[Intercostal lung hernia diagnosed by computed tomography images under the semilateral position].

A 62-year-old man developed a swelling of the left anterior chest after surgery for a thoracic aortic aneurysm. Chest computed tomography (CT) images in the left semilateral position, which were obtained when his intrathoracic pressure was elevated through the Valsalva maneuver, showed a herniated lung with a fragile site of the surgical wound in the chest wall as a hernial orfice, as well as a hernial sac in the posterior of the greater pectoral muscle. A diagnosis of traumatic hernia occurring after thoracotomy was made, for which radical surgery involving direct closure was performed.