A 51-year-old male patient with a past history of lung tuberculosis presented for routine control. The patient reported no complaints. He smoked 40 packets of cigarettes per year and had suffered from tuberculosis 20 years ago and had been treated. Physical examination and laboratory findings were within normal limits; chest X-ray showed bilateral hyperlucency (Figure 1). Chest CT revealed DAA surrounding the trachea on both sides. Left and right arches were equal in size although the right arch was located 5 mm higher than the left (Figure 2). A three-dimensional CT scan was taken (1) to obtain better anatomic views and (2) to clearly identify its relation to neighboring structures (Figure 3). These images show clearly that the DAA is a balanced type and there is no compression of either trachea or esophagus. Echocardiography was normal. Bronchoscopy was not performed due to lack of respiratory symptoms.