A) hypointense
B) hyperintense
C) isointense
D) isodense - ANSWER isointense
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
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,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
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,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
A) High T2 values and produce hypointense signals
B) HIgh T2 values and produce hyperintense signals
C) low T2 values and produce hypointnese signals
D) low T2 values and produce hyperintense signal - ANSWER High T2 values and produce
hyperintense signals
magnetism can be defined as the ability of certain substances to attract:
A) Copper, aluminum, tin
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, B) Iron, cobalt, nickel
C) Bronze, niobium, titanium
D) Neodymium, niobium-titanium, lodestone - ANSWER Iron, cobalt, nickel
the purpose of magnetic resonance angiography is to image the:
A) stationary soft tissue
B) blood flow
C) vessel lumen
D) only abnormal vessels - ANSWER blood flow
the strength of very large magnetic fields like those employed in MRI systems, the SI unit
most commonly used is:
A) Tesla
B) Gauss
C) Kilogauss
D) militesla - ANSWER Tesla
the larmor frequency of hydrogen protons in a 1.5 tesla magnetic field is:
A) 6.4 MHZ/Tesla
B) 12.8 MHz/Tesla
C) 25.5 MHz/tesla
D) 63.9 MHz/tesla - ANSWER 63.9 MHz/Tesla
In MR imaging, for chemical substance to be affected by the main magnetic field and the
radio-wave it must contain an:
A) Odd number of electrons
B) Odd number of total protons and neutrons
C) Even number of total electrons and neutrons
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