Motion artifacts of the aorta simulating aortic dissection on spiral CT

Purpose: Motion artifacts of the ascending aorta may impair image quality a nd simulate an intimal flap or a false channel. The purpose of this study i s to evaluate the prevalence, amplitude, and extent of motion artifacts of the aorta in spiral CT and to specify the effects of acquisition and recons truction parameters on these artifacts. Method: One hundred seventy-one thoracic spiral CT examinations were retros pectively analyzed by two reviewers. The analysis sought to determine the p resence, location, amplitude, and extent of artifacts of the ascending aort a. Results: Aortic artifacts were detected on spiral CT in 57% of cases. The m ean amplitude and mean extent were 4 +/- 4 and 6 +/- 7 mm, respectively. Ar tifacts in the ascending aorta were significantly higher with the 360 degre es linear interpolation (LI) algorithm than with the 180 degrees LI algorit hm. Conclusion: The prevalence of motion artifacts on spiral CT is higher in th is study than the reported prevalence in incremental CT. However, this high er prevalence is significantly reduced when the 180 degrees LI algorithm is used.