[Dissection-like artifact on one-second scanning time CT]

Dissection-like artifact (DLA) is noted only on one-second scanning time CT image. It is usually observed in the ascending aorta, and less commonly in the superior vena cava and right pulmonary artery. We evaluated 136 cases of thoracic CT (including 20 cases of heart failure), and examined how often and where the artifact is noted and why it is produced. DLA was noted in the ascending aorta in 99 cases. Among the 99 cases, the same artifacts were also shown in the superior vena cava in 26 cases, and in the right pulmonary artery in 10 cases. DLA was never observed in other great vessels, such as the descending aorta and inferior vena cava. This artifact was not demonstrated in patients with heart failure. We presume that DLA is produced by pulsation of the ascending aorta and pulmonary artery. If the artifact is observed, the patient does not have severe cardiac impairment.