Intro

Question 1

Volume coil transmitter and receiver? common structure? SNR? area large/ small? eg?

Answer 1

transceivers, quadrature, good SNR, large, body coil

Question 2

linear phase array SNR? area large/ small? eg?

Answer 2

good SNR, large area, spine coil

Question 3

volume phased array aka? advantage? # of coil=?

Answer 3

parallel imaging, dec scan time, reduction factor

Question 4

surface coil SNR? area large/ small?

Answer 4

good SNR, small area near skin surface

Question 5

methods to inc SNR in terms of:

• SE or GRE
• TR long or short
• TE long or short
• FA
• matrix coarse or fine
• FOV small or large
• slices thin or thick
• rBW narrow or wide
• NEX high or low

Answer 5

• use SE/ FSE
• long TR
• short TE
• FA 90°
• coarse matrix
• large FOV
• thick slices
• narrow rBW
• high NEX

Question 6

SE
TR short ___, long ___
TE short ___, long ___

Answer 6

TR short 600-800, long 2000+

TE short <30, long 70+

Question 7

FSE
TR short ___, long ___
TE short ___, long ___
ETL short ___, long ___

Answer 7

FSE

TR short 400-600, long 4000+
TE short <20, long 90+
ETL short 2-6, long 16+

Question 8

IR T1
TR \_\_\_, \_\_\_
TE \_\_\_, \_\_\_
TI \_\_\_
ETL \_\_\_, \_\_\_

Answer 8

IR T1
TR long 3000+
TE short <20
TI 200-600
ETL short 2-6

Question 9

STIR
TR \_\_\_, \_\_\_
TE \_\_\_
TI \_\_\_, \_\_\_
ETL \_\_\_

Answer 9

STIR
TR long 3000+
TE 60+
TI short 100-175
ETL 16+

Question 10

FLAIR
TR \_\_\_, \_\_\_
TE \_\_\_, \_\_\_
TI \_\_\_, \_\_\_
ETL \_\_\_

Answer 10

FLAIR
TR long 9000+
TE long 80+
TI long 1700-2500 ms
ETL 16+

Question 11

Coherent GRE
TR ___, ___
TE ___, ___
FA ___

Answer 11

Coherent GRE
TR short <50
TE long 15+
FA 20-50°

Question 12

Incoherent GRE
TR ___, ___
TE ___, ___
FA ___

Answer 12

Incoherent GRE
TR short <50
TE short min
FA 20-50°

Question 13

Balanced GRE
FA ___
TR ___
TE ___

Answer 13

Balanced GRE
FA >40°
TR min
TE min

Question 14

methods to inc CNR in terms of:

• contrast or no
• T1 or T2 or PD
• tissue signal
• flow

Answer 14

• contrast
• T2
• null tissues (STIR, FLAIR, MTC)
• enhance flow (eg. TOF)

Question 15

four ways to suppress tissues

Answer 15

1. sequences (STIR, FLAIR)
2. chemical pre-saturation
3. spectral pre-saturation (IR)
4. dixon

Question 16

3 ways to inc res

Answer 16

• thin slices
• fine matrix
• small FOV

Question 17

3 ways to dec scan time

Answer 17

• short TR
• coarse phase matrix
• low NEX

Question 18

3D imaging

- has extra freq or phase encoding along slice dir?

Answer 18

phase

Question 19

3D imaging scan time depends on?

Answer 19

TR, matrix, NEX, # of slices

Question 20

3D imaging needs what IO?

Answer 20

oversampling to avoid wrap

Question 21

advantages and disadvantages of inc TR?

Answer 21

• inc SNR and slice #

- inc scan time and dec T1 contrast

Question 22

advantages and disadvantages of inc TE?

Answer 22

• inc T2 contrast

- dec SNR

Question 23

advantages and disadvantages of inc NEX?

Answer 23

• inc SNR and less motion artifact

- inc scan time

Question 24

advantages and disadvantages of inc slice thickness?

Answer 24

• ins SNR and coverage

- dec res

Question 25

advantages and disadvantages of inc FOV?

Answer 25

• inc SNR and coverage

- dec res and aliasing more likely

Question 26

advantages and disadvantages of inc matrix?

Answer 26

• inc res

- dec SNR and inc scan time

Question 27

advantages and disadvantages of inc rBW?

Answer 27

• dec min TE and chem shift

- dec SNR

Question 28

FSE pulses

Answer 28

FSE:

- 90° excitation pulse followed by several 180° rephasing pulses

Question 29

SS-FSE aka?

Answer 29

HASTE

long ETL to fill k-space in one shot with half-Fourier (acquire only half and transpose the other half

Question 30

intensity of fat on T2 FSE?

Answer 30

bright

Question 31

muscle intensity on T2 FSE? why?

Answer 31

darker due to MT

Question 32

what artifact is prone with FSE with long ETL? how to reduce and what is trade off?

Answer 32

• blurring

- dec FOV in phase dir or use broader rBW but dec SNR