COMPREHENSIVE QUESTION–ANSWER
DIGEST
◉ in a large main magnetic field such as those employed in MRI, the
motion of a hydrogen proton has been described as wobbling like a
spinning top. this motion is called
A) precession
B) resonance
C) frequency
D) angular momentum.
Answer: precession
◉ magnetic resonance imaging is derived from the process known
as:
A) magnetic resonance angiography
B) magnetic relaxation imaging
C) nuclear magnetic resonance
D) nuclear resonance imaging.
Answer: nuclear magnetic resonance
,◉ Once the nmv has moved away from equilibrium, the following
will occur
A) the longitudinal component will increase
B) the transverse component will decrease
C) the longitudinal component will stay the same
D) the transverse component will increase.
Answer: the transverse component will increase
◉ In MR, substances respond to a specific radio frequency which is
known as:
A) magnetic frequency
B) radio frequency
C) gyro-magnetic frequency
D) resonance frequency.
Answer: resonance frequency
◉ the introduction of gadolinium based contrast enhancement
agents by intra-venous injection can involve passing through an
abnormal blood brain barrier. the tissue compartments involved are
the:
A) intravascular to interstitial
B) extracellular to intracellular
C) hepatobiliary to renal
,D) extradural to renal.
Answer: intravascular to interstitial
◉ t2 is the measurement of time fot the transverse component of the
NMV to decrease what percentage of its maximum value after the
application of a 90 degree radio-frequency pulse
A) 33%
B) 63%
C) 37%
D) 67%.
Answer: 37%
◉ in the USA, the MRI system's magnetic field and vector that
represents it is symbolized:
A) B1
B) B2
C) B3
D) B0.
Answer: B0
◉ The resonance frequency of any substance in a magnetic field can
be calculated by employing the
A) damadian equation
, B) larmor equation
C) faraday equation
D) lauterbur equation.
Answer: Larmor equation
◉ in a pulse sequence, transmitting an initial 90 degree radio-
frequency pulse will cause the NMV to:
A) remain at equilibrium
B) shift in both size and direction
C) move to antiparallel
D) rephase.
Answer: shift in both size and direction
◉ Which type of electromagnetic coils are designed to stimulate and
detect an MR signal?
A) gradient coils
B) radio-frequency coils
C) shim coils.
Answer: radio-frequency
◉ tissues that are less efficient at spin-spin interactions because
they contain more free water, such as CSF, should have