MRI lecture
Flashcard 1
Q: What is radiation?
A: The transfer of energy in the form of particles or waves
Flashcard 2
Q: What forms of energy are used in diagnostic imaging?
A: Different forms of radiation are used in diagnostic imaging
Flashcard 3
Q: What types of radiation are the same in nature but differ in energy?
A: Radiation from radios, visible light, and x-rays.
Flashcard 4
Q: Who is one of the inventors of MRI?
A: Dr. Raymond Damadian.
Flashcard 5
Q: What does the MRI magnet create?
A: The primary magnetic field.
Flashcard 6
Q: How strong is 1 Tesla?
A: 10,000 gauss.
Flashcard 7
Q: MRI magnets are what type of magnets?
A: Electromagnets.
Flashcard 8
Q: What is needed to create a powerful magnetic field in MRI?
A: A high amount of current.
Flashcard 9
Q: What happens when high current runs through a wire?
A: A magnetic field is created.
Flashcard 10
Q: What surrounds MRI superconducting magnets?
A: A cooling system (e.g. liquid helium at -453°F).
Flashcard 11
Q: Why does superconductivity matter in MRI?
A: No electrical resistance means current flows indefinitely, maintaining the magnetic field.
Flashcard 12
Q: What is the most abundant substance in the body and important for MRI?
A: Water (about 70%).
Flashcard 13
Q: What part of the water molecule does MRI primarily interact with?
A: Hydrogen nuclei (protons).
Flashcard 14
Q: What generates a magnetic field in an atom?
A: Moving charged particles like electrons and protons.
Flashcard 15
Q: What happens to hydrogen protons in an MRI magnetic field?
A: Some align with and others against the magnetic field.
Flashcard 16
Q: What induces the human body to emit signals in MRI imaging?
A: Radiofrequency (RF) pulses.
Flashcard 17
Q: What do the RF coils in MRI do?
A: Send and receive radio waves from hydrogen nuclei.
Flashcard 18
Q: What is the Larmor Frequency?
A: The resonant frequency at which hydrogen nuclei absorb energy in a magnetic field.
Flashcard 19
Q: What is the principle behind MRI's "resonance"?
A: Every molecule or particle has a resonant frequency to which they are tuned
Flashcard 20
Q: What do gradient coils do in an MRI machine?
A: Alter the main magnetic field to localize signals.
Flashcard 21
Q: Does an emergency shutdown of an MRI system turn off the magnet?
A: No, the magnetic field remains active.
Flashcard 22
Q: What is a "quench" in MRI?
A: A rapid loss of superconductivity and magnetic field, boiling off liquid helium.
Flashcard 23
Q: What are the effects of quenching an MRI magnet?
A: Magnetic field collapses in <3 minutes; 24-72 hours downtime. Cryogen rapidly boil-off
Flashcard 24
Q: In life-threatening situations, what MRI procedure may be used?
A: Quenching the magnet.
Flashcard 25
Q: What phrase is used to emphasize magnet importance in MRI safety?
A: "Bet on the Magnet!"
Flashcard 26
Q: What are MRI safety zones?
A: Designated areas with specific safety protocols around the MRI machine.
Flashcard 27
Q: Name some applications of MRI.
A: (Open-ended: Can include brain scans, joint imaging, cardiovascular studies, etc.)
Flashcard 28
Q: Electromagnetic Radiation
A: The radiation associated with radios, visible light, and x-rays are the same, just with different amounts of energy
Flashcard 29
Q: How strong is the MRI magnet
A: 60,000x the earth’s magnetic field
Flashcard 30
Q: Any charged particle which is moving generates a ________________ field along with its electrical field.
A: Magnetic
Flashcard 31
Q: Protons are spinning charged particles, When they realign with the magnetic field, it creates a _____________ (EMR) in the form of a radio wave
A: oscillating disturbance
Flashcard 32
Q: What happens when the radio waves are then turned off?
A: The hydrogen protons return to their alignment with the magnetic field
Flashcard 33
Q: electro-magnetic coils used to _____________ the main magnetic field
A: alter