Background and Purpose To noninvasively estimate cerebral blood flow volume, a prospective study of color duplex sonography of the common, external, and internal carotid arteries and vertebral arteries of healthy adults was done. Cerebral blood flow was calculated with the sum of flow volumes in the internal carotid and vertebral arteries of both sides.Methods Using a 7.0-MHz linear transducer of a computed sonography system, cervical arteries of 48 volunteers (23 women, 25 men; mean age, 35 ±12 years) were examined. We measured angle-corrected time-averaged velocities and the diameter of the vessels and calculated the flow volumes of all arteries. In addition, peak systolic, maximum end-diastolic, and time-averaged maximum velocities and the resistance, pulsatility, and spectral broadening indexes were determined. Furthermore, we analyzed the side-to-side difference, age dependence, and long-term reproducibility of these parameters.

Background and Purpose-Global cerebral blood flow (CBF) is an important yet largely unknown quantity in the treatment of neurological intensive care patients. Color duplex sonography of the extracranial cerebral arteries can be used to measure global CBF volume directly at the bedside. To establish reference data on global CBF volume and to test the influence of sex and age on this parameter, a prospective study was performed in a group of 78 healthy adults aged 20 to 85 years (39 women, 39 men; mean age, 52Ϯ19 years in either sex). Methods-The common, external, and internal carotid arteries and the vertebral arteries were examined with the use of a 7.0-MHz transducer of a computed sonography system. Angle-corrected time-averaged flow velocity and the diameter of the vessel were measured. Intravascular flow volumes were calculated as the product of angle-corrected time-averaged flow velocity and the cross-sectional area of the circular vessel. CBF volume was determined as the sum of flow volumes in the internal carotid and vertebral arteries of both sides. Results-From 20 to 85 years of age, CBF volume decreased significantly (PՅ0.0001), on average by Ϸ3 mL/min per year. There were no sex-linked differences in CBF volume. The mean relative contributions of the internal carotid artery and the vertebral arteries to global CBF volume remained constant with age (76% versus 24%). The reference data on CBF volume established for the groups aged 20 to 39 years, 40 to 59 years, and 60 to 85 years were 727Ϯ102, 656Ϯ121, and 603Ϯ106 mL/min, respectively. Conclusions-The data presented here provide additional information on the natural development of global cerebral perfusion in "benign aging." CBF volume reference data for different age groups were also established. These data provide a basis for the clinical application of CBF volume measurements at the bedside, especially in the monitoring of CBF volume in neurological intensive care patients. Key Words: aging Ⅲ cerebral blood flow Ⅲ ultrasonography, Doppler, duplex G lobal cerebral blood flow (CBF) is an important yet largely unknown quantity in the treatment of neurological intensive care patients suffering, for example, from cerebrovascular disorders and/or intracranial hypertension. Until now, the quantitative measurement of global CBF has only been possible by exposing patients to invasive or to radionuclide techniques. 1-3 These methods are not suitable for either bedside evaluations or follow-up measurements of CBF.Reports on flow volume measurements in extracranial cerebral arteries using Doppler and duplex methods 4 -7 were followed by the first systematic description of global CBF volume estimation in a group of young and middle-aged healthy adults by Schöning et al. 8 The same authors found the intradiane and interdiane and intraobserver and interobserver reproducibility of global CBF volume measurement to be high, 9 comparable in fact to the intradiane reproducibility of CBF with the use of H 2 15 O positron emission tomography. 10 Most intensive care and st...

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