IMAGE QUALITY & ARTIFACTS

Question 1

What will result in an increase of saturation of tissues?

Answer 1

Reducing the TR from 1000 msec to 200 msec

Question 2

What suppression technique utilizes an additional RF pulse applied at a specific range of frequencies?

Answer 2

Spectral Pre-saturation

Question 3

For adequate and uniform RF fat suppression (spectral pre-saturation) is required?

Answer 3

Homogenous field

Question 4

When fat suppression is desired over the entire FOV of a coronal hip sequence, what technique will likely result in the most uniform fat suppression?

Answer 4

STIR

Question 5

The injection of gadolinium-based contrast agent, what technique is NOT recommended?

Answer 5

STIR

Question 6

What technique for fat suppression can be successfully utilized at AL field strengths following the injection of gadolinium?

Answer 6

Dixon Method

Question 7

The human eye perceives:

Answer 7

Contrast to Noise

Question 8

Reducing the slice thickness by a factor of 2, will reduce the voxel volume by a factor of:

Answer 8

2

Question 9

Reducing the FOV by a factor of 2 will reduce the voxel volume by a fact of:

Answer 9

4

Question 10

Increasing the RBW by a factor of 2 will result in:

Answer 10

Increase in noise by a factor of the square root of 2

Question 11

Decreasing the RBW by a factor of 2 will result in:

Answer 11

Increase in SNR by a factor of 2

Question 12

To increase the SNR by a factor of 2, increase the NSA by a factor of:

Answer 12

4

Question 13

To eliminate aliasing, what option would be selected?

Answer 13

Utilize an over sampling technique

Question 14

Truncation artifact can be reduced by:

Answer 14

Increasing the number of high frequency samples

Question 15

Utilizing a gradient echo sequence, what parameter can be adjusted to produce an out of phase image?

Answer 15

TE

Question 16

To reduce the amount of pixel shift seen in an image what should be done?

Answer 16

Increase the RBW

Question 17

Assuming identical scan parameters, what field strength would result in the least chemical shift artifact?

Answer 17

0.3T

Question 18

Chemical shift is seen along the:

Answer 18

Frequency encoding direction

Question 19

What RBW would result in a smaller signal void associated with a metallic clip?

Answer 19

Bigger, 32 kHz

Question 20

Motion is seen as ghosting along the:

Answer 20

Phase encoding direction

Question 21

Which slice gaps would result in the least cross talk?

Answer 21

0.2mm, bigger