Velocities

Question 1

How are the contralateral ACA velocities affected in the presence of crossover/right to left?

Answer 1

> 150% increase

Question 2

How does the ACA flow change in cross over?

Answer 2

Ipsilateral ACA will become antegrade (reversed).

Question 3

How are MCA velocities affected during compression in crossover?

Answer 3

MCA will decrease with contralateral compression

Question 4

How does the ophthalmic flow change in external to internal?

Answer 4

Ipsilateral will become retrograde (reversed)

Question 5

How does ipsilateral compression of the ECA affect the ophthalmic in external to internal?

Answer 5

Reduction, obliteration or reversal of flow

Question 6

How is the flow in the ipsilateral PCA changed in posterior to anterior?

Answer 6

PCA will exceed MCA by 125%

Question 7

How does compression of the CCA affect the velocities in posterior to anterior?

Answer 7

Increased velocities

Question 8

If both vertebrals are diseased, how is the basilar affected?

Answer 8

Reduced velocity or to and fro.

Question 9

How high can velocities be with an AV malformation?

Answer 9

280

Question 10

What should the MCA be during clamping of the carotid artery during surgery?

Answer 10

> 10 cm/sec is adequate

Question 11

Where does Subarachnoid Hemorrhage occur?

Answer 11

Between arachnoid and pia layers of cerebrum

Question 12

What is vasospasm?

Answer 12

Spasm of cerebral arteries (complication of SAH) that can reduce perfusion

Question 13

What MCA vel during a vasospasm is a reaction to documented hemhorrage?

Answer 13

> 120

Question 14

What MCA vel increase during a vasospasm indicates poor prognosis?

Answer 14

Increase >20 per day

Question 15

What MCA vel during a vasospasm is a critical reduction in blood flow?

Answer 15

> 200

Question 16

How does systolic flow change with brain death?

Answer 16

Decreases to no flow

Question 17

If there is no change to the peripheral vascular beds with CO2 (functional reserve testing/vasomotor reactivity test) what does this mean?

Answer 17

They are already max dilated (exhausting vasomotor reserve)

Question 18

What is sickle cell anemia? (SSA)

Answer 18

Defect of hemoglobin synthesis (africans/south europeans/ asian) sickle shaped RBC’s clump together

Question 19

How often do children with SSA have strokes?

Answer 19

2-20%

Question 20

Criteria for emboli detection? (3)

Answer 20

• <300msec
• Unidirectional
• Snap or chirp on audible

Question 21

What angulation interrogates MCA, Cav ICA, ACA and ACCA in the trans temp window?

Answer 21

Anterior 6 degrees

Question 22

What angulation interrogates PCA, basilar, and PCCA in the trans temp window?

Answer 22

Posterior 5 degrees

Question 23

Transtemporal depth, direction, velocity MCA?

Answer 23

3-6 cm
Towards
55 cm/sec

Question 24

Transtemporal depth, direction, velocity MCA/ACA bifur?

Answer 24

5.5 - 6.5
Bi-directional
50 cm/sec

Question 25

Transtemporal depth, direction, velocity ACA

Answer 25

6-8 Away 50 cm/sec

Question 26

Transtemporal depth, direction, velocity ACCA?

Answer 26

7 cm Direction depends on collateralization Velocity ?

Question 27

Transtemporal depth, direction, velocity PCA 1?

Answer 27

6-7 Towards 40

Question 28

Transtemporal depth, direction, velocity PCA 2?

Answer 28

6.5-7 Away 40

Question 29

Transtemporal depth, direction, velocity ICA?

Answer 29

5.5-6.5 Towards 39 cm/sec

Question 30

Transorbital depth, direction, velocity OA?

Answer 30

4 - 6 cm Towards 21 cm/sec

Question 31

Transorbital depth, direction, velocity supraclinoid?

Answer 31

5.5-8 Away 41 cm/sec

Question 32

Transorbital depth, direction, velocity genu?

Answer 32

5.5-8 Bi-directional Varies

Question 33

Transorbital depth, direction, velocity parastellar?

Answer 33

5.5-8 Towards 47

Question 34

Suboccipital depth, direction, velocity vertebral?

Answer 34

6 - 9 cm Away 38

Question 35

Suboccipital depth, direction, velocity basilar?

Answer 35

8 - 12 Away 41

Question 36

Submandibular depth, direction, velocity extradural distal ICA and siphon?

Answer 36

8 cm Away 30 cm/sec