Document Detail


The depth of microembolic signal direction change corresponds with vessel anatomy.
MedLine Citation:
PMID:  15644632     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
BACKGROUND: Analysis of microembolic signals (MES) suggests a change of flow direction (CFD). The aim of the present study was to relate MES direction in an amplitude plot, based on the radiofrequent (RF) signal, to the vascular anatomy as seen with transcranial color-coded duplex (TCCD). METHODS: In 5 patients undergoing heart valve surgery or aortic arch replacement, preoperatively TCCD of the distal part of the internal carotid artery and the middle and anterior cerebral arteries on the right side was performed to determine potential depths of changes in flow direction. Peroperatively, a transcranial pulsed Doppler (TCD) monitoring probe was fixed over the right temporal bone. A customized RF-based system, connected to the TCD device, captured and stored the MES. Off-line, the color-coded amplitude of the clutter-filtered RF signals was plotted as a function of time (sample interval 0.17 ms) and depth (sample interval 0.05 mm). RESULTS: A total of 313 MES were recorded in 4 patients with 66 MES (21%) showing a CFD. All MES with CFD could be assigned to maximally three different depth values, six out of eight CFD depth values as seen with the RF analysis were within 1 mm from a turn in flow direction as estimated with TCCD. CONCLUSIONS: A CFD of MES occurred at a very limited number of depths and corresponded mostly with the intracranial vascular anatomy, namely a turn of the flow direction in the intracranial vessels as observed with TCCD.
Authors:
W H Mess; J M Willigers; R G A Ackerstaff; Th W O Elenbaas; A P G Hoeks
Publication Detail:
Type:  Clinical Trial; Journal Article     Date:  2005-01-11
Journal Detail:
Title:  Cerebrovascular diseases (Basel, Switzerland)     Volume:  19     ISSN:  1015-9770     ISO Abbreviation:  Cerebrovasc. Dis.     Publication Date:  2005  
Date Detail:
Created Date:  2005-03-08     Completed Date:  2005-04-28     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  9100851     Medline TA:  Cerebrovasc Dis     Country:  Switzerland    
Other Details:
Languages:  eng     Pagination:  186-91     Citation Subset:  IM    
Copyright Information:
Copyright 2005 S. Karger AG, Basel
Affiliation:
Department of Clinical Neurophysiology, University Hospital Maastricht, Maastricht University, AZ Maastricht, The Netherlands. WME@fknf.azm.nl
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MeSH Terms
Descriptor/Qualifier:
Carotid Artery, Internal / ultrasonography
Cerebrovascular Circulation*
Humans
Infarction, Middle Cerebral Artery / ultrasonography*
Middle Cerebral Artery / anatomy & histology*,  physiology,  ultrasonography*
Monitoring, Intraoperative / methods
Ultrasonography, Doppler, Transcranial / methods*

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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