MRI PHYSICS TEXT BOOK ARRT PRACTICE WITH ALL
CORRECT & 100% VERIFIED ANSWERS|LATEST
VERSION|GUARANTEED TO PASS
when use of an MRI contrast agent causes tissue to appear brighter which of the following has
occurred ? ✔Correct Answer-positive contrast
relaxation centers are regions of ✔Correct Answer-increased magnetizatiom
when exposed to intense static magnetic fields, filtered human cells.. ✔Correct Answer-show no
effect
the main potential for biological response from RF is ✔Correct Answer-tissue heating
electric current density induced by transient magnetic fields is measured in ✔Correct Answer-
ampere per square centimeter
the threshold for induction of magnetic phospjenes at low frequencies is approximately ✔Correct
Answer-3T/s
the human responses reported during imaging with a 4T system are presumed to be due to
✔Correct Answer-transient magnetic fields
bone fracture healing is helped by ✔Correct Answer-low frequency RF
at the start of an MRI exam patient anxiety is generally due to ✔Correct Answer-claustrophobia
approximately what percent of all patients exhibit claustrophobia ✔Correct Answer-5
operation of a successful MRI facility must include ✔Correct Answer-calling each outpatient the
day before the scheduled examination
continuing education of mri technologists is ✔Correct Answer-essential
pulse sequences optimized for imaging the CNS are usually not appropriate for body imaging
because for CNS compared w body tissues ✔Correct Answer-T1 and T2 are long
if a quench occurs and helium escapes, the principle effect on the mri technologist will be
✔Correct Answer-Donald Duck Voice
proper quality control for an mri system requires that test object imaging be performed at least
✔Correct Answer-daily
the principal hazard to patient and personnel in an mri facility is the biological effect of ✔Correct
Answer-ferromagnetic projectiles
a clearly marked exclusion area should be identified at the ✔Correct Answer-0.5-mT fringe field
, after a 90 degree RF pulse the signal received from the patient is ✔Correct Answer-a free induction
decay
the term pulse sequence refers to ✔Correct Answer-gradient magnetic field pulses and RF pulses
the time-to-echo (TE) is the time between the ✔Correct Answer-90 degree RF pulse and spin echo
the inversion recovery pulse sequence consists of a train of ✔Correct Answer-180 ... 90 ... 180 ... 90
which of the following pulse sequences involves all three (TR, TE, TI) ✔Correct Answer-inversion
recovery
as Mxy relaxes to zero ✔Correct Answer-signal intensity decreases
after the relaxation of net magnetization to equilibrium the MR signal ✔Correct Answer-is zero
at equilibrium, if a 90 degree RF pulse is used which of the following ME sognals will be produced
✔Correct Answer-free induction decay
control of TE is excersized by control of ✔Correct Answer-the 180 degree RF pulse
with the inversion recovery pulse sequence MR images are constructed from ✔Correct Answer-
spin echos
in MRI the role of the fourier transform is to ✔Correct Answer-change the MR signal into a
frequency spectrum
The Fourier transformation of a spin echo results in data in the ✔Correct Answer-frequency
domain
the result of a fourier transform in MRI is called an ✔Correct Answer-object function
in MRI smooth objects are represented by ✔Correct Answer-low frequencies
the mathematical tool used to analyze the frequency content of an object is the ✔Correct Answer-
fourier transform
noise in an image is generally more apparent when ______________ is present ✔Correct Answer-
high spatial frequency
the raw data of an MR signal contains what components of the spatial frequency ✔Correct
Answer-magnitude and phase
in general when one samples the data of the spatial frequency domain with emphasis on the higher
spatial frequencies the ✔Correct Answer-signal-to-noise ration will be less
the physiologic motion of a nervous action potential takes approximately how much time
✔Correct Answer-200 ms
when an image is constructed the matrix size is equal to the number of different ✔Correct Answer-
phase-encoding gradients applied
CORRECT & 100% VERIFIED ANSWERS|LATEST
VERSION|GUARANTEED TO PASS
when use of an MRI contrast agent causes tissue to appear brighter which of the following has
occurred ? ✔Correct Answer-positive contrast
relaxation centers are regions of ✔Correct Answer-increased magnetizatiom
when exposed to intense static magnetic fields, filtered human cells.. ✔Correct Answer-show no
effect
the main potential for biological response from RF is ✔Correct Answer-tissue heating
electric current density induced by transient magnetic fields is measured in ✔Correct Answer-
ampere per square centimeter
the threshold for induction of magnetic phospjenes at low frequencies is approximately ✔Correct
Answer-3T/s
the human responses reported during imaging with a 4T system are presumed to be due to
✔Correct Answer-transient magnetic fields
bone fracture healing is helped by ✔Correct Answer-low frequency RF
at the start of an MRI exam patient anxiety is generally due to ✔Correct Answer-claustrophobia
approximately what percent of all patients exhibit claustrophobia ✔Correct Answer-5
operation of a successful MRI facility must include ✔Correct Answer-calling each outpatient the
day before the scheduled examination
continuing education of mri technologists is ✔Correct Answer-essential
pulse sequences optimized for imaging the CNS are usually not appropriate for body imaging
because for CNS compared w body tissues ✔Correct Answer-T1 and T2 are long
if a quench occurs and helium escapes, the principle effect on the mri technologist will be
✔Correct Answer-Donald Duck Voice
proper quality control for an mri system requires that test object imaging be performed at least
✔Correct Answer-daily
the principal hazard to patient and personnel in an mri facility is the biological effect of ✔Correct
Answer-ferromagnetic projectiles
a clearly marked exclusion area should be identified at the ✔Correct Answer-0.5-mT fringe field
, after a 90 degree RF pulse the signal received from the patient is ✔Correct Answer-a free induction
decay
the term pulse sequence refers to ✔Correct Answer-gradient magnetic field pulses and RF pulses
the time-to-echo (TE) is the time between the ✔Correct Answer-90 degree RF pulse and spin echo
the inversion recovery pulse sequence consists of a train of ✔Correct Answer-180 ... 90 ... 180 ... 90
which of the following pulse sequences involves all three (TR, TE, TI) ✔Correct Answer-inversion
recovery
as Mxy relaxes to zero ✔Correct Answer-signal intensity decreases
after the relaxation of net magnetization to equilibrium the MR signal ✔Correct Answer-is zero
at equilibrium, if a 90 degree RF pulse is used which of the following ME sognals will be produced
✔Correct Answer-free induction decay
control of TE is excersized by control of ✔Correct Answer-the 180 degree RF pulse
with the inversion recovery pulse sequence MR images are constructed from ✔Correct Answer-
spin echos
in MRI the role of the fourier transform is to ✔Correct Answer-change the MR signal into a
frequency spectrum
The Fourier transformation of a spin echo results in data in the ✔Correct Answer-frequency
domain
the result of a fourier transform in MRI is called an ✔Correct Answer-object function
in MRI smooth objects are represented by ✔Correct Answer-low frequencies
the mathematical tool used to analyze the frequency content of an object is the ✔Correct Answer-
fourier transform
noise in an image is generally more apparent when ______________ is present ✔Correct Answer-
high spatial frequency
the raw data of an MR signal contains what components of the spatial frequency ✔Correct
Answer-magnitude and phase
in general when one samples the data of the spatial frequency domain with emphasis on the higher
spatial frequencies the ✔Correct Answer-signal-to-noise ration will be less
the physiologic motion of a nervous action potential takes approximately how much time
✔Correct Answer-200 ms
when an image is constructed the matrix size is equal to the number of different ✔Correct Answer-
phase-encoding gradients applied
