Abstract
Difficulties in location of transcranial ultrasound (US) windows and blood flow in
cerebral vessels, and unambiguous detection of microemboli, have limited expansion
of transcranial Doppler US. We developed a new transcranial Doppler modality, power
M-mode Doppler (PMD), for addressing these issues. A 2-MHz digital Doppler (Spencer
Technologies TCD100M) having 33 sample gates placed with 2-mm spacing was configured
to display Doppler signal power, colored red and blue for directionality, in an M-mode
format. The spectrogram from a user-selected depth was displayed simultaneously. This
system was then explored on healthy subjects and patients presenting with varying
cerebrovascular pathology. PMD facilitated window location and alignment of the US
beam to view blood flow from multiple vessels simultaneously, without sound or spectral
clues. Microemboli appeared as characteristic sloping high-power tracks in the PMD
image. Power M-mode Doppler is a new paradigm facilitating vessel location, diagnosis,
monitoring and microembolus detection. (E-mail: [email protected])
Keywords
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Article info
Publication history
Accepted:
October 3,
2001
Received:
July 13,
2001
Identification
Copyright
© 2002 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.
