Artifacts in the ascending aorta on computed tomography: another measure of aortic distensibility?

The appearance of the ascending aorta was studied in 53 patients undergoing computed tomography on a modern system capable of routine 1 second data acquisition times. Motion artifact caused a blurred aortic outline in 48 patients; the extent was objectively and subjectively assessed. The maximum and minimum cross-sectional aortic areas were measured at the margins of the blur. The area of the blur, expressed as a fraction of the minimum aortic cross-sectional area, decreased with age (P < 0.001) and was significantly smaller in the 13 patients with known cardiovascular problems (P < 0.05). These findings were substantiated by the subjective gradings which showed less marked artifacts amongst elderly patients (although this observation did not reach statistical significance). Artifacts were less prominent in 16 patients with evidence of aortic wall calcification, both on subjective grading (P < 0.05) and formal area measurements (P < 0.05). These observations lead us to believe our postulation that this artifact is an indicator of aortic distensibility and thus, indirectly, of cardiovascular status.