TCD

How many people do not have an ACA

25%

What should you do before changing to transorbital window

Turn down power 10%

What frequency transducer is used

2 MHz

Transorbital evaluates

ophthalmic artery and carotid siphon

Transtemporal evaluates

ACA, MCA, TICA, PCA

Transoccipital evaluates

Basilar and vertebral arteries

Assumed Doppler angle is

0

MCA runs parallel to what bone

Temporal

MCA sample volume depth

30-60

MCA flow direction

Antegrade

TICA sample volume

55-65

TICA flow direction

Bidirectional

ACA sample volume depth

60-80

Flow direction of ACA

Retrograde

PCA sample volume depth

60-70

PCA direction flow

Antegrade

Siphon sample volume depth

60-80

Ophthalmic sample volume depth

40-60

Ophthalmic flow direction

Antegrade

Vertebral artery sample volume depth

60-90

Vertebral artery flow direction

Retrograde

Basilar artery sample volume depth

80-120

Basilar artery flow direction

Retrograde

MCA mean velocity

55 +- 12

TICA mean velocity

39+- 9

ACA mean velocity

50 +- 11

PCA mean velocity

40 +- 10

Siphon mean velocity

47 +- 14

Ophthalmic artery mean velocity

21 +- 5

Vertebral artery mean velocity

38 +- 10

Basilar artery mean velocity

41 +- 10

Increased velocities seen in

Localized stenosis, vasospasms, AVM

Decreased pulsatility seen in

Significant stenosis, occlusion

A mean MCA velocity of less than 120 indicates

Normal to mild vasospasm

A mean MCA velocity of 120-200 indicates

Moderate spasm

A mean MCA velocity of greater than 200 indicates

Severe spasm

Normal PI for MCA, ACA, and PCA

0.5-1.1

ACoA is prone to what aneurysm

Berry