Quiz on Magnetic Resonance Imaging (MRI) Principles

What is the primary target for MRI imaging in the human body?

• Oxygen nuclei (17O)

• Hydrogen nuclei (1H)

• Sodium nuclei (23Na)

• Phosphorous nuclei (31P)

Which of the following statements about hydrogen nuclei in a strong magnetic field is true?

• They become inactive.

• They lose their charge.

• They precess in the direction of the magnetic field.

• They align randomly.

What does the Larmor equation relate to in MRI?

• The duration of the RF pulse.

• The type of tissue being imaged.

• The speed of the MRI machine.

• The strength of the magnetic field and the gyromagnetic ratio.

In a 1.0 Tesla magnetic field, what is the precessional frequency of hydrogen?

• 85.0 MHz

• 21.2 MHz

• 42.6 MHz

• 63.4 MHz

What happens to hydrogen nuclei when an RF pulse is applied?

• They become neutral.

• They flip out of alignment.

• They stop precessing.

• They align with the magnetic field.

What is the effect of transverse relaxation (T2) in MRI?

• The RF pulse is turned off.

• Hydrogen nuclei become inactive.

• Transverse magnetization starts to disappear.

• Longitudinal magnetization increases.

What is the primary function of the RF transmitter in an MRI system?

• To create the magnetic field

• To transmit radiofrequency pulses

• To receive signals from the body

• To control the gradient coils

How do the gradient coils contribute to the functioning of an MRI machine?

• They create the static magnetic field.

• They help in spatial encoding of the signals.

• They generate the radiofrequency pulses.

• They detect the magnetic resonance signals.

How do parallel and anti-parallel hydrogen nuclei affect the net magnetization in MRI?

• They do not interact.

• They enhance the signal.

• They cancel each other out.

• They increase the RF pulse duration.

What is the significance of the gyromagnetic ratio in MRI?

• It determines the strength of the magnetic field.

• It is a constant specific to each nucleus.

• It affects the RF pulse duration.

• It indicates the type of tissue.