Fig. 1

Computed tomography (CT) findings. A Contrast-enhanced CT showing the large atelectasis (asterisk) adjacent to a thoracic aortic aneurysm treated with a stent graft. The arrows and arrowheads indicate the hypertrophied left pulmonary ligament artery (PLA) and abnormal proliferative vessels in the atelectasis, respectively. B Slab-maximum intensity projection image in the oblique coronal view. Abnormal proliferation of small vessels is observed at the peripheral side of the left PLA. The dashed arrow indicates a pseudoaneurysm. C Volume-rendering image. The continuity from the right subscapular artery to the left PLA via the tortuous complex collateral pathway is clearly visible (arrowheads)