title: Nonstenotic internal carotid arteries: effects of age and blood pressure at the time of scanning on Doppler US velocity measurements.
abstract: OBJECTIVE
  To assess the effects of age and blood pressure at the time of scanning on internal carotid artery velocities and cross-sectional diameter at Doppler ultrasonography (US).
  
  
  METHODS
  During 12 months, 1,020 consecutive patients underwent internal carotid artery Doppler US. No or minimal arterial disease was found in 142 patients (67 women, 75 men). Blood pressure was recorded prior to examination. The angle-corrected internal carotid artery peak systolic and end-diastolic velocities were obtained. The effects of systolic blood pressure, diastolic blood pressure, pulse pressure, age, chronic hypertension, and medications for hypertension on velocities were evaluated by using linear regression analysis.
  
  
  RESULTS
  Peak systolic velocity was influenced by age (P =.008), systolic blood pressure (P =.009), diastolic blood pressure (P =.003), and pulse pressure (P =.017) but not history of hypertension (P =.53) or antihypertensive medication use (P =.77). Increasing age decreased peak systolic velocity by 0.34 cm/sec/y. End-diastolic velocity was influenced by age (P <.001) but not by systolic, diastolic, or pulse pressure (all P values were >.13).
  
  
  CONCLUSIONS
  Internal carotid artery peak systolic velocities decrease with advancing age and increase with increasing pulse pressure. The effects of blood pressure at the time of scanning are small, but isolated systolic hypertension could cause increases in spurious velocity.
authors: Department of Radiology, Duke University Medical Center, Box 3808, Durham, NC 27710, USA.
authors: E B
authors: EB
authors: Spencer
authors: D H
authors: DH
authors: Sheafor
authors: B S
authors: BS
authors: Hertzberg
authors: J D
authors: JD
authors: Bowie
authors: R C
authors: RC
authors: Nelson
authors: B A
authors: BA
authors: Carroll
authors: M A
authors: MA
authors: Kliewer
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D001783:Blood Flow Velocity; D001794:Blood Pressure; D001795:Blood Pressure Determination; D002340:Carotid Artery Diseases / Q000000981:diagnostic imaging / Q000503:physiopathology; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging* / Q000502:physiology*; D003971:Diastole / Q000502:physiology; D005260:Female; D006801:Humans; D017078:Laser-Doppler Flowmetry; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012016:Reference Values; D012044:Regression Analysis; D012680:Sensitivity and Specificity; D013599:Systole / Q000502:physiology; D018608:Ultrasonography, Doppler / Q000379:methods*