Practice Set (4) - Image Production

The precessional frequency of hydrogen at 1.5 telsa is

More questions regarding precessional frequency at 1.0T

Even more questions regarding precessional frequency at 0.5T

The coils used to alter the magnetic field during scanning are known as the

The precessional frequency of hydrogen nuclei that experience increased magnetic field strength due to gradient coils

The precessional frequency of hydrogen nuclei that experience decreased magnetic field strength due to gradient coils

There are how many pairs of gradient coils in a standard MRl system

The Z gradient alters the magnetic field strength along which axis

The Y gradient alters the magnetic field strength along which axis

The X gradient alters the magnetic field strength along which axis

The center of the magnet where the magnetic field strength remains unchanged even during the application of gradient magnetic fields is known as the

The three primary functions that gradients perform during MR scanning are

During slice selection, the Z gradient is used to select slices in which plane

During slice selection, the X gradient is used to select slices in which plane

During slice selection, the Y gradient is used to select slices in which plane

During the acquisition of sagittal images with the frequency direction S/I, phase encoding is conducted by which physical gradient

During the acquisition of coronal images with the frequency direction S/I, phase encoding is conducted by which physical gradient

During the acquisition of axial images of the brain with the frequency direction A/P, phase encoding is performed by which physical gradient

During the acquisition of axial images of the body with the frequency direction L/R, phase encoding is performed by which physical gradient

During the acquisition of sagittal images with the phase direction A/P, frequency encoding is performed by which physical gradient

During the acquisition of coronal images with the phase direction L/R, frequency encoding is conducted by which physical gradient

During the acquisition of axial images of the body with the phase direction A/P, frequency encoding is performed by which physical gradient

During the acquisition of axial images of the brain with the phase direction L/R, frequency encoding is performed by which physical gradient

In MR imaging, slice thickness is determined by which factor(s)

In MRI, thin slices are achieved by applying a _______ gradient slope or a ______ bandwidth

In MRI, thick slices are achieved by applying a ________ gradient slope or a
_______ bandwidth

The range of frequencies that is sampled during frequency encoding is known as the

The range of frequencies that is transmitted by the RF pulse is known as the

In MR imaging, the interslice gap is determined by which factor(s)

The gradient that is turned on during the application of the 90 degree excitation pulse and the 180 degree RF pulse is known as

The gradient that is turned on during signal sampling is known as the

The gradient that is turned on just before the 180 degree rephasing pulse is known as the

The amplitude ofthe phase and frequency encoding gradients determines the dimension of what parameter

The frequency encoding gradient is also known as the _______ because it is turned on during the sampling of signal

The theorem that states that a frequency must be sampled at least twice in order to reproduce it reliably is known as the

The rate at which signal samples are taken during frequency encoding is known as the

During the sampling of signal, the sampling rate is directly proportional to the

During the sampling of the signal, the sampling time is inversely proportional to

The spacial location of signal according to its precessional phase is known

The spacial location of signal according to its precessional frequency is known as

The area within the array processor where spatially located information is stored is known as

The magnitude of the phase shifts between two points within a patient is determined by which factor

The process that uses mathematical conversions to calculate the amplitude of individual frequencies is known as

The number of times each signal is sampled with the same value of the phase encoding gradient is known as

The higher the number of excitations that are acquired the more K space that is filled

In conventional spin echo sequences, how many phase encoding steps must be selected to fill 128 lines of K space

In conventional spin echo sequences, how many phase encoding steps must be selected to fill 256 lines of K space

Which parameter(s) effect total scan time

During a conventional spin echo pulse sequence, each slice is selected, phase encoded, and frequency encoded once per TR

The horizontal axis of K space represents which axis of the image (with corrected answer)

The vertical axis of K space represents which axis of the image (with corrected answer)

The area of K space filled with the shallowest phase encoding slopes is known as

The area of K space that is filled with the steepest phase encoding gradient slopes is known as

Image data along both the phase and frequency axis with the highest signal amplitude is stored in which area of K space

Image data along both the phase and frequency axis with the lowest signal amplitude is stored in which area of the K space

When the phase encoding gradient is activated, steep slopes produce what type of signal amplitude

When the phase encoding gradient is activated, shallow slopes produce what type of signal amplitude

When the phase encoding gradient is activated, medium slopes produce what type of signal amplitudes

When the amplitude of the phase encoding gradient increases, the amount of phase shift along the gradient

When the phase encoding gradient is activated, steep slopes produce data with what type of spatial resolution

Image data with high spatial resolution is stored in which area of K space

Image data with low spatial resolution is stored in which area of K space

The process of filling K space by sampling only half of the echo and interpolating the rest is known as

The process of filling only a percentage of K space with acquired data and filling the rest with zeros is known as

Which method of image acquisition acquires all of the data from one slice before acquiring data from the next slice

Which method of image acquisition fills one line of K space for each slice in the sequence before it moves to the second line of K space

Which method ofimage acquisition acquires data from an entire volume of tissue, then uses a method called slice encoding to separate the images

The thickness of an MRI image can be changed by which of the following methods

The term used to describe a volume element is known as

The number of picture elements used to make up an image is known as

The ability to distinguish one structure from another on an image is known as

The term used to describe a picture element is known as a

The size of the area being displayed on an MR image is known as

The depth of a volume element is determined by what parameter

The height and width of a picture element is determined by what parameter(s)

A volume element that has the same height, width, and depth is known
as

A voxel that is unequal in height, width, and depth is known as

Three characteristics commonly used to define the quality of an MRl image are

The difference in brightness between two regions of an image is known

Bright pixels on an MRI image represent what type of signal

The clarity with which different areas of an image are distinguished is known
as

The proportion of signal actually used to construct an image relative to the amount of background noise is known as

An image with a grainy appearance usually represents an image with

Noise that degrades image quality in a specific location within an MRI image is known as

Noise that generally degrades overall quality of an MRI image is known

Which of the following is a parameter that directly affects signal to noise ratio

The term "Trade-off parameters" is used to describe parameters that affect each other inversely

When magnetic field strength increases, signal to noise ratio

When voxel size decreases, signal to noise ratio

When pixel size increases, signal to noise ratio

When bandwidth is increased, signal to noise ratio

When repetition time is increased, signal to noise ratio

When echo time is increased, signal to noise ratio

When field of view decreases, spatial resolution

When field of view is increased, signal to noise ratio

When the number of excitations is increased, spatial resolution

When image matrix is increased, spatial resolution

When slice thickness is increased, signal to noise ratio

When slice spacing increases, signal to noise ratio

When image matrix is decreased, spatial resolution

When TE is decreased, the spatial resolution

When TR is increased, acquisition time

When the number of excitations is decreased, acquisition time

When image matrix increases, acquisition time

With the parameters given, which protocol gives the highest signal to noise ratio

With the parameters given, which protocol gives the highest spatial resolution

With the parameters given, which protocol has the longest acquisition time

With the parameters given, which protocol gives the highest signal to noise ratio

As bandwidth increases, sampling time

As bandwidth decreases, sampling time

Which of the following 'logical' gradients is known as the frequency encoding gradient

Which of the following 'logical' gradients is known as the phase encoding gradient

Which of the following 'logical' gradients is known as the slice selection gradient

In plane pixel size can be determined by which of the following methods

Which of the following is the formula for determining scan time for a 3D FT pulse sequence