title: Extracranial carotid Doppler ultrasound evaluation of cerebral blood flow volume in COPD patients.
abstract: OBJECTIVE
  Doppler ultrasound of extracranial internal carotid artery (ICA) and vertebral artery (VA) were performed and total cerebral blood flow volume (tCBFV) was evaluated in chronic obstructive pulmonary disease (COPD) patients. CBFV changes due to blood gas changes were also evaluated.
  
  
  METHODS
  Bilateral ICA and VA have been examined with 7.5 MHz linear array transducer in COPD patients. Angle-corrected time averaged flow velocity and cross-sectional areas of vessels have been measured. Flow volumes and tCBFV have been calculated. Flow velocities and waveform parameters have been measured.
  
  
  RESULTS
  tCBFV, anterior-posterior CBFVs, left-right ICA flow volumes, bilateral ICA and VA cross-sectional areas and left ICA peak-systolic velocity were significantly higher in COPD patients than control group. Among COPD patients tCBFVs were highest in hypoxemic-hypercapnic ones, and lowest in normocapnic ones. Bilateral VA flow volumes, bilateral ICA (except left ICA V(ps)) and VA flow velocities and waveform parameters were not different in COPD patients compared with control group. When compared among the subgroups of COPD patients, there were no significant differences for all parameters.
  
  
  CONCLUSIONS
  tCBFVs were found to be significantly higher in COPD patients. This increment which is probably due to balancing the oxygen deficit is low with hypoxemia and high with hypercapnia and hypoxemia. Particularly, bilateral ICA and VA cross-sectional area changes and increased left ICA V(ps) were considered as the main reason for increased tCBFV in COPD patients.
authors.affiliation: Department of Radiology, Faculty of Medicine, Afyon Kocatepe University, 03100, Afyon, Turkey. rtalbayrak@yahoo.com
authors.forename: Ramazan
authors.initials: R
authors.lastname: Albayrak
authors.forename: Fatma
authors.initials: F
authors.lastname: Fidan
authors.forename: Mehmet
authors.initials: M
authors.lastname: Unlu
authors.forename: Murat
authors.initials: M
authors.lastname: Sezer
authors.forename: Bumin
authors.initials: B
authors.lastname: Degirmenci
authors.forename: Murat
authors.initials: M
authors.lastname: Acar
authors.forename: Alpay
authors.initials: A
authors.lastname: Haktanir
authors.forename: Mehmet
authors.initials: M
authors.lastname: Yaman
mesh_terms: D000368:Aged; D001783:Blood Flow Velocity / Q000502:physiology; D001810:Blood Volume / Q000502:physiology; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging / Q000473:pathology / Q000502:physiology; D016022:Case-Control Studies; D002560:Cerebrovascular Circulation / Q000502:physiology*; D006801:Humans; D029424:Pulmonary Disease, Chronic Obstructive / Q000473:pathology / Q000503:physiopathology*; D017585:Ultrasonography, Doppler, Transcranial / Q000379:methods; D014711:Vertebral Artery / Q000000981:diagnostic imaging / Q000473:pathology / Q000502:physiology