DIAGNOSTIC IMPACT OF BEDSIDE CHEST X-RAY FEATURES OF 2019 NOVEL CORONAVIRUS IN THE ROUTINE ADMISSION AT THE EMERGENCY DEPARTMENT: CASE SERIES FROM LOMBARDY REGION

Davide, Ippolito; Pecorelli, Anna; Maino, Cesare; Capodaglio, Carlo; Mariani, Ilaria; Giandola, Tersa; Gandola, Davide; Bianco, Ilaria; Ragusi, Maria; Cammillo, Talei Franzesi; Corso, Rocco; Sandro, Sironi

PURPOSE: To evaluate the diagnostic accuracy and the imaging features of routine admission chest X-ray in patients suspected for novel Coronavirus 2019 (SARS-CoV-2) infection. METHOD: We retrospectively evaluated clinical and X-ray features in all patients referred to the emergency department for suspected SARS-CoV-2 infection between March 1(st) and March 13(th). A single radiologist with more than 15 years of experience in chest-imaging evaluated the presence and extent of alveolar opacities, reticulations, and/or pleural effusion. The percentage of lung involvement (range <25% to 75-100%) was also calculated. We stratified patients in groups according to the time interval between symptoms onset and X-ray imaging (≤ 5 and > 5 days) and according to age (≤ 50 and > 50 years old). RESULTS: A total of 518 patients were enrolled. Overall 314 patients had negative and 204 had positive RT-PCR results. Lung lesions in patients with SARS-Cov2 pneumonia primarily manifested as alveolar and interstitial opacities and were mainly bilateral (60.8%). Lung abnormalities were more frequent and more severe by symptom duration and by increasing age. The sensitivity and specificity of chest X-ray at admission in the overall cohort were 57% (95% CI = 47-67) and 89% (83-94), respectively. Sensitivity was higher for patients with symptom onset > 5 days compared to ≤ 5 days (76% [62-87] vs 37% [24-52]) and in patients > 50 years old compared to ≤ 50 years (59% [48-69] vs 47% [23-72]), at the expense of a slightly lower specificity (68% [45-86] and 82% [73-89], respectively). CONCLUSIONS: Overall chest X-ray sensitivity for SARS-CoV-2 pneumonia was 57%. Sensitivity was higher when symptoms had started more than 5 days before, at the expense of lesser specificity, while slightly higher in older patients in comparison to younger ones.