Unit 6

Question 1

What is a spin echo sequence?

Answer 1

90 degree pulw follwed by a 180 degree pulse

Question 2

What is a gradient echo sequence?

Answer 2

<90 degree pulse followed by gradient echo

Question 3

What is an inversion recovery sequence?

Answer 3

180 degree pulse followed by a 90 degree pulse, then a 180 degree pulse

Question 4

What is echo time?

Answer 4

time between excitation and receiving signal

Question 5

What is inversion time?

Answer 5

time between 180 degree pulse an 90 degree pulse in IR sequences

Question 6

What TR values are used in T1 weighted images?

Answer 6

<800msec (short)

Question 7

What TE values are used in T1 weighted images

Answer 7

<25msec (short)

Question 8

What TR values are used in T2 weighted images?

Answer 8

> 2,000msec

Question 9

What TE values are use in T2 weighted images?

Answer 9

> 80msec

Question 10

What TR values are used in PD weighted images?

Answer 10

> 2,000msec

Question 11

What TE values are used in PD weighted images?

Answer 11

<35msec

Question 12

advantages of GRE over SE

Answer 12

shorter scan time

Question 13

Advantages of SE over GRE

Answer 13

180 degree pulse compensates for inhomogeneity, greater signal

Question 14

What type of sequence is T2*?

Answer 14

GRE

Question 15

What is the use of IR imaging?

Answer 15

signal suppression (fat vs fluid)

Question 16

How does gadolinium create contrast?

Answer 16

shortens T1 and T2 relaxation time

Question 17

How does contrast appear on T1 weighted images?

Answer 17

increased intensity

Question 18

How does contrast appear on T2 weighted images?

Answer 18

decreased intensity

Question 19

Why does gadolinium not significantly affect T2 weighted images?

Answer 19

there isn’t enough gadolinium concentration

Question 20

What makes gadolinium contrast safe to administer?

Answer 20

the gadolinium is bound in an inert substance.