Chapter 1- Basic Principles

Question 1

There are two different views of MRI and they are :

Answer 1

Quantum theory and classical

Question 2

The classical theory focuses more on how the universe works “mechanically”

Answer 2

True

Question 3

The quantum theory focuses more on the different energy levels of protons and neutrals and electrons

True or False?

Answer 3

True

Question 4

An atom is organized into “____” which are two or more atoms arranged together?

Answer 4

a molecule

Question 5

In humans, the most abundant atom is hydrogen.

True or False

Answer 5

True

Question 6

An atom consists of a central nucleus and orbiting ___

Answer 6

electrons

Question 7

Protons and neutrons are subcategories of

Answer 7

nucleons

Question 8

the sum of the protons in a nucleus is called

Answer 8

anomic number

Question 9

The sum of the protons and neutrons in a nucleus is called the

Answer 9

mass number or atomic weight

Question 10

When an atom has less neutrons than protons this is called an

Answer 10

isotope

Question 11

Electrons are particles that spin around the nucleus

True or False

Answer 11

True

Question 12

Protons have a ____ electrical charge

positive, negative or none

Answer 12

positive

Question 13

Neutrons have a ____ electrical charge

positive, negative or none

Answer 13

No net charge

Question 14

Electrons have a ____ electrical charge

positive, negative or none

Answer 14

negative

Question 15

An atom is considered electrically stable if the number of electrons ____ the number of protons?

equals, is less, is more

Answer 15

equals

Question 16

How can we alter the balance of an electrically stable atom?

Answer 16

apply energy to knock out the electrons from the atom. This will produce electrical instability.

This is called an ION

Question 17

the process of knocking out electrons is called

Answer 17

ionization

Question 18

What are the three types of motion in an atom?

Answer 18

Electrons spinning in their own axis

electrons orbiting the nucleus

the nucleus spinning on its own axis.

Question 19

If an atom has an even atomic and mass number, (6 protons 6neutrons mass 12), will it have a spin?

Answer 19

no

if they have an even number , half the nucleons spin one direction and the other half another direction which cancels itself out??

Question 20

How is angular momentum caused?

Answer 20

in nuclei with an odd number of protons, odd number of neutrons, the spin directions are not equal and opposite so it will have a net spin.

Question 21

What is the large magnetic field of the MRI scanner called?

Answer 21

B 0

Question 22

What is the magnetic field measured in ?

Answer 22

teslas

Question 23

The influence of B 0 prouces an additional spin or wobble of the magnetic moment of hydrogen around b0.

Answer 23

True

Question 24

What is another name for precessional frequency?

Answer 24

Larmor Frequency

Question 25

What does RF stand for?

Answer 25

radiofrequency

Question 26

How would you explain “phase”

Answer 26

it refers to the position of magnetic moments on their precessional path at any moment in time.

Question 27

The magnetic moment travels thru 360 degrees during one rotation.

True or False

Answer 27

True

Question 28

What is the difference in out of phase and in phase?

Answer 28

In phase means the magnetic moment of hydrogen are at the SAME place on the precessional path at the moment in time

Out of phase means the magnetic moments of hydrogen are at DIFFERENT places on the precessional path.

Question 29

Out of phase is also called ____

Answer 29

incoherent

Question 30

in phase is also called

Answer 30

coherent.

Question 31

Resonance is also called “reverb”

Answer 31

True

Question 32

Resonance is achieved by transmitting an RF pulse called a ____

Answer 32

RF excitation pulse

Question 33

Excitation means “energy giving”

Answer 33

True

Question 34

A RF exciation pulse ____ energy to hydrogen nucleu and causes a net ___ to the number of high energy spin down nuclei

Takes energy/ gives energy

net increase or net decrease.

Answer 34

it gives energy to cause a net increase

Question 35

The process at which hydrogen loses its energy is called

Answer 35

relaxation

Question 36

Explain what TR is

Answer 36

TR is the time from the application of one RF excitation pulse for each slice.

Question 37

TR is measured in seconds

True or False

Answer 37

FALSE

Tr is measured in milliseconds

Question 38

TR determines the amount of longitudinal relaxation that occurs between the end of 1 RF pulse to the next.

True or False

Answer 38

True

Question 39

Explain what TE is

Answer 39

The time from the application of the RF pulse to the peak of signal induced in the receiver coil.

Question 40

TE is measured in milliseconds.

True or False

Answer 40

True

Question 41

TE determins how much decay of transverse magnetization occurs.

Answer 41

True

Question 42

TE controls the amount of T2 relaxation.

Answer 42

True