Special procedures

Question 1

normal blood flow (demonstarted by a parabolic blood flow profile) is known as

Answer 1

laminar flow

Question 2

blood flow at the area of a stenosis is known as

Answer 2

accelerated flow

Question 3

swirling blood flow that occurs just past the area of stenosis is known as

Answer 3

vortex flow

Question 4

normal blood flow is known as

Answer 4

laminar

Question 5

a major advantage of MRA over conventional angiography is taht

Answer 5

multiple views can be produced from a single acquisition

Question 6

the MRA sequence that is least sensitive to slow flow is

Answer 6

3D TOF

Question 7

the MRA sequence that is most sensitive to smaller vessels is

Answer 7

3D TOF

Question 8

the MRA sequence that is sensitive to flow direction is

Answer 8

3D phase contrast MCA (PC MRA)

Question 9

the MRA sequence that can be made sensitive to any flow velocity is

Answer 9

3D PC MRA

Question 10

the signaly intensity of TOF MRA sequences is related to

Answer 10

flow related enhancement

Question 11

the signal intensity of PC MRA sequences is related to

Answer 11

velocity induced phase shift

Question 12

the signal intensity on diffusion sequences is related to

Answer 12

amount of diffusion

Question 13

the followoing are important in MRA sequences to minimize the loss of signal due to dephasing within a voxel

Answer 13

small voxels

short TE

Question 14

blood flow velocities are greatest

Answer 14

at the center of a vessel

Question 15

single order gradient moment nulling does not compensate for

Answer 15

accelerated flow

reverse flow

Question 16

in a spin echo sequence flowoing blood is noirmally seen as a signal void because the

Answer 16

TE is too long to image flow

90 pulse and 180 pulse are both slice selective

Question 17

in a vessel with a plaque producing a high degree of stenosis the velocity of the blood flow in the center point of stenosis is

Answer 17

increased

Question 18

in TOF sequences the tissue is HYPOintense relative to flowoing blood because of the

Answer 18

saturatoin effects

Question 19

in TOF sequence, flowoing blood is HYPERintense relative to stationary tissue because of the

Answer 19

flow related enhancement

Question 20

phase contrast technioques produce images in which the signal intensity within the vessel is dependent on the

Answer 20

velocity of flowoing blood

Question 21

in a phase contrast technique it is possible to use the data to determine the

Answer 21

directoin of blood flow

Question 22

a major advantage of 3D TOF techniques over 2D TOF is the ability to

Answer 22

visualize smaller vessels

Question 23

a major advantage of 2D TOF over 3D TOF is the ability to

Answer 23

image a larger area without saturation of the flowoing blood

Question 24

cardiac cine acquisitions typically utilize

Answer 24

a gradient echo pulse sequence

Question 25

each from of cardiac cine sequence displays the heart

Answer 25

in different phases of the cardiac cycle

Question 26

cine studies are often performed on various joints. the main purpose of such a study is to

Answer 26

visualize motion and function

Question 27

which of the following would result in an image with the treatest amount of diffusion weighting

Answer 27

b-value 1100

Question 28

the main purpose of producing/calculating an ADC map is to

Answer 28

eliminate the T2 shine through

Question 29

changing the b value alters the

Answer 29

amplitude, timing, and or duration of the diffusion gradients

Question 30

when performing a dynamic perfusion exam of the brain utilizing a gadolinium base MR contrast agent, the result of the T2\* shortening is

Answer 30

reduced MR signal

Question 31

the basic MR principle with regard to MR spectroscopy is

Answer 31

chemical shift

Question 32

have acquired a 3D TOF when producing an MRA projection image set upsing MIP technique, which of the following can appear bright and therefore the same as flow within a vessel

Answer 32

tissues or substances with extremely short T1 relaxatoin time

Question 33

the intrinsic contrast mechanism with regard to fMRI is

Answer 33

the BOLD effect

Question 34

all of the techniques can be utilized to optimally time the start of a contrast enhanced MRA

Answer 34

automated bolus detectoin test bolus real time.flouro triggering

Question 35

in order to reconstruct an image acquired using parallel imaging which of the folloiwng may be required

Answer 35

reference or calibration scan

Question 36

when using parallel imagin to reduce acqwuisition times, which of the followoing is always true

Answer 36

SNR is not affected unless the accelertion factor is greater than 2