Cavitation of missile tracks in the lung.

Abstract

Recently we have noticed an unusual phenomenon in several cases of gunshot wound to the chest. On roentgenologic examination the missile track appeared to have a clear center, especially when viewed en face; the clear center was also usually seen in the profile view. In order to determine the incidence and roentgenographic patterns established by this phenomenon, all cases of gunshot wound to the chest in 1965 were reviewed. Out of 62 cases in this series, 4 demonstrated a missile track with a clear center. Case Reports Case I: A 15-year-old male was shot with a .22 caliber pistol from a distance of less than 6 feet. The entrance wound was in the left third intercostal space adjacent to the sternum, and the exit wound was just below the tip of the left scapula. A thoracocentesis just after hospitalization produced 1,000 cc of blood. The post-thoracocentesis chest film revealed a vague density that was interpreted as contusion in the left midlung field obscuring the bullet track. On the fifth day another thoracocentesis produced 150 cc of “frank dark red blood.” A chest film at this time revealed partial resolution of the left lower lung field infiltrates and the first appearance of a denser opacification along the bullet path that was thought to be a hematoma. A clear center was noted in this bullet path opacification. There was continued resolution of the left lower lung infiltrate on the seventh day. The inside diameter of the tube of hematoma had decreased slightly. The lateral roentgenogram showed partial left lower lung opacification without decrease in volume. The bullet path was seen in profile, appearing as two dense linear lines separated by a radiolucent center. Tiny specks of lead could be seen along the bullet path on the original roentgenogram (Fig. 1). By the thirty-fourth day the bullet track had completely collapsed, leaving only a streak of fibrosis. Case II: A 53-year-old male shot himself with a .22 caliber weapon in the right first intercostal space lateral to the midclavicular line. A recumbent anteroposterior chest film revealed a ring of contusion and/or hematoma with a clear center along the bullet path. There was a fracture of the right ninth rib posteriorly (Fig. 2). On the second day recumbent anteroposterior chest films revealed partial resolution of the infiltrate about the bullet path. By the tenth day there had been almost complete resolution of the condensed lung surrounding the bullet path, leaving only a thin, densely opacified wall. There had been no collapse of the hollow center. An infiltrate was noted in the right upper lung surrounding the site of a thoracotomy tube which simulated a missile track. Case III: A 35-year-old female was shot with a .22 caliber weapon in the left upper breast just lateral to the midclavicular line. An infiltrate was noted along the bullet path. On the second day an anteroposterior recumbent film of the chest showed cavitation in the bullet track.