Chapter 1: Basic principles

Question 1

Classical Theory

Answer 1

Isaac Newton
-uses the concept of mass, spin, and angular moment on a large scale

Question 2

Quantum theory

Answer 2

Plank, Einstein, Durac
- operates on a subatomic scale and refers to the energy of protons, neutrons, and electrons

Question 3

hydrogen

Answer 3

the most abundant in the human body
- mostly found in the molecule of fat and water

Question 4

atomic mass

Answer 4

protons + neutrons = nucleons

Question 5

Heisenberg’s uncertainty principle

Answer 5

the position of an electron is not predictable because it depends on its energy

Question 6

isotopes

Answer 6

atoms with odd mass number

Question 7

ions

Answer 7

atoms that have excess of are deficient in electrons

Question 8

ionization

Answer 8

process of knocking electrons from the atom which causes an electrical imbalance

Question 9

MRI is based on

Answer 9

nuclear spin of hydrogen

Question 10

motion present in the atom (3)

Answer 10

• electron spin on their own axis
• electrons orbit the nucleus
• nucleus spins on its own axis

Question 11

nucleus doesn’t have spin if

Answer 11

it has an even number of atomic and mass numbers

Question 12

net spin/ angular moment

Answer 12

spin directions are not equal and opposite

Question 13

isotope of hydrogen

Answer 13

protium

Question 14

MR active nuclei have

Answer 14

net electrical charge (electric field) and are spinning (motion)

Question 15

magnetic field created by

Answer 15

charged moving particle
- this creates an electric field

Question 16

hydrogen nuclei act like

Answer 16

magnets
- they have an north and south pole

Question 17

B0

Answer 17

main static magnetic field

Question 18

alignment

Answer 18

when hydrogen is placed in a strong magnetic field and they orient to it

Question 19

3 fundamental ideas

Answer 19

• signal strength proportional hydrogen density
• Larmor frequency proportional to magnetic field strength
• spin needs time to realign with magnetic field (relaxation time)

Question 20

parallel

Answer 20

magnetic moment aligned in same direction as B0 field
- spin up

Question 21

anti-parallel

Answer 21

magnetic moment are in opposite direction of the B0
- spin down

Question 22

NVM

Answer 22

net magnetic vector
- net magnetization of the patient
- aligned parallel to B0
- in longitudinal plan (z-axis)

Question 23

Hydrogen nuclei energy states

Answer 23

low and high energy

Question 24

Low energy

Answer 24

does not have enough energy to oppose B0 field
- spin up

Question 25

High energy

Answer 25

has enough energy to oppose B0 field - spin down

Question 26

thermal equilibrium

Answer 26

patient temp is constant and doesn't influence the thermal energy

Question 27

precession

Answer 27

each hydrogen nuclei spins on its own axis

Question 28

Larmor Frequency

Answer 28

precessional refquency equation

Question 29

hydrogen at 1 Tesla

Answer 29

42.58

Question 30

1 Tesla to Gauss

Answer 30

1T= 10,000 Gauss

Question 31

Michael Faraday

Answer 31

law of electromagnetic induction - refers to the connection between electric and magnetic fields and motion - moving electric field produces a magnetic field

Question 32

Boltzmann's equation

Answer 32

patient's thermal temp is an important factor that determines spin is in high or low energy population

Question 33

phase

Answer 33

position of magnetic moment on their processional path at any time

Question 34

unit of phase

Answer 34

radian

Question 35

frequency

Answer 35

rate of change in the phase