Mri

Front 1

increasing the flip angle yields images with

Back 1

more t1 info

Front 2

reducing the flip angle yields images with

Back 2

less t1 info

Front 3

reducing the tr yields images with

Back 3

more t1 info

Front 4

increasing the te yields images with

Back 4

more t2 info

Front 5

increasing the tr yields images with

Back 5

less t1 information

Front 6

reducing the te yields images with

Back 6

less t2 info

Front 7

reducing the te does what to snr

Back 7

increases snr

Front 8

reducing the etl

Back 8

increases scan time

Front 9

increasing the flip angle does what to snr

Back 9

increases up to Ernst angle

Front 10

increasing the matrix does what to snr

Back 10

decreases

Front 11

increasing the slice thickness does what to snr

Back 11

increases snr

Front 12

increasing the nsa does what to scan time

Back 12

increases scan time

Front 13

increasing the slice thickness has what affect on scan time

Back 13

doesn't affect scan time

Front 14

increasing the phase matrix does what to scan time

Back 14

increases scan time

Front 15

increasing the fov does what to scan time

Back 15

does not affect scan time

Front 16

for a given tissue with a given t1 relaxation time and tr, the flip angle,which will result in the max signal for that tissue is

Back 16

the Ernst angle

Front 17

increasing the number of slices in a 2d acquisition does what to scan time

Back 17

doesn't affect scan time

Front 18

increasing the te does what to scan time

Back 18

doesn't affect scan time

Front 19

increasing tr does what to scan time

Back 19

increases scan time

Front 20

when triggering a scan from a pt ecg, the tr of the sequence is determined by the

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patients heart rate

Front 21

in a fast spin echo sequence the central lines of k space are associated with the

Back 21

effective te

Front 22

the effective te in a fast spin echo pulse sequence determines the

Back 22

image contrast

Front 23

increasing the matrix in the frequency direction from 256 to 512 will

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have no effect on scan time

Front 24

using a 3d acquisition increasing the number of slices from 64 to 128 does what to scan time

Back 24

doubles it

Front 25

using a 3d acquisition the number of slices allowed when increasing the tr

Back 25

is not affected

Front 26

using a conventional spin echo multi-line sequence, the number of slices allowed when increasing the tr from 20-40ms

Back 26

decreases

Front 27

using a conventional spin echo multislice sequence the number of slices allowed when increasing the te

Back 27

increases by a factor of tr/te

Front 28

to rephase the signal from moving spins, gradient moment nulling techniques use a

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gradient

Front 29

gradient moment nulling iss most effective when correcting for motion induced signal loss from

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slow constant flow

Front 30

increasing the number of phase encodings (matrix) from 128 to 256 (by a factor of 2) the SNR

Back 30

decreases

Front 31

a chemical or spectral fat suppression sequence will suppress the signals from fat based on the

Back 31

processional frequency of fat

Front 32

in choosing the direction of phase encoding, the Technologist usually considers the direction in which the

Back 32

motion artifacts traverse the least tissue or areas of interest

Front 33

if a stir sequence using a tr of 3000, a te of 20, and a t1 of 140 produces an image with dark fat and bright water, the contrast in such an image is primarily based on

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t1

Front 34

reducing nsa will reduce the scan time and

Back 34

decrease the SNR

Front 35

increasing the number of phase encodings will produce an image with

Back 35

decreased vowel volume

Front 36

doubling the number of signal averaged will

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increase the SNR by the square root of 2

Front 37

between slices 2 d acquisitions generally require

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gaps

Front 38

the SNR will increase in a 3d sequence with an increase in

Back 38

fov and number of slices

Front 39

in a conventional spin echo multislice sequence, it is possible to create multiple images each with different amounts of

Back 39

t2 weighting

Front 40

the time during which the frequency encoding gradient is on

Back 40

increases with a reduction in receiver bandwidth

Front 41

increasing the receiver bandwidth does what to the available etl

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nothing

Front 42

decreasing the receiver bandwidth does what to number of slices

Back 42

decreases

Front 43

decreasing the receiver bandwidth does what to susceptibility artifact

Back 43

increases

Front 44

decreasing the receiver bandwidth does what to readout time

Back 44

increases

Front 45

decreasing the receiver bandwidth does what to chemical shift

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increases

Front 46

decreasing the receiver bandwidth does what to snr

Back 46

increases

Front 47

a stir can suppress signal from

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fat and gadolinium enhanced lesions

Front 48

another name for ti is

Back 48

tau

Front 49

in an inversion recovery pulse sequence, the time between the initializing 180 pulse and the 90 pulse is known as

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ti

Front 50

in an inversion recovery pulse sequence, image contrast is controlled by

Back 50

tr te and ti

Front 51

2d conventional spin echo multislice pulse sequence scan time equation

Back 51

TR * SLICES*NSA* PE

Front 52

in a gradient echo sequence, reducing the flip angle while holding the TR constant reduces

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saturation

Front 53

as the te increases

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snr decreases

Front 54

as the tr increases

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snr increases up to a point

Front 55

reducing the television does what to contrast based on t2 relaxation times

Back 55

reduces

Front 56

reducing the tr down to or below the t1 relaxation time of the tissue does what to snr and saturation

Back 56

decrease snr and increase saturation effects

Front 57

increasing the te does what to contrast based on t2 relaxation times of tissues

Back 57

increases

Front 58

complete saturation is a condition where

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longitudinal mag is not allowed to recover between excitations

Front 59

gradient echo sequences use flip angles

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to control saturation effects

Front 60

the presaturation pulses usually occur

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prior to the excitation pulse

Front 61

presaturation pulses are often used to

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reduce flow artifacts

Front 62

in a spin echo sequence the time between the 90 pulse and the 180 pulse is

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.5 TE

Front 63

the time between excitation pulse is known as

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TR

Front 64

when using parallel imaging to reduce the acquisition times what happens to snr and spatial resolution

Back 64

snr is reduced and spatial resolution isn't affected

Front 65

in order the reconstruct an image acquired using parallel imaging what may be required

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reference or calibration scan

Front 66

automated bolus detection,test bolus, and real time Fluoro triggering can all be used for what

Back 66

ce mra

Front 67

the intrinsic contrast mechanism with regard to fmri is

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the bold effect

Front 68

in 3d tof and using mip technique what appears bright and is the same as flow within a vessel

Back 68

tissues or substances with extremely short t1 relaxation times

Front 69

the basic mri principle with regard to Mr spectroscopy is

Back 69

chemical shift

Front 70

when performing a dynamic perfusion exam of the brain..using gadolinium contrast what is the result of t2 shortening

Back 70

reduced Mr signal

Front 71

changeling the bvakue alters what

Back 71

amplitude timing and duration of diffusion gradients

Front 72

the main purpose of producing/calculating the Adc map is to

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eliminate the t2 shine through

Front 73

cine studies are often performed on various joints, the main purpose is to

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visualize motion and function

Front 74

each frame of cardiac cine sequence shows the heart in

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different phases of the cardiac cycle

Front 75

cardiac cine acquisitions typically utilize what type of pulse sequence

Back 75

gradient echo

Front 76

a major advantage of 2d tof sequence over a 3d tof is the ability to

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image larger areas without saturation of flowing blood

Front 77

a major advantage of 3d tof techniques over 2d tof is the ability to

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visualize smaller vessels

Front 78

I'm a phase contrast technique it is possible to use the data to determine the

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direction of blood flow

Front 79

phase contrast techniques produce images in which the signal intensity withing the vessel is dependent on

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velocity of flowing blood

Front 80

in a tof sequence flowing blood is hyperintense relative to stationary tissue because of

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flow related enhancement

Front 81

in a tof sequence the tissue is hyperintense relative to flowing blood because of

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saturation effects

Front 82

in a spin echo sequence flowing blood is normally seen as a signal void because

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te is too long to image flow and 90/180 pulse are both slice selective

Front 83

single order gradient moment nulling doesn't compensate for

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accelerated flow or reverse flow

Front 84

blood flow velocities are greatest

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at the center of a vessel

Front 85

to minimize the loss of signal due to dephaseling within a voxel what is used

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small vowels and short te

Front 86

the removal of signal from vessel in an mra sequence is achieved by

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spatial presaturation

Front 87

the signal intensity on diffusion sequences is related to

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amount of diffusion

Front 88

the signal intensity on pc mra sequences is related to

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velocity induced Phase shift

Front 89

the signal intensity of tof mra sequences is related to

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flow related enhancement

Front 90

the mra sequence that can be made sensitive to any flow velocity is

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3d phase contrast mra

Front 91

the mra sequence that is sensitive to flow direction is

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3d phase contrast

Front 92

the mra sequence that is most sensitive to smaller vessels is

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3d tof

Front 93

the mra sequence that is least sensitive to slow flow is

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3d tof

Front 94

a major advantage of mra over conventional angiography is that

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multiple views can be produced from a single acquisiton

Front 95

normal blood flow is known as

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turbulent flow

Front 96

The swirling blood that occurs just past three area of stenosis is known as

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vortex flow

Front 97

blood flow at the area of stenosis is known as

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accelerated flow

Front 98

normal blood flow is known as

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laminar flow

Front 99

cardiac analysis is performed with a technique using sat bands to assess the wall motion is known as

Back 99

myocardial tagging

Front 100

fourier transformation is performed in the

Back 100

array processor

Front 101

what converts signal data from the fid into the spectrum

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fourier transformation

Front 102

the technique by which the signal data is modified from the time domain to the frequency domain is known as

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fourier transformation

Front 103

a 3d dataset that displays what appears to be a 3d image of anatomy is also known as

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volume rendering

Front 104

to better visualize abdominal organs with and without contrast enhancement what is used

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subtraction

Front 105

collecting low frequency data points in K space at the start of the scan in spiral fashion is known as

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elliptic centric

Front 106

collecting low frequency data points in K space at the start of the scan in rectilinear fashion is known as

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centric

Front 107

in order to produce a high quality reformatted image, the Aquisition voxel should be what

Back 107

isotropic

Front 108

creating images in various planes from a 3d dataset is accomplished by

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multiplanar reformatting

Front 109

to evaluate the cow 3d tof mra sequences are acquired and background tissue is carved out to provide better visualization..this is called

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segmenting

Front 110

to evaluate the cow, 3d tof mra sequences are acquired and displayed as an axial view of all the vasculature..this is known as

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collapsed image

Front 111

the create projection image in mra the technique most commonly employed is

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maximum intensity pixel

Front 112

acquiring half if the phase views of k space and then interpolation the data for the other half is a technique known as

Back 112

half fourier

Front 113

with conventional spin echo each line of k space is filled in each

Back 113

te period

Front 114

one direction of k space represent phase and the other represents

Back 114

frequency

Front 115

TR*NSA*#PE*#slices is the equation for

Back 115

3d volume acquisiton

Front 116

the slices in 3d acquisiton are produced by

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a phase encoding gradient applied to the slice selection direction

Front 117

#pe/etl calculates

Back 117

number of shotd

Front 118

in a fse sequence the etl is increased by a factor of 4, what happens to scan time

Back 118

increased by factor of 4

Front 119

scan time for 2d fse pulse sequence equation

Back 119

tr* pe*NSA/etl

Front 120

tr*#pe*nsa

Back 120

equation for 2d ir, 2d gre,2d se

Front 121

mrv- where should the sat band be placed

Back 121

inferior

Front 122

cow - where should sat band be placed

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superior

Front 123

carotid arteries, where should say band be placed

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superior

Front 124

mra of Ivc,where should sat band be placed

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superior

Front 125

sense, smash, grappa are all what types of imaging

Back 125

parallel

Front 126

in a balanced great acquisition the contrast weighting is

Back 126

weighted for the ratio of t2/t1

Front 127

what sequence does Ms plaques appear hyperintense relative to csf

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t2 flair

Front 128

what sequence is used to maximise the bold effect

Back 128

gradient echo

Front 129

an epi sequence is described as

Back 129

a train of gradient echos

Front 130

to null signal from a specific tissue using an inversion recovery sequence, an inversion time that is how much of the t1 relaxation should be used

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69%

Front 131

a flair sequence suppresses the signal from

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Ms plaques, gadolinium, and fat

Front 132

gradient echo sequences acquired for the evaluation of hemorrhagic lesions rely on

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susceptibility

Front 133

gradient echo sequences can yield what two types of characteristics

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t1 or t2*

Front 134

dynamic enhanced.mra sequences of the renal arteries are performed with the use of

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incoherent gradient echos

Front 135

gradient echo sequences acquired from fluid are also known as

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coherent, steady state, t2* gradient echos

Front 136

when a gradient echo sequence is acquired for dynamic contrast enhanced imaging if the liver what is performed

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spoiling

Front 137

in fse sequence acquired with effective te, scan time can be reduced by the selection of

Back 137

longer etl

Front 138

in fse blurring can be reduced by

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shorter etl

Front 139

in fse sequence spatial resolution is associated with

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high amplitude phase encoding gradients

Front 140

in fse sequence the effective te is performed with what type of phase encoding gradients

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low amplitude

Front 141

the readout gradient is also known as the

Back 141

frequency gradient

Front 142

the gradient that is on during the production of the echo

Back 142

frequency

Front 143

phase encoding is performed when in relation to frequency

Back 143

prior

Front 144

if the tr of a gradient echo pulse sequence is considerably less than the t2 the condition that will exist is

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steady state

Front 145

the gradient that is on during the production of the echo

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frequency encoding gradient

Front 146

the 180 pulse corrects for

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Mag field in homogeneity es, chemical shift, mag susceptibility

Front 147

a typical gradient echo sequence begins with

Back 147

alpha pulse that varies with desired image contrast