Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV–2) is a new virus recently isolated from humans. This new virus is a betacoronavirus that belongs to the Orthocoronavirinae subfamily of the Coronaviridae family [1, 2]. SARS-CoV–2 was discovered to be the pathogen responsible for a cluster of pneumonia associated with severe respiratory disease occurred in December 2019 in China, in Wuhan (the capital of the province of Hubei) [1]. This novel pulmonary infection, formally called Coronavirus Disease 2019 (COVID–19) [3], has spread rapidly in many other Chinese provinces and beyond [2, 4].
On 21 February 2020, SARS-CoV–2 infection was also detected in Northern Italy. Since then, the number of SARS-CoV–2 infection cases has grown exponentially. On 8 March 2020, the number of Italians with SARS-CoV–2 infection was 7375 with a 48% hospitalization rate (18% in intensive care unit) and a 5% mortality rate.
At present, the reference standard to make a definitive diagnosis of SARS-CoV–2 infection is the reverse-transcription-polymerase-chain-reaction assay [5].
Radiological imaging plays a crucial role in the detection and management of COVID–19 patients. Computed tomography (CT) imaging is considered the most effective method for detection of lung abnormalities, particularly in the early stage of disease [4, 6–12]. Moreover, serial chest CT imaging with different time intervals (from three to seven days) is also effective to assess the disease evolution (from initial diagnosis of COVID–19 to patient discharge) [6, 7, 13].
However, the increasing number of hospitalized patients and the consequent increase of radiological examinations make the constant use of chest CT scan (from diagnosis to discharge) difficult to sustain over time. Therefore, in our Radiology Department we are trying to limit the use of CT imaging for monitoring patients with confirmed infection.
Although chest x-ray (CXR) is considered not sensitive for the detection of pulmonary involvement in early-stage disease [4, 14], we believe that, in the current emergency setting, CXR (standard or beside) can be a useful diagnostic tool for monitoring (“day after day”) the rapid progression of lung abnormalities in COVID–19, particularly in critical patients admitted to intensive care units.
The radiological quantification of severity and progression of lung abnormalities is of great importance to define the appropriate clinical management and respiratory support for infected patients. At the present time, two different CT scoring systems and one CXR scoring system were used to quantify the pulmonary involvement in COVID–19 infection [6, 7,11]. This CXR scoring system is a simple five-point grading tool that was proposed in 2015, and it was designed for non-radiologist clinicians [15]. The goal of this scoring system was to facilitate the clinical grading of CXR reports into five different severity categories in hospitalized patients with acute respiratory infection.
Therefore, to the best of our knowledge, there are no published papers in which a dedicated CXR grading system for COVID–19 pneumonia has been designed for radiologists.
The aim of this short communication is to present our experimental CXR scoring system that we are applying in hospitalized patients with COVID–19 pneumonia. We also assessed the validity of this CXR scoring system on a sample of 100 hospitalized patients with SARS-CoV–2 infection for whom the final outcome (recovery or death) was available