All 12 Modules
The most common type of magnet used in today's MR systems is the _______________.
A. resistive magnet
B. permanent magnet
C. superconducting magnet
D. open MR scanner - Correct Answer C. superconducting magnet
The positively charged part of an atom is the _____________.
A. electron
B. neutron
C. proton
D. nucleus - Correct Answer C. proton
When a hydrogen nucleus is positively charged and spins, it generates a small magnetic field called a
_____________.
A. larmor equation
B. decay moment
C. proton moment
D. magnetic moment - Correct Answer D. magnetic moment
When placed in an external magnetic field, low-energy hydrogen nuclei (protons) point in the
____________ direction.
A. parallel
B. perpendicular
C. antiparallel
D. random - Correct Answer A. parallel
,Which of the following is used to describe the relationship between the static magnetic field and the
precessional frequency of the hydrogen protons?
A. concept of precessing
B. larmor equation
C. theory of magnetism
D. MR equation - Correct Answer B. larmor equation
What term describes hydrogen protons, nuclei rotating in unison?
A. out-of-phase precession
B. in-phase precession
C. magnetic moment
D. nucleus of atoms - Correct Answer B. in-phase precession
This process of applying RF energy to the patient in order to receive a signal from the protons in the
body part being imaged is known as ______________.
A. alignment
B. resonance
C. precession
D. gyromagnetic ratio - Correct Answer B. resonance
Superconductive MR scanners that use cryogen gases have what kind of fields?
A. vertical
B. longitudinal
C. horizontal
D. transverse - Correct Answer C. horizontal
Which coil is located closes to the patient?
,A. magnet
B. gradient
C. shim
D. radiofrequency - Correct Answer D. radiofrequency
When exposed to the magnetic field, a ___________ substance demonstrates a negative magnetic
susceptibility, which means it is repelled by the magnetic field.
A. ferromagnetic
B. paramagnetic
C. superparamagnetic
D. diamagnetic - Correct Answer D. diamagnetic
Which of the following is a characteristic of ultra-high field magnets?
A. signal-to-noise ratios are high and faster imaging times are possible.
B. the scanner has an open design and large gantry aperture
C. magnetic fringe fields are relatively small
D. scanners are light and portable - Correct Answer A. signal to noise ratios are high and faster
imaging times are possible
Which type of magnet varies in field strength from 0.5 to 1.4 tesla (T)?
A. ultra-high field
B. high field
C. midfield
D. low field - Correct Answer C. midfield
Which of the following is an appropriate use of low-field magnets?
A. orthopedic studies
, B. chemical saturation imaging
C. neurovascular studies
D. intraoperative imaging - Correct Answer A. orthopedic studies
Which is the most common electromagnet configuration?
A. permanent
B. resistive
C. superconducting
D. niche - Correct Answer C. superconducting
Which of the following is a disadvantage of superconducting magnets?
A. high operational costs
B. low field strength
C. expensive to purchase
D. vertical magnetic field - Correct Answer C. expensive to purchase
The magnet must be shimmed before imaging sequences to:
A. match the precessional frequency of hydrogen
B. increase the strength of the radiofrequency pulse
C. create a uniform magnetic field
D. decrease the fringe field - Correct Answer C. create a uniform magnetic field
The location of an electron excited by magnetic fields and radiofrequency pulses can be determined
using ____________ and an x, y, z, coordinate system.
A. x-rays
B. waveforms
C. gradients