Module 1

Question 1

Bore

Answer 1

Opening through the magnet

Question 2

Isocenter

Answer 2

The middle of the magnet (sweet spot)

Question 3

Inhomogeneities

Answer 3

When space is erratic and makes variations

Question 4

Shimming

Answer 4

A means to make the field more homogenous

Question 5

Lines of force/flux

Answer 5

A magnetic field surrounds a current moving through a conductor.

Question 6

Active shims

Answer 6

Small coils that superimpose magnetic fields on the main magnet altering the flux density

Question 7

Parts per million

Answer 7

What deviation from perfection is measured as

Question 8

Passive shims

Answer 8

Used for permanent magnets. Curved iron poles on corners

Question 9

Quench

Answer 9

Gas expanding rapidly most likely to happen during the initial ramping after installation and it can happen multiple times

Question 10

Superconducting magnet

Answer 10

Utilizes a super cold liquid, cryogenic to chill an exotic conductor, niobium, to a temperature that allows the flow of electricity without resistance

Question 11

Quench pipe

Answer 11

Removes he from the room as quickly as possible

Question 12

Primary coil

Answer 12

Main magnet referred to as B sub zero

Question 13

Gradient coils

Answer 13

3 sets which enable spatial location

Question 14

Shim coils

Answer 14

Used for homogeneity

Question 15

RF probe

Answer 15

The radio frequency emits pulses of energy that excite Hydrogen atoms in the body

Question 16

Active shielding

Answer 16

Contains the periphery of the magnetic field called the fringe field to a smaller area

Question 17

Aperture

Answer 17

Opening diameter

Question 18

Nuclear magnetic resonance

Answer 18

Produces a spectrogram of energy released from protons after radio frequency excitation

Question 19

Gradient magnetic fields

Answer 19

Field that increases in strength over the distance it covers. (At a linear slope)

Question 20

Transceiver

Answer 20

Coils that can both transmit the RF pulse and receive the signal back

Question 21

Z gradient

Answer 21

Longitudinal

Question 22

Y gradient

Answer 22

Vertical

Question 23

X gradient

Answer 23

Transverse

Question 24

Proton density

Answer 24

Proportional to the strength of the MR signal

Question 25

Protium

Answer 25

The isotope of H with a single proton

Question 26

Precessional frequency

Answer 26

The frequency of rotation is dependent on the field of strength of the external field

Question 27

Radio frequency

Answer 27

Has the same Larmor frequency as H, irradiates tissue

Question 28

Mxy

Answer 28

The magnetization of the patient at equilibrium

Question 29

Net magnetization vector

Answer 29

Magnetic moments of individual active protons must add flux lines together to create a magnetic field that is strong enough to extend beyond the patients body and be detected

Question 30

Out of phase

Answer 30

Two protons processing in B sub zero. Each has a magnetic moment but their amplitude doesn’t add together.

Question 31

Resonance

Answer 31

The absorption of energy by a body, due to its frequency of oscillation being the same the frequency of another body’s oscillating is perturbed

Question 32

Resonant frequency

Answer 32

When there is a loss of amplitude but the frequency of the vibrations are still the same its called the

Question 33

Magnetic domain

Answer 33

At the resonant frequency H all active magnetic moments move to the same position on the processional path

Question 34

Free induction decay

Answer 34

After coming into phase the RF pulse terminates and this begins

Question 35

Flip angle

Answer 35

Determined by the amplitude and duration of the RF pulse

Question 36

Angular momentum

Answer 36

Net spin

Question 37

Dipole

Answer 37

Bipolar

Question 38

Helix

Answer 38

A wire conductor wrapped in coil

Question 39

Solenoid

Answer 39

Electric current flowing through a helix

Question 40

Spin quantum number

Answer 40

Each element has this and it signifies if it is active or not

Question 41

1 tesla

Answer 41

10,000 gauss

Question 42

1 tesla

Answer 42

10,000 gauss