Fig. 4.

A case of a 50-year-old female patient with a pulmonary nodule. The nodule is located in the left paramediastinal area (danger zone) on the chest radiograph (a). Chest computed tomography revealed a 2.5-cm irregular shape nodule in her left upper lobe (b). The deep learning-based nodule detection (DLD) system detected this nodule and suggested an abnormality probability of 28% (c). All thoracic radiologists (2/2) detected this nodule without the DLD system. However, among other observers, only one radiology resident detected this nodule (1/6) without the DLD system. Using the DLD system, all the observers were able to detect this nodule