title: [Reference values for measures of blood flow velocities and impedance indexes in healthy individuals through conventional transcranial Doppler].
abstract: OBJECTIVE
  To establish reference values for measures of blood flow velocities and impedance indexes in healthy individuals through conventional transcranial Doppler (TCD) and to observe their variations in relation to the age and sex.
  
  
  METHODS
  88 asymptomatic volunteers were examined without antecedents of cardiac, peripheral or cerebrovascular diseases. The TCD were accomplished by the same examiner. The middle, anterior and posterior cerebral arteries were studied through the temporal acoustic window and the vertebral and basilar arteries through the suboccipital acoustic window. The values of mean velocity (MV), peak-systolic velocity (PSV), final diastolic velocity (FDV), resistance index (RI) and pulsatility index (PI) of each examined arterial segment were filed.
  
  
  RESULTS
  The reference limits found by us were similar to the described by other authors for all of the studied parameters. There was tendency of the flow velocities decrease and of the impedance indexes increase with moving forward of the age. The values of velocities in the women were superior to the found in men.
  
  
  CONCLUSIONS
  TCD was shown useful in the evaluation of hemodynamic cerebral for our population. Our results are similar to the other studies, so much in the reference values as in relationship with the age and the sex.
authors.affiliation: Departamento de Diagnóstico por Imagem, Universidade Federal de São Paulo, SP, Brazil. maufbarbosa@hotmail.com
authors.forename: Maurício Fregonesi
authors.initials: MF
authors.lastname: Barbosa
authors.forename: Nitamar
authors.initials: N
authors.lastname: Abdala
authors.forename: Henrique
authors.initials: H
authors.lastname: Carrete
authors.forename: Roberto Gomes
authors.initials: RG
authors.lastname: Nogueira
authors.forename: Darcio Roberto
authors.initials: DR
authors.lastname: Nalli
authors.forename: José Roberto Falco
authors.initials: JR
authors.lastname: Fonseca
authors.forename: Jacob
authors.initials: J
authors.lastname: Szejnfeld
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001783:Blood Flow Velocity / Q000502:physiology*; D001921:Brain / Q000098:blood supply*; D002536:Cerebral Arteries / Q000000981:diagnostic imaging* / Q000502:physiology; D002560:Cerebrovascular Circulation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D017585:Ultrasonography, Doppler, Transcranial