physics quizzes

Question 1

When the RF pulse is applied the Net Magnetic Value Vector Flips into the ________plane

Answer 1

Transverse

Question 2

Once the RF pulse is removed Mo realigns to Bo and the created transverse magentization decays.

Answer 2

true

Question 3

The F.I.D. can be defined as. (Select all that apply)

Answer 3

A. Signal after the R.F. pulse is removed

B. Primary signal

C. Dephasing Hydrogen Protons

Question 4

In order for resonance to occur the RF Pulse needs to match the exact precessional Frequency of Hydrogen Atoms

Answer 4

True

Question 5

In the presence of a Magnetic Field a spinning proton

Answer 5

Precesses

Question 6

This signal is the intial signal recieved after the 90 degree excitation pulse.

Answer 6

F.I.D.

Question 7

Transverse Magnetization decreases after the intial excitation pulse is removed

Answer 7

True

Question 8

When Hydrogen Atoms are termed In Phase it refers to the precessing magnetic moments being

Answer 8

On the same point in their Precessional Path

Question 9

A moving charged particle induces a magnetic field in a plane parallel to its motion

Answer 9

False

Question 10

A unit of electrical charge is measured in

Answer 10

Coulomb

Question 11

Control of TE is exercised by control of

Answer 11

T2 relaxation time

Question 12

Free Induction decay is ad RF wave that is emitted from the patient

Answer 12

True

Question 13

In order for resonance to occur what has to happen

Answer 13

Precessional Frequency and RF pulse must match

Question 14

T1 and T2 times occur at the same time

Answer 14

True

Question 15

T1 is also termed

Answer 15

Longitudinal Relaxation

Question 16

T2 is also termed

Answer 16

Transverse Relaxation

Question 17

The Fourier Transform of the FID results in a nuclear magnetic spectrum which is in the frequency domain

Answer 17

True

Question 18

The induced signal from the patient decreases with time as the proton spins relax

Answer 18

True

Question 19

The time between the initial 90 degree pulse and the Peak signal is called

Answer 19

TE

Question 20

The time from the initial 90 degree RF pulse to the next RF pulse is termed?

Answer 20

repition time

Question 21

In phase is also called?

Answer 21

coherent

Question 22

Phase is measured in____________

Answer 22

radians of degrees

Question 23

—Frequency is the unit of occurrence or frequency and is measured as Hertz (Hz).

Answer 23

true

Question 24

Hydrogen Nuclei start to Recover back to Bo or the Longitudinal Plane, they are now Out of Phase

Answer 24

true

Question 25

—T1 recovery(spin lattice relaxation) is the relaxation time for 67% of the Net magnetization of the tissue to recover.

Answer 25

false

Question 26

—The T2 relaxation time is the time it takes for tissue to decay in the transverse plane to 37% (or 63% to be lost)

Answer 26

true

Question 27

The time from the initial 90 degree RF pulse to the next RF pulse is termed?

Answer 27

repition time

Question 28

Know as the father of MRI

Answer 28

felix bloch

Question 29

When the protons return to their "normal" state in the longitudinal plane (Z) after being excited by the RF pulse this is called.

Answer 29

equilibrium

Question 30

The 90 degree RF pulse is also called the \_\_\_\_\_\_\_\_\_\_\_\_\_\_.

Answer 30

flip angle

Question 31

Number of Protons in the Nucleus is termed.

Answer 31

Atomic Number

Question 32

In the presence of a Magnetic Field a spinning proton

Answer 32

precesses

Question 33

At 1 Tesla the gyromagnetic ratio of hydrogen is

Answer 33

42.57 Mhz

Question 34

A Vector is a quantity that has

Answer 34

magnitude and direction

Question 35

When a patient is subjected to a strong magnetic field the patient becomes polarized and has

Answer 35

Net Magnetization

Question 36

Precession Frequency depends on what factor(s)

Answer 36

Type of atoms nucleus. Strength of Bo

Question 37

Who is considered by most to be the father of MRI

Answer 37

Felix Bloch

Question 38

Once the Hydrogen nuclei are subjected to a external magnetic field they start to\_\_\_\_\_\_\_\_\_\_.

Answer 38

Wobble Line up with or against the field Precess

Question 39

A Magnetic Field is created when (select two)

Answer 39

A charged particle moves Current is moving along a path of wire

Question 40

Hydrogen contains its own large magnetic moment due to the odd number of Protons in the Nucleus

Answer 40

True

Question 41

With no exposure to a Magnetic Field, Magnetic moments are randomly situated

Answer 41

True

Question 42

Once a Magnetic Moment is exposed to an external Magnetic Field it will line up with or against the external field.

Answer 42

True

Question 43

Spin up Nuclei contain energy that are

Answer 43

low

Question 44

Spin down Nuclei contain energy that is

Answer 44

high

Question 45

Net Magnetization Vector (N.M.V.) is the result of

Answer 45

A battle between Spin Up and Spin Down Nuclei

Question 46

In order for resonance to occur the RF Pulse needs to match the exact precessional Frequency of Hydrogen Atoms

Answer 46

True

Question 47

Once a Magnetic Moment is exposed to an external Magnetic Field it will line up with or against the external field.

Answer 47

true

Question 48

This signal is the intial signal recieved after the 90 degree excitation pulse.

Answer 48

FID

Question 49

When Hydrogen Atoms are termed In Phase it refers to the precessing magnetic moments being

Answer 49

On the same point in their Precessional Path

Question 50

In order for resonance to occur the RF Pulse needs to match the exact precessional Frequency of Hydrogen Atoms

Answer 50

True

Question 51

Precessional Frequency of any atom that meets the criteria for MRI, we must know what two things.

Answer 51

The gyro magnetic ratio of that atom at 1 T Strength of Bo

Question 52

The F.I.D. can be defined as

Answer 52

Signal after the R.F. pulse is removed Primary signal Dephasing Hydrogen Protons

Question 53

Once the RF pulse is removed Mo realigns to Bo and creates magentization decays

Answer 53

True