Chapter 19: Transcranial Doppler

Question 1

TCD is used for

Answer 1

detecting intracranial stenosis, occlusions
eval onset of vasoconstriction from aubarachnoid hemorrage
eval intracranial AV malformations
asses patients with suspected brain death

Question 2

Limitations of TCD

Answer 2

resent eye surgery limiting transorbital approach
penetration of temporal bone
inaccurate vessel identification

Question 3

patient positioning for TCD

Answer 3

supine

avoid speaking during exam

Question 4

what to do for TCD

Answer 4

2MHz pulsed doppler with spectrum analysis
zero angle of insonation
time average maximum velocity TAMV or mean velocity is used

Question 5

three acoustic windows for TCD

Answer 5

transtemporal
transorbital
transforaminal/suboccipital

Question 6

accurate vessel identification requires

Answer 6

depth of sample volume
velocity of blood flow
direction of flow
relationship of flow patterns to one another

Question 7

unilateral transtemporal approach for

Answer 7

MCA
ACA
PCA
terminal ICA

Question 8

ipsilateral transorbital approach for

Answer 8

ophthalmic artery and carotid siphon

Question 9

transforaminal/suboccipital approach used for

Answer 9

intracranial vertebral and basilar arteries

Question 10

flow direction is usually from

Answer 10

anterior to posterior

Question 11

inappropriate doppler angle usually

Answer 11

negates ability to insonate posterior communicating arteries

Question 12

MCA

Answer 12

approach: transtemporal
depth: 30-60mm
direction: antegrade
Velocity: 55 +/- 12cm/sec
angle: anterior/superior

Question 13

Terminal ICA

Answer 13

approach: transtemporal
depth: 55-65mm
direction: bidirectional
Velocity: 55 +/- 12cm/sec
angle: anterior/superior

Question 14

ACA

Answer 14

approach: transtemporal
depth: 60-80mm
direction: retrograde
Velocity: 50 +/- 11 cm/sec
angle: anterior/superior

Question 15

PCA

Answer 15

approach: transtemporal
depth: 60-70mm
direction: antegrade
Velocity: 39 +/- 10cm/sec
angle: posterior

Question 16

Ophthalmic artery

Answer 16

approach: transorbital
depth: 40-60mm
direction: antegrade
Velocity: 21 +/- 5cm/sec
angle: medial

Question 17

ICA at siphon

Answer 17

approach: transorbital
depth: 60-80mm
direction: supraclinoid: retrograde
genu: bidirectional
parasellar: antegrade
Velocity: 47 +/- 14cm/sec
angle: varies

Question 18

Vertebral Artery

Answer 18

approach: transforaminal
depth: 60-90mm
direction: retrograde
Velocity: 58 +/- 10cm/sec
angle: right/left of midline

Question 19

Basilar artery

Answer 19

approach: transforaminal
depth: 80-120mm
direction: retrograde
Velocity: 41 +/- 10cm/sec
angle: midline

Question 20

crossover of ACA

Answer 20

antegrade flow in ACA from cross over collateralization

Question 21

extrernal to internal collateralization

Answer 21

retrograde flow in ophthalmic artery

Question 22

Posterior to anterior collateral pathway

Answer 22

increased flow in posterior cerebral artery

reversed direction of flow in the pcom artery

Question 23

occlusion is most accurately identified in

Answer 23

ICA or MCA

Question 24

vasospasm is most accurately identified in

Answer 24

MCA

Question 25

vasospam

Answer 25

> 120cm/sec

Question 26

severe vasospam

Answer 26

> 200cm/sec

Question 27

AV malformation findings

Answer 27

increased systolic and diastolic flow velocities
low pulsatility indices
reduced flow in adjacent arteries