVID-19 epidemiological history and clinical manifestations	Critical values reporting protocols must be adhered and hospital emergency response for prevention and control should be initiated	Activate hospital prevention and treatment expert group for an immediate multi-disciplinary consultation, and take measures afterwards
Category F	Follow-up	Serial chest radiography for confirmed cases	Give an objective assessment on the treatment effect, including disease progression, no significant changes, and absorption	There should be a continuous assessment on therapeutic effect in confirmed cases

LDCT, low-dose CT.