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Transcranial Doppler-derived indices of cerebrovascular haemodynamics are independent of depth and angle of insonation.
- Source :
-
Journal of clinical neuroscience : official journal of the Neurosurgical Society of Australasia [J Clin Neurosci] 2020 Dec; Vol. 82 (Pt A), pp. 115-121. Date of Electronic Publication: 2020 Nov 06. - Publication Year :
- 2020
-
Abstract
- Continuous measurement of cerebral blood flow velocity (CBFV) of the middle cerebral artery (MCA) using transcranial Doppler (TCD) and arterial blood pressure (ABP) monitoring enables assessment of cerebrovascular haemodynamics. Further indices describing cerebrovascular function can be calculated from ABP and CBFV, such as the mean index (Mxa) of cerebrovascular autoregulation, the 'time constant of the cerebral arterial bed' (tau), the 'critical closing pressure' (CrCP) and a 'non-invasive estimator of ICP' (nICP). However, TCD is operator-dependent and changes in angle and depth of MCA insonation result in different readings of CBFV. The effect of differing CBFV readings on the calculated secondary indices remains unknown. The aim of this study was to investigate variation in angle and depth of MCA insonation on these secondary indices. In eight patients continuous ABP and ipsilateral CBFV monitoring was performed using two different TCD probes, resulting in four simultaneous CBFV readings at different angles and depths per patient. From all individual recordings, the K-means clustering algorithm was applied to the four simultaneous longitudinal measurements. The average ratios of the between-clusters, sum-of-squares and total sum-of-squares were significantly higher for CBFV than for the indices Mxa, tau and CrCP (p < 0.001, p = 0.007 and p = 0.016) but not for nICP (p = 0.175). The results indicate that Mxa, tau and CrCP seemed to be not affected by depth and angle of TCD insonation, whereas nICP was.<br />Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.<br /> (Copyright © 2020 Elsevier Ltd. All rights reserved.)
- Subjects :
- Adult
Aged
Aged, 80 and over
Blood Flow Velocity physiology
Female
Homeostasis physiology
Humans
Male
Middle Aged
Middle Cerebral Artery diagnostic imaging
Middle Cerebral Artery physiology
Algorithms
Cerebrovascular Circulation physiology
Hemodynamics physiology
Image Interpretation, Computer-Assisted methods
Ultrasonography, Doppler, Transcranial methods
Subjects
Details
- Language :
- English
- ISSN :
- 1532-2653
- Volume :
- 82
- Issue :
- Pt A
- Database :
- MEDLINE
- Journal :
- Journal of clinical neuroscience : official journal of the Neurosurgical Society of Australasia
- Publication Type :
- Academic Journal
- Accession number :
- 33317718
- Full Text :
- https://doi.org/10.1016/j.jocn.2020.10.037