A case of PDA in a 56 -year-old female patient (group 2) missed on both the initial CT report and by the two blind readers. On axial post-contrast images with 3 mm slice-thickness at the level of tracheal carina, a small linear enhancing structure (arrow) connecting the left main pulmonary artery (P) and aortic isthmus (A) is subtly noted, but was missed on the initial CT reading.