The 2 types of enhancement media described by Lauffer, the mechanism of T1 agents is -
ANSWER to decrease T1 relaxation time, thus emitting high signal
An analogy for the decoding of the MR signal through Fourier Transform - ANSWER
Basilar membrane processing sound
Logically each line of phase encoding data is combined to allow the FT to determine the
position along the y-axis. The number of phase encoding steps determines - ANSWER the
number of pixels along the y-axis
In a gradient echo pulse sequence, which flip angle will produce a T2 weighted gradient echo
image. - ANSWER >20 - <45 degree flip angle
In a horizontal magnet, what is the primary Gs (slice select gradient) for an axial slice -
ANSWER Gz (axial slice)
A linear relationship between frequency and position is superimposed on Bo by the Gp
(phase encoding gradient). The Hydrogen protons relative precessional frequencies
determine - ANSWER phase shifts
Combining a metal ion with a ligand reduces their tendency to bind to proteins, enzymes, or
membranes. The degree to which they dissociate is a measure of their - ANSWER toxicity
In a phase sequence employing 2DFT, the time can be calculated using which formula -
ANSWER TR x NEX x Matrix
What pulse imaging technique is in all implementations of MRA - ANSWER gradient echo
1
,What year was the first MRI enhancement agent approved for clinical use - ANSWER
1988
Increasing NEX - ANSWER Increase SNR and Resolution
Inversion time, in an IR pulse sequence, is the time interval between the - ANSWER 180
degree and 90 degree pulses
Increasing the matrix - ANSWER increase resolution
A pulse sequence that replaces the second RF pulse with a gradient magnetic field to
rephase the transverse vector and produce and echo is called - ANSWER gradient echo
Increase FOV, TE, Slice thickness does - ANSWER not affect scan time
In spatial localization which factor most affects slice thickness and position - ANSWER
bandwidth and strength of Gs (slice select gradient)
The two types of enhancement media described by Lauffer, the mechanism of T2 agents is -
ANSWER to decrease T2 relaxation time, thus emiting a high signal
A generation of phase differences along a particular direction of a slice - ANSWER phase
encoding
Who described the mathematical method of converting a time-varying signal into its
frequency components which are used to obtain positional information from the MR signal -
ANSWER Jean Baptiste - Joseph Fourier
2
, A generation of frequency differences along a particular direction of a slice is called -
ANSWER frequency encoding
In a horizontal field magnet what is the primary Gs (slice select gradient) for a sagittal slice -
ANSWER Gx (sagittal slice)
Pixel size formula - ANSWER FOV/Matrix
In an IR pulse sequence what will produce a STIR fat suppressed pulse sequence -
ANSWER IR of 80 - 120ms
Decrease slice thickness - ANSWER decreases SNR
When selecting a volume of slices, which method for providing spatial encoding is employed
- ANSWER 3DFT
The purpose of the first use of metal ions in MRI enhancement like Gadolinium is to -
ANSWER Decrease relaxation time for Hydrogen in the tissue
Which type of MRI magnet is made up of naturally ferromagnetic material - ANSWER
superconductive magnet
Which type of receiver RF coil is placed close to the patients body for the purpose of
superficial anatomic structures - ANSWER surface coils
The tissue characteristic that provides more tissue contrast and and pathology information is
- ANSWER T2 effects
The longitudinal component of the NMV is designated as - ANSWER Mz
3
ANSWER to decrease T1 relaxation time, thus emitting high signal
An analogy for the decoding of the MR signal through Fourier Transform - ANSWER
Basilar membrane processing sound
Logically each line of phase encoding data is combined to allow the FT to determine the
position along the y-axis. The number of phase encoding steps determines - ANSWER the
number of pixels along the y-axis
In a gradient echo pulse sequence, which flip angle will produce a T2 weighted gradient echo
image. - ANSWER >20 - <45 degree flip angle
In a horizontal magnet, what is the primary Gs (slice select gradient) for an axial slice -
ANSWER Gz (axial slice)
A linear relationship between frequency and position is superimposed on Bo by the Gp
(phase encoding gradient). The Hydrogen protons relative precessional frequencies
determine - ANSWER phase shifts
Combining a metal ion with a ligand reduces their tendency to bind to proteins, enzymes, or
membranes. The degree to which they dissociate is a measure of their - ANSWER toxicity
In a phase sequence employing 2DFT, the time can be calculated using which formula -
ANSWER TR x NEX x Matrix
What pulse imaging technique is in all implementations of MRA - ANSWER gradient echo
1
,What year was the first MRI enhancement agent approved for clinical use - ANSWER
1988
Increasing NEX - ANSWER Increase SNR and Resolution
Inversion time, in an IR pulse sequence, is the time interval between the - ANSWER 180
degree and 90 degree pulses
Increasing the matrix - ANSWER increase resolution
A pulse sequence that replaces the second RF pulse with a gradient magnetic field to
rephase the transverse vector and produce and echo is called - ANSWER gradient echo
Increase FOV, TE, Slice thickness does - ANSWER not affect scan time
In spatial localization which factor most affects slice thickness and position - ANSWER
bandwidth and strength of Gs (slice select gradient)
The two types of enhancement media described by Lauffer, the mechanism of T2 agents is -
ANSWER to decrease T2 relaxation time, thus emiting a high signal
A generation of phase differences along a particular direction of a slice - ANSWER phase
encoding
Who described the mathematical method of converting a time-varying signal into its
frequency components which are used to obtain positional information from the MR signal -
ANSWER Jean Baptiste - Joseph Fourier
2
, A generation of frequency differences along a particular direction of a slice is called -
ANSWER frequency encoding
In a horizontal field magnet what is the primary Gs (slice select gradient) for a sagittal slice -
ANSWER Gx (sagittal slice)
Pixel size formula - ANSWER FOV/Matrix
In an IR pulse sequence what will produce a STIR fat suppressed pulse sequence -
ANSWER IR of 80 - 120ms
Decrease slice thickness - ANSWER decreases SNR
When selecting a volume of slices, which method for providing spatial encoding is employed
- ANSWER 3DFT
The purpose of the first use of metal ions in MRI enhancement like Gadolinium is to -
ANSWER Decrease relaxation time for Hydrogen in the tissue
Which type of MRI magnet is made up of naturally ferromagnetic material - ANSWER
superconductive magnet
Which type of receiver RF coil is placed close to the patients body for the purpose of
superficial anatomic structures - ANSWER surface coils
The tissue characteristic that provides more tissue contrast and and pathology information is
- ANSWER T2 effects
The longitudinal component of the NMV is designated as - ANSWER Mz
3
