Week 5 Quiz Flashcards
The MR signal is produced by magnetization _________________.
Select one:
a. in the longitudinal direction
b. decaying
c. in the transverse plane
d. out of phase
in the transverse plane
What is the normal range of lab values for creatinine:
A. 0.6-1.2 mg/dL
B. 7-20 mg/dL
C. >60 mL/min
D. <60mL/min
0.6-1.2 mg/dL
ACR guidelines recommend a 4-zone system for MR suites. Zone 1 is best describe with which description.?
Select one:
A. Area has restricted access and contains the MR scanner, anyone who enters this Zone must be directly supervised by trained MR personnel.
B. Area is freely accessible to the public, contains areas such as the reception desk and lobby.
C. Area is the buffer between freely accessible and restricted zones, this is the Zone where screening occurs and contains areas such as dressing rooms.
D. Area has restricted access and contains the scanner control room, only screened individuals are allowed into this area.
Area is freely accessible to the public, contains areas such as the reception desk and lobby
There are a total of ___ tarsal bones.
a. 4
b. 5
c. 7
d. 8
7
If a phase resolution of 256 is desired, then the TR must be repeated ___________ times (for 1 NSA).
Select one:
a. 256
b. 512
c. twice
d. 192
256
The gradient magnetic fields are:
Select one:
a. controlled by RF pulses
b. always on
c. used for contrast control
d. superimposed over the main magnetic field
superimposed over the main magnetic field
In a gradient echo sequence, reducing the flip angle while holding the TR constant reduces ______________.
Select one:
a. T2* contrast weighting
b. spin density contrast weighting
c. saturation
d. scan time
e. all of the above
saturation
Which sequence of RF pulses accurately depicts a CSE sequence?
Select one:
a. 90 - 180 - 90
b.180 - 90 - 180
c. 90 - 90 - 90
d. 90 - 45 - 45
90-180-90
Fourier transform will be applied to:
Select one:
a. free induction decay
b. RF signal
c. post-processed image data
d. data in k-space
data in k-space
What parameter affects voxel volume?
Select one:
a. slice thickness
b. TI
c. FID
d. TR
slice thickness
A gradient echo pulse sequence uses a _________________ to produce the echo.
Select one:
a. gradient magnetic field
b. ionizing radiation pulse
c. acoustic resonance trigger
d. electrical switching device
gradient magnetic field
The individual hydrogen protons aligned in the parallel direction, in excess of the number aligned in the antiparallel direction, produce a _____________ vector parallel to the main magnetic field.
Select one:
a. net magnetization
b. varying
c. rotating
d. oscillating
net magnetization
The B1 magnetic field is oriented _______________ to the static magnetic field.
Select one:
a. perpendicular
b. parallel
c. 180 degrees
d. at a 45-degree angle
perpendicular
ACR guidelines recommend a 4-zone system for MR suites. Zone 3 is best describe with which description.?
Select one:
A. Area has restricted access and contains the MR scanner, anyone who enters this Zone must be directly supervised by trained MR personnel
B. Area is freely accessible to the public, contains areas such as the reception desk and lobby
C. Area is the buffer between freely accessible and restricted zones, this is the Zone where screening occurs and contains areas such as dressing rooms
D. Area has restricted access and contains the scanner control room, only screened individuals are allowed into this are
Area has restricted access and contains the scanner control room, only screened individuals are allowed into this area.
_____________ describes the condition reached within a few seconds of hydrogen being placed in a magnetic field.
Select one:
a. FID
b. Equilibrium
c. Resonance
d. Phase coherence
Equilibrium
SNR is a ratio of MR signal to ___________.
Select one:
a. noise
b. TR
c. scan time
d. TE
noise
Aliasing is another name for:
Select one:
a. fold over
b. wrap around
c. ghosting
d. a & b
e. all of these
A & B
Aliasing occurs when:
Select one:
a. the FOV is too large
b. the FOV is too small
c. the slice thickness is greater than 3mm
d. when gating is not used
the FOV is too small
The hydrogen proton has been used for MR imaging because:
Select one:
a. it is the most abundant element in the body
b. it possesses a magnetic moment
c. it precesses at a frequency which is in a safe range with currently available magnets
d. all of these
All of these
Precession refers to:
Select one:
a. the frequency of the RF pulse used to excite the proton
b. the orientation of the imaging plane within the magnetic field
c. the “wobble” of the axis of the proton as it spins in the magnetic field
d. the process by which the proton loses energy after excitation by the RF pulse
the “wobble” of the axis of the proton as it spins in the magnetic field
Which of the following RF flip angles maximizes the amount of transverse magnetization?
Select one:
a. 45°
b. 120°
c. 180°
d. 90°
90 degree
Which of the following is not a requirement for magnetic resonance imaging?
Select one:
a. a strong magnetic field
b. RF energy
c. atomic nuclei with unpaired nucleons
d. ionizing radiation
ionizing radiation
With conventional spin echo a single “line” of k-space is filled during each ________________.
Select one:
a.TR
b. excitation
c. TE
d. frequency encoding
TR
The formula that describes the relationship between the static magnetic field and the precessional frequency of the hydrogen protons is the ___________.
Select one:
a. Helmholtz relationship
b. Bloch equation
c. Larmor equation
d. Nyquist theorem
Larmor equation
The RF energy used in MRI is classified as _______________.
Select one:
a. a magnetic beam
b. investigational waveform
c. electromagnetic radiation
d. non-radiation energy
electromagnetic radiation
If the TR of a gradient echo sequence is less than the T1 and T2 time of tissue, a condition known as ______________ will be achieved.
Select one:
a. echo readout
b. steady state
c. spin dephasing
d. spin saturation
steady state
Which of the following parameters affects image contrast?
Select one:
a. Matrix size
b. FOV
c. NEX
d. TR
TR
To calculate the precessional frequency, the strength of the static magnetic field is multiplied by a constant known as ______________.
Select one:
a. the gyromagnetic ratio
b. linear attenuation coefficient
c. alpha-1
d. tau
the gyromagnetic ratio
If a phase resolution of _______ is desired, then the TR must be repeated 512 times (for 1 NSA).
Select one:
a. twice
b. 256
c. 512
d. 192
512
The U.S. Food and Drug Administration recommends that patients not be subjected to sound levels greater that _____ dB without hearing protection.
a. 50
b. 85
c. 99
d. 130
99
If a patient has a history of metal shavings in their eye(s), the accepted standard for screening is _______________.
Select one:
a. CT scan
b. nothing, the patient is not to be scanned with MRI
c. physical examination
d. plain film x-ray of the orbits
plain fil x-ray of the orbits
With conventional spin echo a single “line” of k-space is filled during each ________________.
Select one:
a. TR
b. frequency encoding
c. excitation
d. TE
TR
The SAR limit set by the FDA for the head is:
a. 3 W/kg averaged over 10 minutes
b. 4 W/kg averaged over 15 minutes
c. 8 W/kg averaged over 5 minutes
d. 12 W/kg averaged over 5 minutes
3 W/kg averaged over 10 minutes
A magnetic field strength of 1 Tesla is equivalent to ____________ Gauss.
Select one:
a. 10,000
b. 1,000
c. 1.0
d. 15,000
10,000
A surface coil wire cannot cause an injury to the patient if it is not frayed.
Select one:
True
False
False
A gradient echo pulse sequence uses a _________________ to produce the echo.
Select one:
a. gradient magnetic field
b. ionizing radiation pulse
c. acoustic resonance trigger
d. electrical switching device
gradient magnetic field
_________ is defined as threatening to harm an individual.
a. Coercion
b. Negligence
c. Assault
d. Battery
Assault
The strength of magnetic fringe fields is measured in:
Select one:
a. Gauss
b. Watts
c. Tesla
d. SAR
Gauss
The static magnetic field strength of MR systems is measured in units of:
Select one:
a. SAR
b. Watts
c. Gauss
d. Tesla
Tesla
Malpractice is defined as:
A. A legal or civil wrong committed by one person against the person or property of another
B. An obligation not to inflict harm intentionally
C. Professional misconduct, improper discharge of professional duties, or a failure to meet the standard of care by a professional that results in harm to another
D. A failure to exercise the appropriate/reasonable level of care expected to be exercised by professionals in a given circumstance
Professional misconduct, improper discharge of professional duties, or a failure to meet the standard of care by a professional that results in harm to another
What is the normal range of lab values for BUN:
A. 0.6-1.2 mg/dL
B. 7-20 mg/dL
C. >60 mL/min
D. <60mL/min
7-20 mg/dL
Cables from ECG leads and RF coils must be:
a. placed straight through the bore of the magnet, not coiled
b. laid into neat loops at the patient’s feet
c. laid along the patient’s right arm, neatly braided
d. no particular placement is required as long as the cables are plugged in
placed straight through the bore of the magnet, not coiled
Gradient magnetic fields are used to ______________.
Select one:
a. control the image contrast
b. spatially encode signal
c. improve the SNR
d. transmit the RF pulse
spatially encode signal
What is the normal range of lab values for eGFR:
A. 0.6-1.2 mg/dL
B. 7-20 mg/dL
C. >60 mL/min
D. <60mL/min
> 60 mL/min
Presaturation pulses are used to ________________.
Select one:
a. turn flowing blood bright
b. reduce scan time
c. improve spatial resolution
d. reduce flow artifacts
reduce flow artifacts
