Radiographers and COVID-19 pneumonia: Diagnostic performance using CO-RADS

Introduction: A more structured role of radiographers is advisable to speed up the management of patients with suspected COVID-19. The purpose of our study was to evaluate the diagnostic performance of radiographers in the detection of COVID-19 pneumonia on chest CT using CO-RADS descriptors.

Methods: CT images of patients who underwent RT-PCR and chest CT due to COVID-19 suspicion between March and July 2020 were analysed retrospectively. Six readers, including two radiologists, two highly experienced radiographers and two less experienced radiographers, independently scored each CT using the CO-RADS lexicon. ROC curves were used to investigate diagnostic accuracy, and Fleiss'κ statistics to evaluate inter-rater agreement.

Results: 714 patients (419 men; 295 women; mean age: 64 years ±19SD) were evaluated. CO-RADS> 3 was identified as optimal diagnostic threshold. Highly experienced radiographers achieved an average sensitivity of 58.7% (95%CI: 52.5-64.7), an average specificity of 81.8% (95%CI: 77.9-85.2), and a mean AUC of 0.72 (95%CI: 0.68-0.75). Among less experienced radiographers, an average sensitivity of 56.3% (95%CI: 50.1-62.2) and an average specificity of 81.5% (95%CI: 77.6-84.9) were observed, with a mean AUC of 0.71 (95%CI: 0.68-0.74). Consultant radiologists achieved an average sensitivity of 60.0% (95%CI: 53.7-65.8), an average specificity of 81.7% (95%CI: 77.8-85.1), and a mean AUC of 0.73 (95%CI: 0.70-0.77).

Conclusion: Radiographers can adequately recognise the classic appearances of COVID-19 on CT, as described by the CO-RADS assessment scheme, in a way comparable to expert radiologists.

Implications for practice: Radiographers, as the first healthcare professionals to evaluate CT images in patients with suspected SARS-CoV-2 infection, could diagnose COVID-19 pneumonia by means of a categorical reporting scheme at CT in a reliable way, hence playing a primary role in the early management of these patients.