title: Extreme variability of cerebrovascular US results and some solutions.
authors.forename: J J
authors.initials: JJ
authors.lastname: Crittenden
mesh_terms: D002560:Cerebrovascular Circulation; D006801:Humans; D011785:Quality Assurance, Health Care; D015203:Reproducibility of Results; D018608:Ultrasonography, Doppler / Q000592:standards