Journal Article

Simulated low-dose dark-field radiography for detection of COVID-19 pneumonia

Fingerle, Alexander A., Bast, Henriette, Frank, Manuela, Karrer, Alexandra, Renger, Bernhard, Pfeiffer, Franz, Urban, Theresa, Gassert, Florian T., Schick, Rafael C., Sauter, Andreas P., Makowski, Marcus R., Koehler, Thomas, Pfeiffer, Daniela

2024

Overview

Dark-field radiography has been proven to be a promising tool for the assessment of various lung diseases. To evaluate the potential of dose reduction in dark-field chest radiography for the detection of the Coronavirus SARS-CoV-2 (COVID-19) pneumonia. Patients aged at least 18 years with a medically indicated chest computed tomography scan (CT scan) were screened for participation in a prospective study between October 2018 and December 2020. Patients were included if they had a CO-RADS (COVID-19 Reporting and Data System) score ≥ 4 (COVID-19 group) or if they had no pathologic lung changes (controls). A total of 89 participants with a median age of 60 years (interquartile range 48 to 68 yrs.) were included in this study. Dark-field and attenuation-based radiographs were simultaneously obtained by using a prototype system for dark-field radiography. By modifying the image reconstruction algorithm, low-dose radiographs were simulated based on real participant images. The simulated radiographs corresponded to 50%, 25%, and 13% of the full dose (41.9 μSv, median value). Four experienced radiologists served as blinded readers assessing both image modalities, displayed side by side in random order. The presence of COVID-19-associated lung changes was rated on a scale from 1 to 6. The readers' diagnostic performance was evaluated by analyzing the area under the receiver operating characteristic curves (AUC) using Obuchowski's method. Also, the dark-field images were analyzed quantitatively by comparing the dark-field coefficients within and between the COVID-19 and the control group. The readers' diagnostic performance in the image evaluation, as described by the AUC value (where a value of 1 corresponds to perfect diagnostic accuracy), did not differ significantly between the full dose images (AUC = 0.86) and the simulated images at 50% (AUC = 0.86) and 25% of the full dose(AUC = 0.84) (p>0.050), but was slightly lower at 13% dose (AUC = 0.82) (p = 0.038). For all four radiation dose levels, the median dark-field coefficients within groups were identical but different significantly by 15% between the controls and the COVID-19 pneumonia group (p<0.001). Dark-field imaging can be used to diagnose the Coronavirus SARS-CoV-2 (COVID-19) pneumonia with a median dose of 10.5 μSv, which corresponds to 25% of the original dose used for dark-field chest imaging.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Aged / Algorithms / Bacterial pneumonia / Betacoronavirus / Chest / Computed tomography / Consent / Coronavirus Infections - diagnosis / Coronavirus Infections - diagnostic imaging / Coronaviruses / COVID-19 / COVID-19 - diagnostic imaging / Data systems / Diagnosis / Emphysema / Female / Humans / Image processing / Image reconstruction / Lung - diagnostic imaging / Lung diseases / Male / Medical imaging / Methods / Middle Aged / Pandemics / Performance evaluation / Pneumonia / Pneumonia, Viral - diagnostic imaging / Pneumothorax / Prospective Studies / Radiation / Radiation Dosage / Radiographs / Radiography / Radiography, Thoracic - methods / ROC Curve / SARS-CoV-2 / Scanners / Severe acute respiratory syndrome coronavirus 2 / Tomography, X-Ray Computed - methods / X-rays