MR ANGIOGRAPHY, DIFFUSION & PERFUSION

Question 1

In a spin echo sequence, normal flow will appear as:

Answer 1

A signal void

Question 2

Flow compensation only compensates for:

Answer 2

Laminar Flow

Question 3

In a gradient echo sequence, norma flow will appear as:

Answer 3

High signal

Question 4

The contrast mechanism for TOF MR is:

Answer 4

Flow related enhancement

Question 5

In a 2D TOF, the slices are acquired

Answer 5

Sequentially

Question 6

The most common post processing technique used for MRA studies to produce multiple views mimicking conventional angiograms is:

Answer 6

Maximum Intensity Projection

Question 7

Optimum signal due to flow is achieved when the blood flow is:

Answer 7

Perpendicular to the slice plane

Question 8

All of the following are an advantage of 3D TOF VS 2D TOF EXCEPT:

Answer 8

Best for imagining slow flow

Question 9

In order to increase coverage in a 3D TOF exam without saturating flowing spins, what technique may be employed?

Answer 9

Acquiring multiple small overlapping slabs

Question 10

The contrast mechanism for phase contrast MRA is

Answer 10

Velocity induced phase shifts

Question 11

With a phase contrast sequence, to optimize the signal from flow for a given velocity, the operator will modify what?

Answer 11

VENC

Question 12

What MRA technique is the best for imaging slow flow?

Answer 12

3D phase contrast

Question 13

What type of pulse sequence is commonly utilized for contrast enhanced MRA (CE-MRA)?

Answer 13

Spoiled gradient echo

Question 14

For a CE-MRA exam, it is important that the maximum concentration of the gadolinium coincides with:

Answer 14

the acquisition of low frequency data

Question 15

What is a preferred method for filling K-space for a CE-MRA acquisition?

Answer 15

Centric

Question 16

What timing method uses a small bolus in a separate injection of MRA acquisition?

Answer 16

Test bolus

Question 17

What pulse sequence is most commonly used for diffusion?

Answer 17

Spin echo EPI

Question 18

What b-value wold result in the greatest diffusion weighting?

Answer 18

1200, Higher b-value

Question 19

A major reason for producing ADC image is:

Answer 19

To remove the effects of T2 shine through

Question 20

When performing perfusion imaging with a gadolinium contrast agent, the result of the bolus flowing through the brain in the first pass is:

Answer 20

Decreased signal

Question 21

What sequence is most commonly used to acquire a perfusion study utilizing bolus of gadolinium contrast agent?

Answer 21

Gradient echo EPI