title: Duplex US of the external carotid artery.
abstract: The ratio between the systolic peak velocities of the internal and common carotid arteries (vpICA/vpCCA), vpICA and grey-scale imaging measurement are generally used to evaluate internal carotid stenosis against known flow criteria in order to differentiate non-significant from significant stenosis. The same criteria are also used for evaluating the external carotid artery (ECA). Our data on 707 normal or stenotic ECA nevertheless showed that the systolic peak velocity of the normal ECA (vpECA) and its ratio to the systolic velocity of the CCA (vpECA/vpCCA) are higher than vpICA and vpICA/vpCCA. vpECA/vpCCA is about 2 in > 0-49% ECA stenosis. Only in severe stenosis are the peak velocities almost comparable. The ratio between the peak end diastolic velocities (edvECA/edvCCA) and edvECA proved to be unreliable, as did grey-scale imaging measurement of the external carotid stenosis. In addition, ipsi-lateral internal carotid stenosis greatly affects the non-stenotic external carotid flow values, and probably has the same effect on the flow values of a stenotic external artery. Thus, external carotid flow values must be considered carefully.
authors.affiliation: Department of Radiology, University Central Hospital, Oulu, Finland.
authors.forename: M J
authors.initials: MJ
authors.lastname: Päivänsalo
authors.forename: T M
authors.initials: TM
authors.lastname: Siniluoto
authors.forename: T A
authors.initials: TA
authors.lastname: Tikkakoski
authors.forename: V
authors.initials: V
authors.lastname: Myllylä
authors.forename: I J
authors.initials: IJ
authors.lastname: Suramo
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001783:Blood Flow Velocity; D017536:Carotid Artery, Common / Q000000981:diagnostic imaging; D002342:Carotid Artery, External / Q000000981:diagnostic imaging* / Q000502:physiology; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging; D016893:Carotid Stenosis / Q000000981:diagnostic imaging / Q000503:physiopathology; D003287:Contrast Media; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D011859:Radiography; D012016:Reference Values; D012044:Regression Analysis; D018616:Ultrasonography, Doppler, Duplex / Q000295:instrumentation / Q000379:methods / Q000706:statistics & numerical data
chemical_list: D003287:Contrast Media