Coils

Question 1

Electromagnetic components of RF System maybe provided by outside supplier and assemble by MRI manufacture

Answer 1

RF SYSTEM

Question 2

2 Coils

Answer 2

SHIM COILS -MAKE MAGNETIC FIELD HOMOGENEOUS
RECEIVER COILS-DETECT THE RETERNING RADIOSIGNAL ARE ‘ANTENNA’ OF THE MRI SYSTEM THE BROADCAST

Question 3

4 TYPES OF COILS

Answer 3

SURFACE COILS, PAIRED SADDLE COIL, HELMHORTZ PAIR COIL, BIRDCAGE COIL

Question 4

use are the simply loop of wire either circular or RECTANGULAR

Answer 4

Surface coil

Question 5

• Provide better homogeneity of RF in area of interest

Answer 5

PAIRED SADDLE COIL

Question 6

consis of two circular coils parallel

Answer 6

HELMHORTZ PAIR COILS

Question 7

• Transceiver coil for imaging of the head

Answer 7

BIRD CAGE COIL

Question 8

What are the Power supply of MRI

Answer 8

2.4Kw, 5% voltage ripple, 1.5 Tesla commonly used

Question 9

Use ALUMINUM, FORM OF SHEILD FARADAY CAGE, PRETECTION THE VERY WEAK RF SIGNAL

Answer 9

FARADAY CAGE

Question 10

Is used in MRI to describe the relative contribution detected signal of background noise

Answer 10

SNR/SIGNAL NOISE RATIO

Question 11

IF SNR WILL INCREASE
FACTOR AFFECTING SNR

Answer 11

BO,T1,T2,TE,TR,FOV,nex,matrix size, RF BANDWIDTH, PIXEL SIZE, SLICE THICKNESS

Question 12

6 INCREASE IN FACTORS AFFECTING SNR

Answer 12

BO,TR,T2,FOV,RF BANDWIDTH,PIXEL SIZE, SICE THICKNESS

Question 13

4DECREASE IN FACTORS AFFECTING SNR

Answer 13

T1,TE,NEX,MATRIX SIZE

Question 14

Types of IF ALL PARAMETERS ARE CONSTANT/bandwidth

Answer 14

RF COIL,RF BANDWIDTH,THE RECEIVER (ACQUISITION)BANDWIDTH,THE TRANSMIT BANDWIDTH,PULSE SEQUENCE

Question 15

IF ALL PARAMETERS ARE CONSTANT

• smaller sensitive volume of coil,local coil or better amd selected SLICE PLANE

Answer 15

RF COIL

Question 16

• refers the frequencies associated either with RF excitation

Answer 16

RF BANDWIDTH

Question 17

Range of frequencies accepted by the receiver to sample MR signal

Answer 17

THE RECEIVER (ACQUISITION)BANDWIDTH

Question 18

Slice selection in pulse sequence, slice thickness, lowering the PULSE

Answer 18

THE TRANSMIT BANDWIDTH

Question 19

• Acquire images with different tissue contrast mechanism

Answer 19

PULSE SEQUENCE

Question 20

• MRI uses technology is called?

Answer 20

Pulse sequence

Question 21

diffusion movement of molecules due to random motion

Answer 21

Diffusion weighted imaging(DWI)-

Question 22

How many hours in DWI/Diffusion weighted imaging in prior scan

Answer 22

72HOURS prior scan

Question 23

What will use in DWI?

Answer 23

used CVA/ CARDIOVASCULAR ACCIDENT and CNS/CENTRAL NERVOUS SYSTEM

Question 24

In what signal diffusion values in DWI

Answer 24

T2

Question 25

WHAT IS THE DWI REMAINS SENSITIVE ?

Answer 25

T1AND T2 RELAXATION

Question 26

Most widely used start in 90pulse and ends of 180 degree pulse

Answer 26

SPIN ECHO

Question 27

Refocus the spin gradient echo are more susceptible to blood flow 90° in additional TRand TE, Aka reverse the polarity of gradient

Answer 27

GRADIENT ECHO

Question 28

How many flip angles of GRADIENT ECHO

Answer 28

LESS THAN 90°

Question 29

2FAST PULSE SEQUENCE

Answer 29

Fast gradient echo(FGRE),FAST SPIN ECHO (FSE)

Question 30

For turbulent blood flow

Answer 30

Fast gradient echo(FGRE)

Question 31

is quicker because it is cover wide range of tissue used start in 90pulse and ends of 180 degree pulse

Answer 31

FAST SPIN ECHO(FSE)