SOLUTION COLLECTION
◉ for MRI magnets, the specification for field homogeneity that is
considered acceptable is:
A) 5-10ppm
B) 10-15ppm
C) 20-30ppm
D) 40-50ppm.
Answer: 20-30ppm
◉ the primary factor of an inversion recovery pulse sequence is
which of the following parameters?
A) TR
B) TE
C) TI
D) FSE
E) MRA.
Answer: TI
◉ of the different types of coils used in MRI, which type(s) are found
only in the housing of the main magnet?
,A) surface coils
B) radio frequency coils
C) Heimholtz coils
D) shim/gradient coils
E) all.
Answer: shim/gradient coils
◉ which of the following causes of artifacts on MR images is most
commonly mistaken for a pathological signal?
A) eddy currents
B) magnetic susceptibility
C) chemical shift
D) untuned RF coils
E) ferromagnetic object.
Answer: chemical shift
◉ of the following anatomical structures, which is considered to be
normally enhancing post gadolinium injection?
A) cerebellum
B) choroid plexus
C) intervertebral disc
D) auditory nerves
,E) corpus callosum.
Answer: choroid plexus
◉ cryogen levels should never fall below:
A) 23%
B) 30%
C) 50%
D) 66%
E) 80%.
Answer: 50%
◉ the electromagnetic coil responsible for producing the strong
magnetic field of a superconducting magnet is embedded in a
_____________ which serves as an insulator from heat in the even of a
quench.
A) niobium-titanium matrix
B) lead matrix
C) carbon composite matrix
D) steel matrix
E) copper matrix.
Answer: copper matrix
, ◉ there are ____________ of _____________ serving the purpose of
providing spatial information within the MR signal
A) 3 pairs/ gradient coils
B) 2 pairs/ shim coils
C) 2 pairs/ RF amplifiers
D) 6 pairs/ solenoid coils.
Answer: 3 pairs/ gradient coils
◉ the temperature of the liquid helium in which the electromagnetic
coil is immersed is appoximately:
A) 32 degree F
B) 0 degree k
C) -40 degree C
D) -436 degree F
E) -4 degree C.
Answer: -436 degree F
◉ cooling the electromagnetic coil windings to the point of
supeconductivity and then inducing an electric current from an
external power supply until the magnet is a full power is called:
A) ramping up
B) resistance load
C) quench