MRI magnet basics, T1 versus T2 weighting, and MRI safety screening concepts tested on radiologic technology certification exams.
34 cards · basic cards · AI-written, checked twice. Edit anything.
- What does the acronym MRI stand for?
- Magnetic Resonance Imaging
- What unit measures magnetic field strength in MRI?
- Tesla
- 1 Tesla equals how many Gauss?
- 10,000 Gauss
- What type of magnet is used in most clinical MRI scanners?
- Superconducting magnet
- What substance cools the coils of a superconducting MRI magnet?
- Liquid helium
- What is the term for a sudden, uncontrolled loss of superconductivity in an MRI magnet?
- A quench
- Why is a magnet quench dangerous to people in the room?
- Escaping helium gas can displace oxygen and create an asphyxiation risk
- Which atomic nucleus is most commonly imaged in clinical MRI?
- Hydrogen (a single proton)
- What equation relates magnetic field strength to the precession frequency of protons?
- The Larmor equation
- What is the main function of the gradient coils in an MRI system?
- They allow spatial localization of the MR signal
- What is the main function of the RF coils in an MRI system?
- They transmit RF pulses and/or receive the returning MR signal
- In MRI pulse sequences, what does TR stand for?
- Time to repetition, the time between successive RF excitation pulses
- In MRI pulse sequences, what does TE stand for?
- Time to echo, the time between the RF pulse and the signal echo
- A short TR combined with a short TE produces what type of image weighting?
- T1 weighted
- A long TR combined with a long TE produces what type of image weighting?
- T2 weighted