MRI Quiz - Parameters Increase/Decrease

Question 1

↑TE

Answer 1

↓ ↑i = = │ ↑T2 ↓ # slices

Question 2

Decreasing bandwidth by factor of 2 increases SNR by:

Answer 2

√2 (approximately 40%)

Question 3

TSE (ETL) increased by factor of 2, then the scan time:

Answer 3

Will be 2 times faster

Question 4

↑ETL/TSE

Answer 4

↓ ↓ = ↑ │ ↑blurring

Question 5

↑PI reduction factor

Answer 5

↓ ↓ = ↓ │ ↓DWI susceptibility

Question 6

If the repetition time (TR) is doubled, the scan time will:

Answer 6

Double

Question 7

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

Answer 7

Factor of 4

Question 8

↑# SAT bands

Answer 8

↓ ↑ = ↑ │ ↓motion/flow artifacts

Question 9

Doubling field strength results in ____fold increase in SAR potential

Answer 9

4

Question 10

As the flip angle is doubled, the RF absorption (deposition) increases by:

Answer 10

Factor of 4

Question 11

↑Phase Matrix

Answer 11

↓ ↑ ↑ ↑i │ ↓truncation artifacts

Question 12

↑# of slices Acquired

Answer 12

= ↑ = ↑ │ ↑anatomic coverage

Question 13

↑TR

Answer 13

↑ ↑ = ↓ │ ↓T1 ↑ # slices

Question 14

↑TI

Answer 14

↓ ↑ = = │ ↑tissue saturation

Question 15

↑FOV

Answer 15

↑ = ↓ = │ ↑coverage area

Question 16

↑NSA/NEX

Answer 16

↑ ↑ = ↑ │ ↑motion?

Question 17

Each additional 180° RF pulse in FSE implements ____ times the SAR power compared to the initial 90° RF excitation pulse

Answer 17

4

Question 18

When going from a linear coil to a quadrature (CP) coil, SNR is increased by:

Answer 18

40%

Question 19

When increasing NEX/NSA, SNR (signal-to-noise ratio) increases by:

Answer 19

Square root (√) of the % increase

Question 20

↑Slice Thickness

Answer 20

↑ = ↓ = │ ↑partial volume artifacts

Question 21

↑Flip Angle

Answer 21

↑ = = ↑ │ ↓susceptibility

Question 22

↑DWI b-value

Answer 22

↓ ↑ = = │ ↑detection of stroke/neoplasm

Question 23

↑rBw

Answer 23

↓ ↓ = = │ ↓chemical shift & metal artifacts

Question 24

Doubling FOV increases SNR ____ times

Answer 24

4, due to the pixel size increase by a factor of 4 (phase and frequency dimensions)

Question 25

Doubling the magnetic field strength will ______ the SNR:

Answer 25

Double