How do magnetic flux lines travel?
A. North to South
B. South to North
C. East to West
D. West to East - ANSWER-A North to South
Which of the following can be potential safety concerns to a patient in
the static magnetic field?
A. Electrically conductive materials
B. Ferrous objects
C. Magnetic objects
D. All of the choices. - ANSWER-D. All of the choices
An object that retains its magnetic field when exiting the static
magnetic field is call what?
A. Paramagnetic
B. Diamagnetic
C. Ferromagnetic
D. Superparamagnetic - ANSWER-C. Ferromagnetic
What direction is the vector of a permanent MR unit?
A. Horizontal
B. Vertical
,C. Diagonal
D. Variable - ANSWER-B. Vertical
What separates a superconducting MR unit from a resistive MR unit?
A. Cryogen
B. Coils of wires
C. Permanent magnets
D. none of the choices - ANSWER-A. Cryogen
The increasing strength of magnetism as we move closer to the MR
unit is called what?
A. Ferromagnetism
B. Spatial magnetic gradient field
C. Vector
D. B0 - ANSWER-B. Spatial magnetic gradient field
What is responsible for attracting ferrous objects into the MR unit?
A. Spatial magnetic gradient fields
B. Strong uniform magnetic fields
C. Gradient coils
D. Radiofrequency system - ANSWER-A. Spatial magnetic gradient
fields
If we placed a small ferrous object at isocenter, what would we expect
to happen?
A. The object would experience no attraction.
B. The object would immediately be attracted to the bore.
,C. The object would levitate.
D. The object would be repulsed by the unit. - ANSWER-A. The object
would experience no attraction.
Rotational force will be the strongest at what location?
A. Isocenter
B. Outside the MR room
C. At the gantry opening
D. At the 5 gauss line - ANSWER-A. Isocenter
Passive shielding uses which of the following?
A. Coils of wires with electrical current running through them.
B. Magnetically conductive materials
C. Plastic
D. Wood - ANSWER-B. Magnetically conductive materials
How can we reduce risks associated with Lenz's force? A.
No risks are associated with Lenz's force.
B. Use a cold compress to reduce heating.
C. Move as quickly as possible to get the patient out of the scanner
quickly.
D. Advance patient into the scanner slowly. - ANSWER-D. Advance
Patient into the scanner slowly.
An implant has a deflection of 23 degrees. In terms of static magnetic
fields, is it safe for this patient to have an MRI?
A. Yes
, B. Must call the manufacture to determine conditions.
C. No
D. Not enough information. - ANSWER-A. Yes
Which of the following stainless steels are non-ferrous?
A. Ferritic
B. Martensitic
C. Austenitic
D. All are ferrous - ANSWER-C. Austenitic
It is not safe for a patient to cross over the 5 gauss line. How many
millitesla is this?
A. 0.5mT
B. 5mT
C. 50mT
D. 0.005mT - ANSWER-A. 0.5mT
A patient is placed in a magnetic field that changes over a distance
from the MR unit. What do we need in order to meet the manufacture
limits if a patient with an implant will be safe from the threats
associated with the static magnetic field prior to their MRI. A. Spatial
gradient map.
B. Compression
C. The MRSO sole approval.
D. All of the choices. - ANSWER-A. Spatial gradient map
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