Initial chest radiographs and artificial intelligence (AI) predict clinical outcomes in COVID-19 patients: analysis of 697 Italian patients

Eur Radiol. 2021 Mar;31(3):1770-1779. doi: 10.1007/s00330-020-07269-8. Epub 2020 Sep 18.

Abstract

Objective: To evaluate whether the initial chest X-ray (CXR) severity assessed by an AI system may have prognostic utility in patients with COVID-19.

Methods: This retrospective single-center study included adult patients presenting to the emergency department (ED) between February 25 and April 9, 2020, with SARS-CoV-2 infection confirmed on real-time reverse transcriptase polymerase chain reaction (RT-PCR). Initial CXRs obtained on ED presentation were evaluated by a deep learning artificial intelligence (AI) system and compared with the Radiographic Assessment of Lung Edema (RALE) score, calculated by two experienced radiologists. Death and critical COVID-19 (admission to intensive care unit (ICU) or deaths occurring before ICU admission) were identified as clinical outcomes. Independent predictors of adverse outcomes were evaluated by multivariate analyses.

Results: Six hundred ninety-seven 697 patients were included in the study: 465 males (66.7%), median age of 62 years (IQR 52-75). Multivariate analyses adjusting for demographics and comorbidities showed that an AI system-based score ≥ 30 on the initial CXR was an independent predictor both for mortality (HR 2.60 (95% CI 1.69 - 3.99; p < 0.001)) and critical COVID-19 (HR 3.40 (95% CI 2.35-4.94; p < 0.001)). Other independent predictors were RALE score, older age, male sex, coronary artery disease, COPD, and neurodegenerative disease.

Conclusion: AI- and radiologist-assessed disease severity scores on CXRs obtained on ED presentation were independent and comparable predictors of adverse outcomes in patients with COVID-19.

Trial registration: ClinicalTrials.gov NCT04318366 ( https://clinicaltrials.gov/ct2/show/NCT04318366 ).

Key points: • AI system-based score ≥ 30 and a RALE score ≥ 12 at CXRs performed at ED presentation are independent and comparable predictors of death and/or ICU admission in COVID-19 patients. • Other independent predictors are older age, male sex, coronary artery disease, COPD, and neurodegenerative disease. • The comparable performance of the AI system in relation to a radiologist-assessed score in predicting adverse outcomes may represent a game-changer in resource-constrained settings.

Keywords: Artificial intelligence; COVID-19; Prognosis; Radiography; Severe acute respiratory syndrome.

MeSH terms

  • Age Factors
  • Aged
  • Artificial Intelligence
  • COVID-19 / diagnostic imaging*
  • COVID-19 / epidemiology
  • COVID-19 / mortality
  • COVID-19 / physiopathology
  • Comorbidity
  • Coronary Artery Disease / epidemiology
  • Deep Learning*
  • Emergency Service, Hospital
  • Female
  • Hospitalization
  • Humans
  • Intensive Care Units / statistics & numerical data*
  • Italy / epidemiology
  • Male
  • Middle Aged
  • Mortality
  • Neurodegenerative Diseases / epidemiology
  • Prognosis
  • Proportional Hazards Models
  • Pulmonary Disease, Chronic Obstructive / epidemiology
  • Radiography
  • Radiography, Thoracic*
  • Retrospective Studies
  • SARS-CoV-2
  • Severity of Illness Index
  • Sex Factors
  • Tomography, X-Ray Computed

Associated data

  • ClinicalTrials.gov/NCT04318366