Transcranial Doppler Flashcards
1
Q
Why do TCD?
A
- assessment of pt w/suspicion of brain death (cerebral circulatory arrest)
- collateral circulation patterns
- documentation of subclavian steal*
- evaluation of the vertbrobasilar system*
2
Q
Limitations with TCD
A
- recent eye surgery
- hyperostosis of the temporal bone
- non- imaging, inaccurate due to lack of anatomic landmarks
- absent windows
- anatomic anomalies
- pt movement
3
Q
doubling of the mean is only ___% diameter reduction
A
30
4
Q
MCA
A
- start at 50 depth
- antegrade flow, 60 plus or minus 12 cm/sec
- follow to a depth of 35-40mm (up to 65)
5
Q
at what depth would you see the ‘butterfly’?
A
55-65mm
6
Q
ACA
A
- retrograde flow, 60-75mm
- mean velocity 50 plus or minus 12
- following the ACA to 80mm bidirectional flow noted
7
Q
PCA
A
- antegrade flow
- depth 60-70; 39 plus or minus 10
- flow can be antegrade or retrograde depending on what segment you are on
- closing eyes will decrease flow
8
Q
VA
A
- suboccipital
- depth 60-85mm; retrograde
- 38 plus or minus 10
9
Q
BA
A
- suboccipital
- retrograde, 85-120 depth
- 41 plus or minus 10
10
Q
OA
A
- decrease power 10-20%
- transorbital approach
- 21 plus or minus 5
- first branch of ICA
11
Q
Carotid Siphon
A
- transorbital
- antegrade/retrograde flow 60-80mm
- 47 plus or minus 14
- plused doppler is important because of ability to control power (decreased 10-20%)
12
Q
Submandibular Window
A
- ICA is retrograde
- depth 50mm, 24-28cm
