Human readout

Seven radiologists (two fellows in thoracic imaging with 5 years of experience and five residents with 2–4 years of experience in general radiology, including at least 1 year of experience in thoracic imaging) independently conducted a blinded retrospective readout. For the readout of the conventional chest radiographs, the radiologists evaluated the radiographs in both planes and subsequently interpreted the posterior-anterior projection with bone subtraction. The readout was performed on a dedicated PACS-workstation (Sectra PACS IDS7, Sectra) with dedicated monitors (BARCO Coronis Fusion 6MP LED). The readers were allowed to adjust window settings to allow for natural reading conditions. The readers, who were blinded to the nodule distribution, searched the radiographs for lung nodules. Lesions were recorded on a standardized readout sheet by documenting their location. Results were compared to the ground truth, analogous to the AI readout.