Chapter 1

Question 1

What is the gyromagnetic ratio?

Answer 1

The speed of precession at 1.0T

Question 2

What are protons?

Answer 2

Positively charged elements of the atomic nucleus

Question 3

The Free Induction Decay (FID) signal occurs after the RF pulse is:

Answer 3

Turned off

Question 4

What does the Boltzmann equation predict?

Answer 4

The number of spins in each energy level

Question 5

The net magnetization vector (NMV) moves out of alignment due to:

Answer 5

RF Excitation

Question 6

What is the term for hydrogen nuclei aligning with B₀?

Answer 6

Parallel alignment

Question 7

What is the primary magnetic field of the MRI scanner denoted as?

Answer 7

B₀

Question 8

The ______________ field is responsible for the resonance in MRI.

Answer 8

B₁

Question 9

The process of energy absorption by hydrogen nuclei during an RF pulse is called:

Answer 9

Resonance

Question 10

What is Faraday’s Law?

Answer 10

It describes the connection of a magnetic field and an electric field in motion

Question 11

Which particles spin around the nucleus of an atom?

Answer 11

Electrons

Question 12

Which of the following refers to atoms with an odd mass number?

Answer 12

Isotopes

Question 13

The NMV is the net magnetic vector resulting from excess spin-up nuclei.

Answer 13

True

Question 14

What does the mass number of an atom represent?

Answer 14

Sum of protons and neutrons

Question 15

Which term describes the random motion of molecules contributing to MRI contrast?

Answer 15

Brownian motion

Question 16

What does the term “flip angle” refer to in MRI?

Answer 16

The angle at which the NMV is flipped relative to Bo

Question 17

What is the primary purpose of the repetition time (TR)?

Answer 17

Control T1 relaxation

Question 18

What is “Free Induction Decay” (FID)?

Answer 18

The loss of signal due to relaxation

Question 19

What does the echo time (TE) control?

Answer 19

T2 contrast

Question 20

The primary factor that determines the flip angle is:

Answer 20

Amplitude and Duration of RF Pulse

Question 21

The phenomenon in which hydrogen nuclei wobble when placed in a magnetic field is called:

Answer 21

Precession

Question 22

The ___________ time (TE) determines how much T2 relaxation has occurred.

Answer 22

Echo

Question 23

What is the term used to describe the spin of MRI-active nuclei?

Answer 23

Angular momentum

Question 24

The hydrogen nucleus used in MRI is called:

Answer 24

Protium

Question 25

What does ionization refer to?

Answer 25

The removal of electrons from an atom

Question 26

What is the unit of precessional frequency?

Answer 26

Megahertz (MHz)

Question 27

What does the atomic number of an element represent?

Answer 27

Sum of protons in the nucleus

Question 28

The stronger the external magnetic field (B₀), the:

Answer 28

Higher the precessional frequency

Question 29

The principle that explains how a changing magnetic field induces an electromotive force is called ___________.

Answer 29

Faraday's Law

Question 30

Which of the following is responsible for the MR signal production?

Answer 30

Coherent Transverse Magnetization

Question 31

What type of electromagnetic radiation is used in MRI to excite hydrogen nuclei?

Answer 31

Radiofrequency (RF)

Question 32

What are ions?

Answer 32

Atoms with an excess or deficit of electrons

Question 33

The NMV moves into the transverse plane due to:

Answer 33

RF Pulse Excitation

Question 34

What is the gyomagnetic ratio of hydrogen at 1 Tesla?

Answer 34

42.58 MHz

Question 35

Which theory explains MRI using mass, spins, and angular momentum?

Answer 35

Classical Theory

Question 36

The MR signal is detected in which plane?

Answer 36

Transverse

Question 37

What is the most abundant atom in the human body?

Answer 37

Hydrogen

Question 38

Precessional frequency is measured in Tesla.

Answer 38

False

Question 39

The Larmor Equation is given by:

Answer 39

ω₀ = B₀ × γ

Question 40

What does the term "alignment" refer to in MRI?

Answer 40

The orientation of magnetic moments relative to Bo

Question 41

The external magnetic field (B₀) causes nuclei to align either:

Answer 41

Parallel of antiparallel

Question 42

What is the longitudinal plane in MRI?

Answer 42

Axis parallel to Bo

Question 43

The most commonly used isotope in MRI is ___________.

Answer 43

Protium

Question 44

Which of the following nuclei is NOT MR active?

Answer 44

Helium-4

Question 45

The process of returning to thermal equilibrium is known as ___________.

Answer 45

Relaxation

Question 46

NMV

Answer 46

Net Magnetic Vector

Question 47

TR

Answer 47

repetition time