RT 309 MRI Midterm: Basic Nomenclatures and Terms in MRI

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Questions and Answers

What term is used to describe the property of atoms with an odd number of protons in their nuclei exhibiting magnetic resonance?

Magnetic resonance

Why are hydrogen nuclei ideal for MRI?

Hydrogen nuclei have a large magnetic moment and behave like tiny bar magnets.

What is net magnetization in the context of MRI?

Net magnetization is achieved when a fraction of proton dipoles align with the static magnetic field.

Define precession in the context of MRI.

Precession is the phenomenon of the magnetic field spinning or gyrating around an imaginary axis. Signup and view all the answers

What is spin density and how is it related to MRI signal strength?

Spin density is the concentration of hydrogen nuclei in tissue, and signal strength is proportional to the number of nuclei. Signup and view all the answers

What does magnetic moment refer to in the context of MRI?

Magnetic moment refers to the spinning motion of positive protons and negative electrons in the atom. Signup and view all the answers

What is the term for the large-scale macroscopic magnetic moment resulting from many nuclear magnetic moments?

Magnetization Signup and view all the answers

What is the term for the signal emitted by tissue after RF excitation?

Free Induction Decay (FID) Signup and view all the answers

What is the term for the amount of magnetic flux in a unit area perpendicular to the direction of magnetic flow?

Magnetic Intensity Signup and view all the answers

What is the fundamental equation for MRI that relates static magnetic field strength (B0) to precessional frequency using the gyromagnetic ratio?

Larmor Equation Signup and view all the answers

What is the term for the frequency at which a nucleus precesses in the magnetic field?

Larmor Frequency Signup and view all the answers

What happens to the protons when RF stops after RF excitation in MRI?

They align with the applied magnetic field and attain the normal rate of precession Signup and view all the answers