CT Perfusion Of The Brain

Question 1

The comprehensive MDCT management of acute stoke consists of:

Answer 1

1) precontrast head CT
2) CTA of the brain and carotid arteries.
3) CT perfusion (CTP) imaging.

Question 2

Cerebral blood volume (CBV) :

Answer 2

The quantity of blood (in mL) contained within a 100-g volume of brain tissue. Normal range is 4-5 mL/100 g.

Question 3

Cerebral blood flow (CBF) :

Answer 3

The quantity of blood (mL) that moves through -0” g of brain tissue each minute. Normal range in gray matter is 50 - 60 mL/100g/minute.

Question 4

Mean transit time (MTT) :

Answer 4

The average transit time, in seconds, for blood to pass through a given region of brain tissue. MTT varies according to the distance travelled between arterial inflow and venous outflow for a particular area.

Question 5

Central volume principle illustrates the relationship between CBV, CBF & MTT as follows:

Answer 5

CBF = CBV/MTT

Question 6

Primary indication for CTP is

Answer 6

Evaluation of acute stroke.

Question 7

The primary goal of CTP is to identify and differentiate the

Answer 7

Infarct core and penumbra.

Question 8

Brain tissue within the infarction core is:

Answer 8

Beyond repair by thrombolytic therapy.

Question 9

The penumbra is:

Answer 9

The ischemic yet still viable tissue immediately surrounding the infarct core.

Question 10

What percentage of a decrease in blood flow is demonstrated in ischemic tissue?

Answer 10

> 34%

Question 11

The penumbra can be described as the region of ischemic parenchyma where

Answer 11

CBV is still greater than 2.5mL/100g.

Question 12

Brain parenchyma with a CBV less than —— is identified as the infarct core.

Answer 12

2.5mL/100g.

Question 13

CTP imaging of the brain generates quantitative maps of:

Answer 13

CBF, CBV, & MTT. These maps can help distinguish regions of ischemic penumbra from an infarct core.