Chapter 7. Guidelines in Neuroimaging in Stroke

Question 1

What is the reason of hyperdensity in NCCT

Answer 1

due to increase protein due to clot retraction from globin particle

Question 2

5 Early signs of ischemia in NCCT

Answer 2

1. Hyperdense MCA “dot sign”
2. Obscuration of lentiform nucleus
3. Loss of gray white matter differentiation
4. Insular Ribbon Sign
5. Sulcal Effacement

Question 3

What is the explanation of presence of obscuration of lentiform nucleus in acute ischemia

Answer 3

Failure of ion pump to maintain cellular homeostasis causing influx of water

Question 4

What is the explanation of presence of Hyperdense MCA sign in acute ischemia

Answer 4

Clot retraction

Question 5

What is the least sensitive in early signs in NCCT

Answer 5

Hyperdense MCA sign

Question 6

This is define as average time it takes to transit through a volume of brain

Answer 6

Mean transit time

Question 7

This represent the altered area of the brain risk for infarction

Answer 7

Cerebral blood flow

Question 8

What represents the penumbra

Answer 8

MTT

Question 9

Penumbra is defined as

Answer 9

Increased MTT
Decreased CBF
Normal to mildly elevated CBV

Question 10

Infarcted tissue

Answer 10

Decreased CBF and CBV

Increased MTT

Question 11

CT technique where it is able to identify the core of infarct

Answer 11

CTA source imaging (CTA-SI)

Question 12

This is a 10 point quantitative CT that determine infarct core volume

Answer 12

ASPECTS

Question 13

This is based on restricted diffusion of water molecule as a result of movement of extracellular water into intracellular compartment

Answer 13

Diffusion weighted imaging

Question 14

This is a random movement of water

Answer 14

Brownian Motion

Question 15

The image protocol and creating image of human anatomy is using this method

Answer 15

Pulse Sequence

Question 16

Depicts the area of restricted diffusion as low intensity signal

Answer 16

Apparent Diffusion Coefficient

Question 17

Peak duration where ADC continues to decrease its intensity

Answer 17

3-5 days

Question 18

What are the sequence in MRI important for dating infarcts

Answer 18

DWI
ADC
T2

Question 19

This sequence is sensitive in detecting microbleeds in chronic hypertension

Answer 19

GRE

Question 20

What does SWI provides additional information

Answer 20

Detect hemorrhage with in infarct
Areas of hypoperfusion
Acute thromboembolic occluding artery

Question 21

What sequence helps to establish the age of infarct

Answer 21

T2 and T1

Question 22

Sequence of hemoglobin metabolism in MRI

Answer 22

Hyperacute - OxyHgb
Acute - DeoxyHgb
Early Subacute - MethylHgb
Subacute-Chronic - Extracellular Hgb

Question 23

Sequence of intensity of T1 from Acute - Chronic

Answer 23

Iso
Iso-Hyper
Hyper
Hyper

Question 24

Sequence of intensity of T2 from Acute - Chronic

Answer 24

Hyper
Hypo
Hypo
Hyper

Question 25

Remote bleeds will appear in T2 and T1 imaging

Answer 25

Hypointense

Question 26

How many percent will give early signs of infarct in CT-scan during hyperacute stage

Answer 26

60%