Week 3 Quiz Flashcards
Gradient magnetic fields are __________.
Select one:
a. superimposed over the main magnetic field
b. not needed when there is a homogeneous magnetic field
c. generated by shim coils
d. used in place of the main magnetic field
a. superimposed over the main magnetic field
superimposed = in addition to
Patient’s who should be monitored (with pulse oximetry) during MRI procedures are:
A. Unresponsive and uncommunicative patients
B. Sedated, psychiatric, and pediatric patients
C. Patients who have weak voices and/or impaired hearing
Select One:
A. A only
B. A and B only
C. A and C only
D. All of the above
D. All of the above
T1 can be described as:
a. TR 300-1000ms & TE 10-25ms
b. TR 100-1000ms & TE 3-10ms
c. TR 300-1500ms & TE 10-30ms
d. TR 300-1500ms & TE 60-100ms
c. TR 300-1500ms & TE 10-30ms
The 3rd line is called
phase
The 1st line is called
RF pulse
The 2nd line is called
slice
The 4th line is called
frequency
Which type of MRI magnet is made up of naturally ferromagnetic material?
Select One:
A. Superconductive
B. Resistive
C. Permanent
C. Permanent
made from ceramic alloys or other magnetic metals
How many vertebrae are in the vertebral column?
Select One:
A. 31
B. 33
C. 35
D. 37
b. 33
7 cspine (C1-C7)
12 tspine (T1-T12)
5 lspine (L1-L5)
5 sacral vertebrae (S1-S5)
4 coccygeal vertebrae (Co1-Co4)
The conus medullaris is normally located posterior to:
a. L1-L2
b. T11-T12
c. C6-C7
d. L3-L4
a. L1-L2
Gradient magnetic fields are a safety concern because they:
Select One:
A. Produce large amounts of RF energy
B. Induce currents in conductors
C. Cause short-term memory loss
D. All of the above
b. induce currents in conductors
the induced “eddy” currents can cause heating and interfere w/ the MRI system’s performance
To reconstruct an image acquired using parallel imaging, which of the following may be required?
Select One:
A.Half-Fourier acquisition
B. Reference or calibration scan
C. Compatible coil
D. B and C
d. b and c
reference/ calibration scan: allows simultaneous acquisition of multiple lines of k-space
compatible coil: enables faster/more efficient image reconstruction
In an image acquired with a balanced GRE sequence (Figure C.2), all of the following have high (bright) signal EXCEPT:
Select One:
A. Blood in the ventricle
B. CSF
C. IVC
D. Normal myocardium
d. normal myocardium
lower signal = low water content/ more complex tissue structure
MRI contrast injections help to distinguish postoperative scars from recurrent disc herniation by:
a. Enhancing scars on T1-weighted images
b. Enhancing disk on T2-weighted images
c. Enhancing scars on T2-weighted images
d. Enhancing disk on T1-weighted images
a. Enhancing scars on T1-weighted images
As a conductive medium (e.g., Blood) moves across a magnetic field, an effect known as the magnetic hemodynamic effect occurs, resulting in:
Select One:
A. Increased blood pressure
B. Increased temperature
C. Elevated T-Wave
D. No noticeable effect
b. Increased temperature
the movement of blood can induce eddy currents = leading to localized heating
The gradient that is on during the production of the echo is called the:
Select one:
A. Phase encoding gradient
B. Slice select gradient
C. Frequency encoding gradient/Readout gradient
D. Flow encoding gradient
c. Frequency encoding gradient/Readout gradient
this gradient is responsible for encoding the spatial frequency of the signals
Which gradient is applied first in the MRI sequence to select the slice?
Select one:
A. Frequency encoding gradient
B. Phase encoding gradient
C. Slice select gradient
D. Flow encoding gradient
C. Slice select gradient
Which gradient is applied second in the MRI sequence, after the slice select gradient, to encode spatial information in the phase direction?
Select one:
A. Frequency encoding gradient
B. Phase encoding gradient
C. Slice select gradient
D. Flow encoding gradient
B. Phase encoding gradient
Which gradient is applied last in the MRI sequence to encode spatial information in the frequency direction during the readout phase?
Select one:
A. Frequency encoding gradient
B. Phase encoding gradient
C. Slice select gradient
D. Flow encoding gradient
A. Frequency encoding gradient
If a given conventional spin-echo pulse sequence takes 12 minutes to acquire, a fast spin-echo sequence using an ETL of 6, with all other factors that affect scan time remaining the same, will take:
Select one:
A. 2 minutes
B. 1 minute
C. 6 minutes
D. 4 minutes
A. 2 minutes
In an inversion recovery pulse sequence, image contrast is controlled by
Select on:
A. TR and TE only
B. TI only
C. TI and TE only
D. TR, TE, and TI
D. TR, TE, and TI
Gradient moment nulling is most effective when correcting for motion-induced signal loss from
Select one:
A. Pulsatile flow
B. No flow
C. Slow constant flow
D. Magnetic field in inhomogeneities
A. Pulsatile flow
GMN is a technique used to correct for motion-induced signal loss, particularly in cases where the motion is periodic
used in vascular imaging, where blood flow during the cardiac cycle is pulsatile
Which of the following conditions is common in a patient with COPD
Select one:
A. Bradycardia
B. Orthopnea
C. Dysphagia
D. Epistaxis
B. Orthopnea
Tissues with short T1 relaxation times (like fat and gadolinium = enhancing’s structures) a pair ______ as compared to normal structures on T1 weighted images
Select one:
A. Hyperintense/Brighter than
B. Hypointense/Darker than
C. Isointense/the same signal intensity as
D. Dark
A. Hyperintense/Brighter than
tissues with shorter T1 times (like fat and areas w. gadolinium contrast) recover longitudinal magnetization more quickly
The cranial nerves running through the internal auditory canals are -
Select one:
A. IV and V
B. V and VI
C. VI and VII
D. VII and VIII
E. VIII and IX
D. VII and VIII
Transmit gain is a factor that determines the
Select one:
A. Frequency of RF used for excitation
B. Frequency of RF used for signal detection
C. A and B
D. Amplitude and/or duration of the RF pulse (to determine flip angle)
D. Amplitude and/or duration of the RF pulse (to determine flip angle)
this factor directly affects the flip angle of the protons
it determines how much the proton spins are tilted from their longitudinal axis during the RF pulse
As TR increases, partial volume averaging -
Select one:
A. Increases
B. Decreases
C. Stays the same
D. Not effected
A. Increases
