principals quiz 5

Which of the following GRE pulse sequence types use data from only the FID? Incoherent Gradient Echo. Steady State Free Precession. Coherent Gradient Echo.

Incoherent Gradient Echo.

Which is not an advantage of GRE scanning? Decreased magnetic susceptibility artefacts. Shorter scan times. Ability to use breath hold techniques. Decreased flow voids.

Decreased magnetic susceptibility artefacts.

At which point in an MRI pulse sequence diagram would the stimulated echo be present? During the third RF pulse. During the fourth RF pulse. During the second RF pulse. After the first RF pulse.

During the third RF pulse

Which of the following GRE pulse sequence types uses a spoiler pulse? Incoherent. Steady State Free Precession. Coherent. Balanced GRE.

Incoherent.

A gradient echo sequence in which any residual transverse magnetization is removed prior to the next excitation pulse is known as: Magnetization prepared. Nonresidual. Nonphasic. Incoherent/ spoiled.

Incoherent/ spoil

Which of the following statements about incoherent gradient echo pulse sequences is true? Incoherent GRE sequences use only residual transverse magnetization so that signal generation includes all of the steady state magnetization. Incoherent GRE sequences spoil or dephase residual transverse magnetization so that only magnetization from the previous excitation is used.

Incoherent GRE sequences spoil or dephase residual transverse magnetization so that only magnetization from the previous excitation is used.

What type of gradient echo is generated in the following image?

Incoherent Gradient Echo

What type of pulse sequence is depicted in the image?

Incoherent Gradient Echo

Gradient echo sequences can yield either T1 or T2* characteristics. True False

True

Which of the following GRE pulse sequence types uses a rewinding pulse? Balanced. Incoherent. Steady State Free Precession (SSFP). Coherent

(33.33 %) Coherent

Which of the following is a mechanism that incoherent gradient pulses sequences use to dephase leftover transverse magnetization? Gradient Rewinding RF Rewinding Gradient Spoiling RF Spoiling

(50 %) RF Spoiling

What is the general definition of the steady state?

A condition that does not change over time.

Gradient slew rates need to be how many times faster for Single Shot EPI imaging than conventional imaging? 2 times 6 times 4 times 10 times

4 times

Which term describes a spin echo that is produced by two 90 degree flip angle RF pulses? A Hahn echo. A Han Solo echo. A stimulated echo.

A Hahn echo.

A gradient pulse sequence uses which of the following to rephase transverse magnetization? A variable RF pulse. A 180 degree excitation pulse. A 90 degree excitation pulse. A gradient pulse

A gradient pulse

In which way do gradients change the main magnetic field? A linear fashion A graduated cylinder An accelerated curve

A linear fashion

Which term describes a spin echo that is produced by two variable flip angle RF pulses? A Hahn echo. A Han Solo echo. A stimulated echo.

A stimulated echo.

Gradient echo sequences can yield either T1 or T2* characteristics, with influences caused by all of the following EXCEPT: Inhomogeneity. . Susceptibility. Chemical Shift. Aliasing.

Aliasing.

Which gradient coil can be used to spoil incoherent gradient echo pulse sequences? Frequency encoding. Phase encoding. All can be used as spoilers. Slice select gradient.

All can be used as spoilers.

A typical gradient echo sequence begins with a: Alpha pulse below 10 degrees. Alpha pulse that varies with desired image contrast. 180 degree RF pulse. 90 degree RF pulse.

Alpha pulse that varies with desired image contrast.

How do balanced gradient echo pulse sequences maintain/ enhance the steady state? By using shim alterations. By using bipolar gradient pulses. By using gradient nulling. Alterations to the RF excitation scheme.

Alterations to the RF excitation scheme.

Please list the uses of EPI imaging.

Answer:(functional MRI, cardiac and coronary vessels, interventional MRI, perfusion and blood oxygenation)

Gradient rephasing does not correct for field:

Answer:(inhomogenieties)

Which of the following types of Gradient echo pulse sequences is used to null motion artefacts from flowing blood and CSF? Balanced Gradient Echo. Incoherent Gradient Echo. Steady State Free Precession. Coherent Gradient Echo.

Balanced Gradient Echo.

Which of the following terms describer the type of gradient switching used to navigate K Space in an EPI filling? Pinball. Pinging. Blipping. Bopping

Blipping.

In the Steady State stimulated echoes contain what type of image information? T2* information Both T2 and T2* information T2 information T1 information

Both T2 and T2* information

Which of the following type of GRE pulse sequences is known for giving images angiographic, myelographic, or arthrographic effects? Coherent GRE. Steady State Free Precession (SSFP). Balanced GRE. Incoherent GRE.

Coherent GRE.

What type of gradient echo generation is depicted in the image?

Coherent Gradient Echo

What type of pulse sequence is depicted in the image?

Coherent Gradient Echo

Which type of GRE pulse sequence uses information from both the FID and the stimulated echo? Incoherent Gradient Echo. Steady State Free Precession. Coherent Gradient Echo. Balanced Gradient Echo.

Coherent Gradient Echo.

To produce the echo, a gradient echo pulse sequence uses: Gradient magnetic field only. RF pulse only. Combination of a and b. A combination of any two RF pulses.

Combination of a and b.

Which of the following is not an artefact that would happen as a result of using an EPI sequence? Loss of resolution. Cross excitation. blurring and ghosting. Chemical shift.

Cross excitation.

Which of the following terms describes the flip angle that provides optimum signal intensity for a tissue (based on T1 relaxation time)? Variable angle. Ernst angle. Hahn angle. Phase lock

Ernst angle

Which type of pulse sequence is used to obtain dynamic imaging? Steady State Free Precession. Balanced Gradient Echo. Fast Gradient Echo. Fast Spin Echo.

Fast Gradient Echo

Which of the following types of gradient echo sequences uses a pre-magnetization pulse? Steady State Gradient Echo. Balanced Gradient Echo. Fast Gradient Echo. Incoherent Gradient Echo.

Fast Gradient Echo.

Which of the following MRI principles is responsible for T2* decay? T1 recovery. Field inhomogenties. Spin lattice relaxation. Spin Spin interactions.

Field inhomogenties.

Which of the following sets of Gradient echo parameters would result in the steady state? Flip angle of 30 degrees and a TR of 40 ms. Flip angle of 70 degrees and a TR of 100 ms. Flip angle of 70 degrees and a TR of 40 ms. Flip angle of 30 degrees and a TR of 100 ms.

Flip angle of 30 degrees and a TR of 40 ms.

Which gradient(s) are applied in bipolar way in a Balanced Gradient Echo pulse sequence? Slice Select. Frequency Encoding. Phase Encoding

Frequency Encoding.(50 %)

What type of pulse sequence is depicted in the image?

GRASE

What does GRASE stand for?

Gradient And Spin Echo

What type of pulse sequence is depicted in the image?

Gradient Echo EPI

Which of the following describes an imaging technique where a train of gradient echoes are used to fill all lines of K Space in one TR? Steady State Free Precession. Single Shot Fast Spin Echo. Gradient Echo Planar Imaging. Balance Planar Imaging.

Gradient Echo Planar Imaging.

What type of echo is collected during a GRE acquisition? Spin echo TE Gradient echo The FID

Gradient echo

What type of echoes are generated in EPI?

Gradient echoes (GREs)

Gradient echo pulses sequences use which of the following to rephase the magnetic moments of Hydrogen nuclei? 180 degree refocusing pulse 90 degree rephasing pulse Gradient rephasing

Gradient rephasing

Using the table please predicted the signal intensity for fat in the steady state.

High signal intensity

Using the table please predicted the signal intensity for water in the steady state.

High signal intensity

How does balanced GE differ from coherent or rewind GE?

It uses a balanced gradient scheme to correct for phase errors in flowing blood and CSF and an alternating RF excitation scheme to enhance steady-state effects.

Which of following is not a Multi-shot method? K Sapce segmentation by echo K Sapce segmentation by acquisition K Sapce segmentation by slice

K Sapce segmentation by slice

Using the table please predicted the signal intensity for CSF in the steady state.

Low signal intensity

Using the table please predicted the signal intensity for white matter in the steady state.

Low signal intensity

What type of gradient power supply can perform both single shot EPI and traditional sequences? Over shot power supply Resonant power supply Oscillating power supply Non-resonant power supply

Non-resonant power supply

A gradient echo acquired with a small flip angle, long TR, & short TE would have which weighting? PD weighting T2 weighting T2* weighting T1 weighting

PD weighting

Which of the following terms describes the process in which the receive coil discriminates between current and past excitation phases? Phase lock Ernst angle Hahn lock Receive lock

Phase lock

How are very short TEs achieved in fast or turbo gradient echo?

Ramped sampling, partial echo, and broad receive bandwidth.

Which term describes transverse magnetization that is a result of previous excitations? Residual transverse magnetization. Residual longitudinal magnetization. Redundant transverse magnetization. Redundant longitudinal magnetization.

Residual transverse magnetization

What are two consequences of generating the steady state in GE sequences?

Residual transverse magnetization that is rephased to produce a stimulated echo. Images where contrast is dependent on T1/T2 rather than absolute values of T1 recovery time and T2 decay time.

What type of gradient power supply oscillates at a fixed frequency and amplitude? Over shot power supply. Non-resonant power supply. Oscillating power supply. Resonant power supply.

Resonant power supply.

What describes the process of keeping the transverse magnetization coherent by reversing the slope of the phase encoding gradient after readout? Spoiling Swapping Rephasing Rewinding

Rewinding

What type of pulse sequence is depicted in the image?

SE-EPI

Which of the following statements about single shot EPI is true when compared to multi shot EPI is true? Chemical shift is reduced. San time is reduced. Image blurring and distortion is reduced. There is less stress on the gradients.

San time is reduced.

Which term describes a K space technique that fills all lines of K Space in one TR. Stand Alone Shot. Staged Spiral. Single Centric. Single Shot.

Single Shot

Which of the following options would create a diffusion image with the shortest scan time? Single-shot FSE Single-shot EPI Multi-shot EPI

Single-shot EPI

What type of pulse sequence is depicted in the image?

Spin Echo EPI

What type of gradient echo generation is depicted in the image?

Steady State Free Precession

What type of pulse sequence is depicted in the image?

Steady State Free Precession

Which of the following GRE pulse sequence types use data from only the Stimulated echo?\ Steady State Free Precession. Incoherent Gradient Echo. Coherent Gradient Echo.

Steady State Free Precession.

Which of the following GRE pulse sequences usually acquires two TEs? Balanced Gradient Echo. Steady State Free Precession. Incoherent Gradient Echo. Coherent Gradient Echo.

Steady State Free Precession.

If the TR of a gradient echo pulse sequence is considerably less than the T2 (and T2*), the condition that will exist is known as: Spin rephrasing. Steady state. Spin cancellation. Spin dephasing.

Steady state

Gradient echo sequences acquired for the evaluation of hemorrhagic lesions rely on: Aliasing. Chemical shift. Susceptibility. Inhomogeneity.

Susceptibility.

Coherent gradient echo pulse sequences can acquired MR images with which of the following image weightings? T1 and PD. T2* and PD. T1 and T2. T1 and T2*

T1 and T2*

A Gradient echo acquired with a large flip angle, short TR, & short TE would have which weighting? T2* weighting T2 weighting PD weighting T1 weighting

T1 weighting

Which of the following image weightings is usually acquired when using an Incoherent Gradient Echo pulse sequence? T2 weighting. T1 weighting. PD weighting. T2* weighting.

T1 weighting.

Gradient pulse sequences can produce which of the following imaging weightings? T2* and Proton Density T1, T2, and Proton Density T1, T2*, and Proton Density T1 and T2

T1, T2*, and Proton Density

Gradient MRI pulse sequences can produce all of the following weightings except? PD weighting T2 weighting T1 weighting T2* weighting

T2 weighting

A gradient echo acquired with a small flip angle, long TR, & long TE would have which weighting? T1 weighting PD weighting T2 weighting T2* weighting

T2* weighting

Scan time for 2D GRE pulse sequences can be calculated by: TR x Phase encoding steps x NSA X number of slices. TR x shots x NSA. TR x Phase encoding steps x NSA / ETL. TR x Phase encoding steps X NSA.

TR x Phase encoding steps X NSA.

Which of the following is true in regards to the steady state? TRs are shorter than T2 relaxation times only. TRs can not be shorter than T1 or T2 relaxation times. TRs are shorter than T1 relaxation times only. TRs are shorter than T1 and T2* relaxation times.

TRs are shorter than T1 and T2* relaxation times.

During a Coherent acquisition the signal collected contains which of the following? The Hanh echo only. The FID only. The FID and the simulated echo. The gradient echo only.

The FID and the simulated echo.

What signals are sampled in coherent or rewind GE sequences?

The FID and the stimulated echo.

Which of the following is true about the FID in the steady state? The FID is the signal generated directly following the RF pulse, When it is rephased is contains T2* or T1 information. The FID is the signal generated directly following the RF pulse, When it is rephased is contains PD information. The FID is the signal generated directly following the RF pulse, When it is rephased is contains T2 information. The FID is the signal generated directly following the gradient pulse, When it is rephased is contains T2* or T1 information.

The FID is the signal generated directly following the RF pulse, When it is rephased is contains T2* or T1 information.

What is the Ernst angle?

The flip angle that produces maximum signal intensity in a tissue with a given T1 recovery time in a given TR.

Which of the following is true about RF spoiling? The receiver coil samples frequencies within the echo to pick out the correct data to be sampled. An RF pulse is used to to dephase residual magnetization so that it ins incoherent at the beginning of the next repletion.

The receiver coil samples frequencies within the echo to pick out the correct data to be sampled.

Why is the stimulated echo not sampled in incoherent or spoiled gradient echo?

There is a phase lock between the transmit and receive coils so that only the most recently created transverse magnetization is detected by the receive coil.

How do the flip angle and TR affect weighting in GE sequences?

They determine whether vectors are saturated or not and, therefore, the degree of T1 contrast in the image

Which of the following would not produce a NMR echo? Two gradient pulses. Two RF pulses. One RF pulse and one gradient refocusing pulse.

Two gradient pulses.

Gradient echo pulse sequences use which of the following types of RF pulses? 90 degree RF pulses. Variable RF pulses. 180 degree RF pulses.

Variable RF pulses.

Which of the following tissues will be hypointense on a MR image when using steady state imaging? Water White matter CSF Fat NO

White matter(50%)

Which of the following tissues will return a high signal intensity in the steady state? CSF Water Fat White matter

water(50%)