MRI: Signal Source

Question 1

Consider a proton or hydrogen (1H) nucleus.

Spin will give this nucleus two vector quantities, Φ and µ

µ refers to

Answer 1

Magnetic moment

Question 2

Consider a proton or hydrogen (1H) nucleus.

Spin will give this nucleus two vector quantities, Φ and µ

Φ refers to

Answer 2

Spin angular momentum

Question 3

A purely quantum mechanical quantity with no direct classical analogue

Answer 3

Spin

Question 4

Concerned about the charge and angular momentum of the nuclei atoms, but not with radioactivity

Answer 4

Nuclear magnetic resonance (NMR)

Question 5

A nucleus with either of these two characteristics has an angular momentum (phi) called “spin”

Answer 5

Odd atomic number or odd mass number

Question 6

MR signals are generated by manipulating this magnetic moment (µ) through _____

This is also analogous to electromagnetic induction from a bar magnet

Answer 6

Magnetic resonance

Question 7

90% of anatomical MRI is 1H.

This is because it is also

Answer 7

Naturally abundant (humans are 70% water and water molecule consists of 2H and one O atom)

Question 8

90% of anatomical MRI is 1H.

This is because a hydrogen nucleus consisting of a single proton can be considered a

Answer 8

Simple magnet

Question 9

These nuclei of these alternative protons are also important in MRI

Answer 9

1 H, 13C, 19F, 23Na, and 31P

Question 10

Most anatomical MRI is about

Answer 10

1H

Question 11

Often γ / 2pi (MHz/Tesla) is used instead

γ or the proportionality constant is known as the

Answer 11

Gyromagnetic ratio (10^6 radians/sec/Tesla for proton)

Question 12

Φ and µ are related through a

Answer 12

Proportionality constant (γ)