Chapter 8

Question 1

When using MRA to evaluate intracranial vascularity, flow within smaller vessels can best be demonstrated by:

Answer 1

3D Time of Flight MRA

Question 2

What determines the length of the R to R interval?

Answer 2

The patient’s heart rate

Question 3

If the R to R interval is 500 ms, the trigger window is 10%, and the trigger delay is 50 ms, what is the time available to acquire data?

Answer 3

400 ms

Question 4

What is the waiting period after each R wave called?

Answer 4

Trigger Delay

Question 5

Which of the following best describes what the “P” wave represents?

Answer 5

Atrial Systole (Contraction)

Question 6

What is the available imaging time using these parameters? R to R 800 ms, trigger window 10%, delay after trigger 4 ms.

Answer 6

716 ms

800- 80 - 4 = 716 ms

Question 7

The vascular signal, produced on PC-MRA, relies on:

Answer 7

Velocity-induced phase shifts

Question 8

How much does a typical patient’s heart rate vary during an exam?

Answer 8

10- 20 %

Question 9

The vascular signal, produced on time of flight MRA (TOF-MRA), relies on:

Answer 9

Flow related enhancement

Question 10

Which of the following does NOT reduce flow motion artifact?

Answer 10

Subtraction

Question 11

Which of the following best describes what the “QRS” complex represents?

Answer 11

Ventricular Systole

Question 12

Generally, 3D TOF-MRA acquisitions are optimal for high resolution, for the evaluation of:

Answer 12

Smaller vessels with high velocity blood flow (intracranial vessels associated with the Circle of Willis, COW)

Question 13

The signal from flowing blood within vessels in MRI and MRA relies on:

Answer 13

First order motion

Question 14

In spin echo sequences using a pre-saturation pulse, what would persistent bright signal within the vessel indicate?

Answer 14

Vascular Occlusion
Blood Clot
Slow Flowing Blood

Question 15

What is the waiting period before each R wave called?

Answer 15

Trigger Window

Question 16

Which of the following sequence(s)/techniques(s) can be used to produce images where vessels appear dark?

Answer 16

The Application of Pre-Sat Pulses

Spin Echo Acquisitions

Question 17

When using MRA to evaluate extracranial vascular flow, such as that within common carotid arteries, a recommended technique is:

Answer 17

2D time of flight MRA

Question 18

Which of the following best describes what the “T” wave represents?

Answer 18

Ventricular Diastole (Relaxation)

Question 19

Which of the following is used to trigger each pulse sequence when using ECG gating?

Answer 19

R wave

Question 20

ECG gating is prospective. (T or F)

Answer 20

true

Prospective- the scan is time to and triggered from the beats of the heart during acquisition

Question 21

Multiphase images, acquired with additional modulation of magnetization, are known as:

Answer 21

SPAMM

Question 22

Contrast enhanced MRAs are acquired with all of the following EXCEPT:

Answer 22

VENC settings

Question 23

Which of the following sequence(s)/technique(s) can be used to make vessels appear bright?

Answer 23

Contrast Enhancement
Gradient Moment Rephasing
Gradient Echo Imaging
(all of the above)

Question 24

Which of the following can be used to improve coverage and at the same time maintain the signal from blood flowing within the larger volume?

Answer 24

MOTSA

Question 25

MRA techniques include all of the following EXCEPT:

Answer 25

CT-MRA

Question 26

When using MRA to evaluate peripheral vascular flow, such as that within the arteries of the legs, saturation pulses are:

Answer 26

Placed inferior to the acquired slices Saturation pulses can be used to suppress the signal from venous blood to allow for better visualization of arterial flow.

Question 27

How much do most patient's heart rate vary during the scan?

Answer 27

10-20%

Question 28

What position in the chest does the heart lie?

Answer 28

double oblique

Question 29

where is base of heart

Answer 29

located superiorally

Question 30

where is apex of heart

Answer 30

located inferiorally

Question 31

where is atrial septum

Answer 31

separates atria

Question 32

where is ventricular septum

Answer 32

separates ventricles

Question 33

prospective gating

Answer 33

scan is triggered from beats of heart, uses R-R

Question 34

retrospective gating

Answer 34

after scan is completed

Question 35

MOTSA

Answer 35

maintain signal and improve coverage w large volume

Question 36

MIP

Answer 36

projects maximum intensity

Question 37

SSD

Answer 37

surface is presented on the reformated data as though illiminated by directional light source

Question 38

SPAMM

Answer 38

spatial modulation of magnet

Question 39

3D TOF MRA

Answer 39

high resolution, evaluation of smaller vessles w high velocity blood flow (COW)

Question 40

2D TOF MRA

Answer 40

slow velocity w large FOV (carotids, venous)

Question 41

vessel appearance spin echo with pre-saturation

Answer 41

black blood

Question 42

vessel appearance gradient echo with GMN

Answer 42

bright blood

Question 43

vessel appearance peristant signal within a vessel lumen after the application of a SAT pulses

Answer 43

slow flow. Ex (blood clot or vascular occlusion

Question 44

parameters used in gating : T1 weighting

Answer 44

1 R-R interval, short TE

Question 45

parameters used in gating : PD weighting

Answer 45

2-3 R-R intervals, short TE

Question 46

parameters used in gating : T2 weighting

Answer 46

2-3 R-R intervals, long TE

Question 47

What is the equation for available imaging time?

Answer 47

=R-R interval - (trigger window + trigger delay)

Question 48

Which are options for the optimization of scan timing

Answer 48

bolus tracking: tracker pulse measures signal from the lumen fluoro triggering: the operator witnesses the arrival of the contrast test bolus: small injection made to determine the exact time to begin scanning

Question 49

trigger window

Answer 49

waiting time before each R-R wave

Question 50

trigger delay

Answer 50

waiting period after each R-R wave

Question 51

Digital Subtraction MRA

Answer 51

2 T2 data sets, one during systolic and one during diastolic (fresh blood imaging)

Question 52

TOF MRA

Answer 52

enhancment related to the flow of blood

Question 53

PC MRA

Answer 53

signal relies on velocity-induced phase shifts

Question 54

contrast enhanced MRA

Answer 54

T1 3D gradient echo following by gad and dynamic imaging

Question 55

Which of the following statements concerning the safety of gating is correct?

Answer 55

Do not used frayed or splitting cables Do not loop or cross-over cables Make sure the cables do not touch the patient Place pads between the cables and the patient

Question 56

Calculate the correct dosage of gadolinium contrast for a 160-pound patient with normal renal function.

Answer 56

15 mL 165/2.2=75kg*0.2=15mL

Question 57

ECG

Answer 57

electrodes and wires placed on pts chest

Question 58

peripheral gating

Answer 58

placed on pts finger

Question 59

black blood

Answer 59

SE w pre-sats, inversion recovery

Question 60

bright blood

Answer 60

GRE, GMN, contrast enhancement