Side‐to‐side differences and day‐to‐day variations of transcranial Doppler parameters in normal subjects.

We investigated 35 normal adults to assess variations in cerebral artery blood velocities, hemispheric blood velocity ratios, and pulsatility indices, both with regard to changes between the sides and between days. We found no significant variations between sides or days. Changes from one day to the next exceeding 20% in blood velocity in the middle cerebral artery (VMCA), the anterior cerebral artery (VACA), the distal extracranial internal carotid artery (VICA), and in the hemispheric VMCA/VICA, VACA/VICA, or VACA/VMCA ratios, may be considered significant at the 95% level.

[1]  B. Arnolds,et al.  Transcranial Doppler sonography. Examination technique and normal reference values. , 1986, Ultrasound in medicine & biology.

[2]  R. Aaslid,et al.  Noninvasive transcranial Doppler ultrasound recording of flow velocity in basal cerebral arteries. , 1982, Journal of neurosurgery.

[3]  A. Alavi,et al.  The Effect of Anxiety on Cortical Cerebral Blood Flow and Metabolism , 1987, Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism.

[4]  B. Weir,et al.  Time course of vasospasm in man. , 1978, Journal of neurosurgery.

[5]  H. Riggs,et al.  Variation in form of circle of Willis. The relation of the variations to collateral circulation: anatomic analysis. , 1963, Archives of neurology.

[6]  A. Brubakk,et al.  Measurement of instantaneous blood-flow velocity in the human aorta using pulsed Doppler ultrasound. , 1982, Cardiovascular research.

[7]  R. Aaslid,et al.  Cerebral vasospasm evaluated by transcranial ultrasound correlated with clinical grade and CT-visualized subarachnoid hemorrhage. , 1986, Journal of neurosurgery.

[8]  L. Wechsler,et al.  Transcranial Doppler in cerebrovascular disease. , 1986, Stroke.

[9]  R. Aaslid,et al.  Evaluation of cerebrovascular spasm with transcranial Doppler ultrasound. , 1984, Journal of neurosurgery.

[10]  R. G. Berry,et al.  Anatomical studies of the circle of Willis in normal brain. , 1959, A.M.A. archives of neurology and psychiatry.

[11]  K. Rootwelt,et al.  Measurement of cerebral blood flow with 133Xe inhalation and dynamic single photon emission computer tomography. Normal values. , 1986, Scandinavian journal of clinical and laboratory investigation. Supplementum.

[12]  D. H. King,et al.  Arterial assessment by Doppler-shift ultrasound. , 1974, Proceedings of the Royal Society of Medicine.

[13]  R. Aaslid,et al.  Dependency of Blood Flow Velocity in the Middle Cerebral Artery on End-Tidal Carbon Dioxide Partial Pressure—A Transcranial Ultrasound Doppler Study , 1984, Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism.

[14]  R. Aaslid,et al.  Doppler diagnosis of intracranial artery occlusive disorders. , 1986, Journal of neurology, neurosurgery, and psychiatry.

[15]  J. Gillard,et al.  Transcranial measurement of blood velocities in the basal cerebral arteries using pulsed Doppler ultrasound: a method of assessing the Circle of Willis. , 1986, Ultrasound in medicine & biology.

[16]  A. Harders,et al.  Time course of blood velocity changes related to vasospasm in the circle of Willis measured by transcranial Doppler ultrasound. , 1987, Journal of neurosurgery.

[17]  R. Aaslid,et al.  Assessment of intracranial hemodynamics in carotid artery disease by transcranial Doppler ultrasound. , 1985, Journal of neurosurgery.