Figure 1.

Schematic algorithm over the inclusion and exclusion of patients. All patients that underwent a carotid ultrasonographic (US) examination between 2004-01-01 and 2006-03-31 where included in the analysis of US indications. The patients with a carotid stenosis ≥ 50% and the presence or absence of a carotid bruit in their medical records were included in the analysis of carotid bruit statistics.