FREE MRSO Static Magnetic Field (B0) Bioeffects and Exposure Limits Questions and Answers

Question 1

What is the primary bioeffect associated with the magneto-hydrodynamic effect caused by the static magnetic field (B0)?

Accepted Answer

An increase in T-wave amplitude on an ECG

Answer

Peripheral nerve stimulation

Answer

Auditory damage from acoustic noise

Answer

Tissue heating due to RF absorption

Question 2

According to the U.S. Food and Drug Administration (FDA), what is the static magnetic field (B0) limit for clinical imaging of adults, children, and infants older than one month?

Accepted Answer

8.0 Tesla

Answer

1.5 Tesla

Answer

3.0 Tesla

Answer

4.0 Tesla

Question 3

The translational force on a ferromagnetic object is greatest where the...

Accepted Answer

spatial gradient of the magnetic field is maximal.

Answer

static magnetic field (B0) is highest.

Answer

radiofrequency (RF) field is most uniform.

Answer

time-varying gradient fields are switched fastest.

Question 4

What is the primary physiological mechanism responsible for the sensations of vertigo, dizziness, or nystagmus when moving within a strong static magnetic field?

Accepted Answer

Interaction with the vestibular system's endolymph.

Answer

Stimulation of the auditory nerve by Lorentz forces.

Answer

Induced currents in the cerebral cortex.

Answer

Temporary reduction in cerebral blood flow.

Question 5

The International Commission on Non-Ionizing Radiation Protection (ICNIRP) guidelines for occupational exposure to static magnetic fields recommend a time-weighted average (TWA) exposure limit over an 8-hour workday of:

Accepted Answer

200 mT

Answer

50 mT

Answer

100 mT

Answer

500 mT

Question 6

During a magnet quench, the rapid boil-off of liquid helium poses several immediate hazards. Which of the following is the MOST critical and immediate life-threatening hazard inside the magnet room?

Accepted Answer

Asphyxiation due to oxygen displacement

Answer

The loud noise of the event

Answer

Frostbite from contact with cold gas

Answer

Projectile risk as the field collapses