Part II

Question 1

MRI basic principles [requirements]

Answer 1

Magnetic field (Mo) of hydrogen atoms
magnetic field (Bo) off the gradient coils
radio frequency by the RF coils
Added magnetic field by outer magnets

Question 2

Precession is due to [..]

Answer 2

Angular momentum

Question 3

The orientation of Z plane follows the orientation of the [..]

Answer 3

Bo

Question 4

Spin of the nucleus, counterclockwise, reason for procession

Answer 4

Angular momentum

Question 5

[M] Ideally all proton would line up the same orientation because of the [..] of the nucleus

Answer 5

Thermal motion

Question 6

[M] At [..] approximately one proton in every million protons will be aligned with the magnetic field. Where are the rest cancel out

Answer 6

Room temperature

Question 7

Resonance

Answer 7

Property to respond to Larmour frequency
Property of the precessing nucleus in which it absorbs energy

Question 8

Degree of radio frequency is applied, and protons are flipped towards the transverse plane

Answer 8

90 to 180°

Question 9

The longer introduction of RF [..], the shorter introduction of RF [..]

Answer 9

Better
Blurred

Question 10

The energy collected by RF coils

Answer 10

Free induction decay

Question 11

Strength of FID = [..]

Answer 11

Area of Mxy

Question 12

Increase in FID = [..]

Answer 12

Increase brightness (hyperintense)

Question 13

Connected to computer system to convert signals to pulses

Answer 13

RF coils

Question 14

Movement of proton in nucleus

Answer 14

Proton density

Question 15

Concentration of H atoms

Answer 15

Spin density

Question 16

Identifies the tone of the tissue

Answer 16

Spin density

Question 17

Spin density of muscles and white matter

Answer 17

100

Question 18

Spin density of fat

Answer 18

98

Question 19

Spin density of CSF

Answer 19

96

Question 20

Spin density of kidney

Answer 20

95

Question 21

Spin density of gray matter

Answer 21

94

Question 22

Spin density of spleen

Answer 22

92

Question 23

Spin density of liver

Answer 23

91

Question 24

Spin density of blood

Answer 24

90

Question 25

Spin density of pancreas

Answer 25

86

Question 26

Spin density of cortical bone

Answer 26

1 to 10

Question 27

Spin density of lungs

Answer 27

1-5

Question 28

Spin density of air

Answer 28

<1

Question 29

Most used particle in MRI, one proton is its nucleus

Answer 29

Protium

Question 30

One proton, one neutron

Answer 30

Deotirium

Question 31

Three particles, two neutron one proton

Answer 31

Tritium

Question 32

Image formation of conventional radiation

Answer 32

Expose – transmit/absorption – IR

Question 33

Image formation of CT

Answer 33

Expose – transmit/absorb – detectors

Question 34

Image formation of MRI

Answer 34

Expose – absorb– release – RF coils

Question 35

Advantages of MRI

Answer 35

Tissue contrast – hi did you mean by signals received Information content of MR image - range of pathology may be identified Sensitivity and specificity -high spatial resolution Energy -non ionizing