Mri Mock Review

Front 1

RF shielding in the MR scan is accomplished by:

Back 1

Copper

Front 2

The average humidity in the scan room needs to be:

Back 2

50-70%

Front 3

The temperature in the scan room should be around:

Back 3

65-75 degrees f

Front 4

Superconductive magnets use____________wiring for most of the coils inside the scanner.

Back 4

titanium
(Niobium Titanium)

Front 5

In order to form images, Magnetic resonance imaging employs:

Back 5

radio waves and magnetic fields

Front 6

A vector possesses both:

Back 6

magnitude and direction

Front 7

On a T2 weighted img, which bandwidth would give the best SNR? 64, 16, 8, 120 ?

Back 7

8

Front 8

The Larmor frequency of hydrogen nuclei in a 1.5T mag field is:

Back 8

63.2 mHz

Front 9

The Larmor frequency of hydrogen nuclei in a 1.0 T magnetic field is:

Back 9

42.6 mHz

Front 10

Represent the Larmor equation

Back 10

Wo= yBo

Front 11

The Larmor equation is represented by which of the following: Bo=yF | F=yBo | M=Bo | *=Bo F |

Back 11

F=yBo

Front 12

Wo in Wo=Boy refers to:

Back 12

Frequency

Front 13

y in "Wo=Boy" refers to:

Back 13

Gyromagnetic ratio

Front 14

Bo in "Wo=Boy" refers to:

Back 14

The strength of the magnet at the center of the bore (B#0)

Front 15

The ratio of the magnetic moment to the angular momentum of a hydrogen nucleus is:

Back 15

gyromagnetic ratio

Front 16

States that voltage applied to a closed loop of wire will produce a magnetic field

Back 16

Faraday's Law of Induction

Front 17

This signal occurs after the vector has been moved to the transverse plane, is free of the RF pulse, & produces no spatial information

Back 17

FID or "dud"

Front 18

The effect of narrowing the bandwidth on signal to noise

Back 18

increases

Front 19

Spin lattice relaxation; regrowth of longitudinal magnetization back to equilibrium is know as what relaxation?

Back 19

Longitudinal relaxation
(T1)

Front 20

The T1 longitudinal relaxation, is the time required for the tissue's longitudinal magnetization to recover_____% of it's equilibrium magnetization?

Back 20

63%

Front 21

Where is Isocenter?

Back 21

at the intersection of the x,y, and z planes

Front 22

Contrast goes to the________ of k-space and resolution is places____________ of k-space.

Back 22

center / outer edges

Front 23

Transverse relaxation is also known as:

Back 23

T2 relaxation
(T2 decay)

Front 24

The function of the shim coils in an MR system is to:

Back 24

maintain magnetic field homogeneity

Front 25

Another name for the "read-out" encoding gradient in an MR scan is:

Back 25

frequency encoding

Front 26

The range of RF frequencies in the RF pulse is called the:

Back 26

bandwidth

Front 27

The rise time of the gradients is:

Back 27

time interval to the gradient reaches full magnetic field amp

Front 28

Is aliasing caused by oversampling or undersampling in which too much data is collected

Back 28

Undersampling (too small FOV)

Front 29

These artifacts occur in gradient echo sequences as an area of signal void and geometric distortion, at the air-tissue interface and as the result of refocusing spin by gradient reversal instead of using a 180

Back 29

Susceptibility artifacts

Front 30

Also known as truncation artifact and it is the result of undersampling.

Back 30

Gibbs artifact.

Front 31

The gradient amplitude affects the:
(same as Gradient)

Back 31

minimum FOV that can be used & minimum slice thickness used

remember Frank Smokes Marijuanna
FOV; SliceThickness; Matrix

Front 32

T/F
The following are ALL support systems for the MRI system:
chilled water; Halon system; oxygen alarms

Back 32

True

Front 33

Dewars are nonferromagnetic cylinders for the:

Back 33

cryogens of liquid helium

Front 34

A resistive magnet system is powered by:

Back 34

electricity

Front 35

The most important advantage of MR over CT and X-ray is:

Back 35

improved soft tissue detail

Front 36

For an MR signal to be received net magnetization must be in phase and:

Back 36

in the transverse plane

Front 37

If you increase the matrix you _________ the signal to noise.

Back 37

decrease

Front 38

If you decrease the matrix, you _________ the signal to noise.

Back 38

Increase

Front 39

If you change the FOV from 120mm to 240mm will SNR increase or decrease?

Back 39

Increase

Front 40

If you change the FOV from 120mm to 240mm, you increase the signal to noise by a factor of:

Back 40

4

Front 41

Unit used to describe precessional frequency

Back 41

Megahertz (mHz)

Front 42

Increasing the Field of View (FOV), will result in all of the following except: increase in signal to noise; increase in resolution; increase in partial volume averaging

Back 42

except increase in resolution; both PVA and SNR increase

Front 43

Faraday's Law of Induction states that if a loop of wire connected to a current will produce:

Back 43

magnetism

Front 44

How is the homogeneity of the magnetic field measured?

Back 44

ppm (parts per million)

Front 45

The direction of the magnetic field of a superconductive magnet is:

Back 45

horizontal

Front 46

The direction of the magnetic field in a permanent magnet is:

Back 46

vertical

Front 47

The transmit bandwidth affects all of the following except:
Slice thickness/ FOV/ Matrix/ Contrast

Back 47

Contrast

Front 48

Phase contrast imaging involves:

Back 48

VENC is selected, bipolar gradients, used to image complex flow

Front 49

The initial RF pulse that is transmitted into the body must match:

Back 49

The Larmor frequency of the hydrogen protons

Front 50

An artifact which results from narrowing the receive bandwidth is _______ and the artifact is in the _______ direction.

Back 50

Chemical shift / frequency

Front 51

The decay of transverse magnetization is known as

Back 51

spin spin relaxation, T2

Front 52

If a coil is damaged or improperly tuned, there will be a decrease in

Back 52

Signal to noise

Front 53

Bo homogeneity is adjusted by:

Back 53

adjusting the current in the shim coils

Front 54

A magnetic field strength of 1 Tesla equals

Back 54

10,000 Gauss

Front 55

_______ relaxation is referred to as the time that it takes 63% of the protons to realign back to equilibrium

Back 55

T1

Front 56

After the 90 RF pulse, hydrogen protons dephase; in order to obtain a spin echo signal a

Back 56

180 RF is used

Front 57

Where would you place RF saturation bands in order to saturate out the veins of the leg?

Back 57

Inferior

Front 58

________ relaxation is defined as the time that it takes 63% of the transverse magnetization to decay.

Back 58

T2

Front 59

The flip angle which gives the maximum signal

Back 59

Ernst angle

Front 60

Spin density is another term for

Back 60

Hydrogen density or Proton density

Front 61

The receive bandwidth is associated with the slope of the ________ gradient

Back 61

Frequency encoding gradient

Front 62

T2* is the result of T2 dephasing and

Back 62

Inhomogeneity within the patient and the field

Front 63

The gradient which is used to acquire a coronal image is the _____ gradient

Back 63

Y gradient

Front 64

Precessional frequency is calculated by multiplying the strength of the static magnetic field and a constant, referred to as

Back 64

The gyromagnetic ratio
Wo=yBo

Front 65

The RF energy used in MRI is classified as

Back 65

Electromagnetic radiation

Front 66

Which gradient is used to aquire an oblique coronal of the shoulder?

Back 66

a combination of 2 gradients

Front 67

Spectroscopy, is the oldest form of MRI; which of the following are true?

Back 67

frequency distribution of a signal / non-invasive molecular composition of tissue / NAA, Cr, and Cho are measured in order to determine if an area is cancerous

Front 68

During thermal equilibrium, protons precess

Back 68

Out-of phase

Front 69

Frequency is defined as

Back 69

The rate of phase change per unit time

Front 70

Materials such as iron which have a strong attraction to the magnetic field are called

Back 70

Ferromagnetic

Front 71

As the slice thickness is increased, the spatial resolution is

Back 71

Decreased

Front 72

Winning a Nobel Peace prize for his efforts in MRI, some consider___________the father MRI

Back 72

Damadian / Lauterbur

Front 73

The job of the gradients is to

Back 73

Spatially encode data

Front 74

Slice thickness is controlled by

Back 74

The slope of the gradient

Front 75

In order to acquire an axial slice, which gradient is applied?

Back 75

Z gradient

Front 76

To produce a sagittal slice, which physical gradient is applied?

Back 76

X gradient

Front 77

Where would a technologist scan when looking for a Chiari malformation

Back 77

craniocervical junction

Front 78

The gyromagnetic ratio for hydrogen on a 1.5 Tesla magnet is

Back 78

63.86 Megahertz/Tesla

Front 79

The amount of RF needed to produce a flip of 90 degrees is determined by

Back 79

The amplitude of the RF pulse; the duration of the RF pulse; the strength of the magnetic field

Front 80

The gradient which is applied during the sampling of the echo, also called the readout gradient

Back 80

Frequency gradient

Front 81

Tissues with a short T1 relaxation time appear _______ on T1 weighted images.

Back 81

hyperintense/ bright

Front 82

Chemical shift artifact occurs because

Back 82

Fat and water precess at different frequencies

Front 83

Chemical shift artifacts are more pronounced as

Back 83

The receive bandwidth is decreased; the field strength increase

Front 84

FID refers to

Back 84

free induction decaty

Front 85

The measure of the extent to which a substance becomes magnetized is known as its

Back 85

magnetic susceptibility

Front 86

High and low intensity bands are seen as the result of undersampling, these artifacts are called Truncation or

Back 86

Gibbs

Front 87

Susceptibility effects are reduced by

Back 87

Decreasing the TE

Front 88

T2 relaxation occurs faster than T1 relaxation

Back 88

True

Front 89

Mean to decrease repiratory motion include: Respiratory gating / Increasing the number of signal averaged / Having the patient hold their breath/ All of the above

Back 89

All of the mentioned help decrease rep motion

Front 90

Which of the following sequences would most decrease the effects of magnetic susceptibility?

Back 90

FSE or TSE spin echo

Front 91

Black and white banding artifact on the edge of the FOV; often seen on a gradient echo coronal localizer of the abdomen

Back 91

Moir'e artifact; zebra artifact

Front 92

In order to display subtle hemorrhage in the brain, which sequence would be best?

Back 92

Gradient echo

Front 93

Raw data is often referred to as

Back 93

K-space

Front 94

A light bulb going "bad" in a MR scan room could cause

Back 94

Zipper/ RF artifacts

Front 95

In order to diminish the appearance of Gibb's artifact, a technologist should

Back 95

increase the matrix

Front 96

Using TR of 3000ms, as the Echo Time (TE) increases, T2 weighting will

Back 96

Increase

Front 97

Artifacts result from failure to sample data for a sufficient amt of time. Bands of high and low signal intensity running parallel to the tissue interface -occasionally seen in the cervical cord are called

Back 97

Gibbs artifacts

Front 98

During the imaging process, magnetic field gradients may cause time-varying induced

Back 98

Eddy currents

Front 99

T1 contrast is predominantly controlled by

Back 99

TR

Front 100

In order to double the SNR, the NSA must increase by a factor of

Back 100

Four

Front 101

Chemical shift artifacts are more pronounced at

Back 101

high field strengths, and reduced bandwidths

Front 102

The FDA limit on time-varying magnetic fields is:

Back 102

a limit to where the patient experiences tingling or pain

Front 103

What occurs when the interspace thickness between slices is 0 or less than 25%?

Back 103

cross excitation/ cross talk

Front 104

The strength of the magnetic field is measured in

Back 104

Gauss/centimeter or mT/meter

Front 105

At isocenter, the field strength is measured in

Back 105

Tesla

Front 106

The most important element in maintaining a safe MRI environment is

Back 106

Education

Front 107

Name some properties of the MRI signal that we can measure

Back 107

Phase, Frequency, amplitude

Front 108

In the presence of a magnetic field, the hydrogen protons wobble, this is called

Back 108

Precession

Front 109

As you increase the repitition time, what effects occur

Back 109

The time increases, the SNR increases, the number o slices available increase

Front 110

As you increase the repitition time, what effects occur

Back 110

The time increases, the SNR increases, the number of slices available increase

Front 111

During pre-scan, the center frequency of the RF should be tuned to match the

Back 111

Larmor frequency of hydrogen protons

Front 112

106. According to the ____________ theorum, a signal must be sampled at least twice per cycle in order to represcent it accurately

Back 112

Nyquist theorem

Front 113

If you decrease the voxel volume, you also decrease___________

Back 113

Partial volume averaging & Susceptibility artifacts

Front 114

The term that represents the difference in brightness beween 2 regions on an image is

Back 114

image contrast

Front 115

Which coil is more sensitive to alaising artifacts? Small coil with a smalll FOV or Large coil with small FOV

Back 115

Large coil with a small FOV

Front 116

Another term that refers to a patient's body or a coil toughing the side of the magnet's bore, causing decreased SNR is

Back 116

decoupling or detuning

Front 117

A _________ is a non-ferrous storage tank for liquid helium, used in a superconducting magnet system.

Back 117

Dewar

Front 118

In an MR system, a coil of wire wound in the form of a long cylinder is

Back 118

solenoid coil

Front 119

With conventional spin echo imaging, each line of k-space is filled with each

Back 119

Repetition time (TR)

Front 120

If the number of signal averages (NSA/NEX) is increased by a factor of 2, the scan time will

Back 120

double

Front 121

If the number of signal averages (NSA/NEX) is increased by a factor of 2, the Signal to noise will

Back 121

increase by the √2

Front 122

Chemical misrepresentation: a.) Occurs because fat & water are out of phase in the same voxel..b) Occurs when an echo time is selected that accents the difference in fat and water.

Back 122

c) Is seen as a black ring around tissue.
d) All of the above

Front 123

Specific absorption rate refers to

Back 123

amount of energy deposited by RF in a certain amount of tissue

Front 124

The U.S. governing body which is responsible for governing MRI is

Back 124

FDA

Front 125

The limits for SAR in the FDA guidelines for whole body imaging are

Back 125

4 W/Kg

Front 126

The "dB/dt effect" such as muscular twitches in the hand, face, and back most likely occur with

Back 126

Echo planar imaging/DWI

Front 127

What tissue is suppressed during FLAIR imaging

Back 127

Water/fluid

Front 128

The main concern associated with radio frequency is

Back 128

Tissue heating

Front 129

The amount of RF that can be deposited in a certain amount of tissue is the

Back 129

SAR

Front 130

A Capnometer is used to measure

Back 130

carbon dioxide levels

Front 131

The FDA limits the increase in a patient's core body temperature to

Back 131

1 degree Celsius

Front 132

The force with which an object is attracted to a magnetic field will be dependent upon

Back 132

The mass of the object;
The field strength of the magnet;
The ferromagnetic properties of the object

Front 133

Since these two areas of the body do not dissipate heat well, they are very sensitive to RF

Back 133

Lens of eyes and testes

Front 134

Who should be screened

Back 134

Any & everyone entering the scan room

Front 135

Lengthening the TR will have all of the following except:
increasing scan time/ increasing SNR/ Increasing T1 / Decreasing T1

Back 135

Increasing T1

Front 136

MR patient screening procedures could include

Back 136

checking for aneurysm clips, asking if patient has worked w sheet meta, asking pt if he has had heart surgery

Front 137

The best plane in order to display the rotator cuff is

Back 137

coronal oblique

Front 138

What material should wheelchairs, stretchesrs, and stepstools be made of in order to safely enter the MRI scan room?

Back 138

non-ferrous material

Front 139

Are called time varying magnetic fields (TVMF)

Back 139

gradients

Front 140

T/F
A peripheral gating device on the finger or toe may be used to monitor critically ill patients

Back 140

False

Front 141

Cardiac pacemakers, cochlear implants, and artificial hip replacement are all absolute contraindications for MRI scanning

Back 141

False; all except hip replacement are

Front 142

MRI IV contrast agents are considered__________agents

Back 142

paramagnetic

Front 143

Conscious sedation may be a concern as it may

Back 143

depress respiration

Front 144

If MRI is indicated during the first trimester, the scan is usually avoided if possible

Back 144

true

Front 145

A normal O2 saturation for a patient undergoing MR scanning is

Back 145

85 - 100%

Front 146

A quench is defined as the

Back 146

rapid collapse of magnetic field and release of heat and sudden boil- off of cryogens

Front 147

Maximum field strength that is FDA approved for infant and adult patient scanning is

Back 147

8.0 T

Front 148

As blood moves across the magnetic field, there may be an elevation of the patient's T-wave. This phenomenon is called

Back 148

Hemodynamic effect or Magnetic Hydrodynamic effect

Front 149

Individuals with pacemakers must remain outside the _____ line

Back 149

5 gauss

Front 150

This is the name of a malignant kidney tumor commonly found in children

Back 150

Wilms tumor

Front 151

There are _____ contraindications to gadolinium

Back 151

No known

Front 152

The cranial nerve known as the facial nerve is the

Back 152

7th facial nerve

Front 153

Which cranial nerves are considered the IAC

Back 153

7th and 8th are considered the IAC

Front 154

For a patient with Bells Palsy which cranial nerve would be involved

Back 154

7th

Front 155

The best view to show the Achilles tendon

Back 155

sagittal

Front 156

which of the following is hypointense post contrast?
mucosa/ pituatary/ pineal/ basal ganglia

Back 156

basal ganglia

Front 157

Avascular necrosis is predominantly in the

Back 157

Head of the femur

Front 158

The duramater lining beween the two hemispheres of the brain is called the

Back 158

falx cerebri

Front 159

The division between the temporal lobe and the frontal lobe is the

Back 159

Sylvian fissure

Front 160

The inner lining of the uterus is called the

Back 160

endometrium

Front 161

The inner lining of the uterus is called the

Back 161

endometrium

Front 162

Name the three components of the brainstem

Back 162

Midbrain, pons, medulla

Front 163

Name the components of the diencephalon

Back 163

Thalmus, epithalmus, subthalmus, hypothalamus

Front 164

Which positions are used to display the Internal auditory canal (IAC)

Back 164

Axial and Coronal

Front 165

Which positions are used to display the Internal auditory canal (IAC)

Back 165

Axial and Coronal

Front 166

Which positions are used to display the pituitary gland?

Back 166

Sagittal and coronal

Front 167

Which vessel is located directly in front of the pons

Back 167

Basilar artery

Front 168

Which vessel is the first to branch off to the aorta

Back 168

Right Coronary artery

Front 169

The first vessel to branch off the aortic arch is

Back 169

The brachiocephalic artery

Front 170

Which projection best displays the cruciate ligaments of the knee

Back 170

Sagittal

Front 171

Which projection best displays the collateral ligaments of the knee

Back 171

Coronal

Front 172

The inferior sagittal sinus drains into

Back 172

Jugular vein

Front 173

Where is CSF produced

Back 173

Choroid plexus

Front 174

The carotids bifurcate at what level?

Back 174

C3/C4

Front 175

Using an Inversion recovery sequence on a 1.5T magnet, what tissue is suppressed if the Inversion Time (TI/Tau) is 150?

Back 175

Fat

Front 176

If a sequence has a chain of 180 flip angles, it is referred to as a

Back 176

Fast spin echo/TSE

Front 177

Gradient moment nulling

Back 177

Reduces intra-voxel dephasing, is often called First Order motion comp, and is most effective on slow laminar flow

Front 178

A sequence which starts with a 180 pulse, then a 90 pulse, then a refocusing 180 pulse is referred to as a

Back 178

Inversion recovery sequence

Front 179

The main magnetic field is known as

Back 179

Bo

Front 180

In the following scenario, how many lines of K-space are filled with each repetition time? TR 3000| TE 80 | ETL 12 | slice thick 6mm | matrix 256x512 | NSA 1 | FOV 24cm

Back 180

12

Front 181

A word which is synonymous with fainting

Back 181

Syncope

Front 182

Difficulty walking

Back 182

Ataxia

Front 183

The colliculi are located in what area

Back 183

Posterior on the midbrain

Front 184

The colliculi are located in what area

Back 184

Posterior on the midbrain

Front 185

What is the effective TR in this cardiac gated scenario, in which the patient has the following factors? Heart rate 60 bpm; Trigger window 10%; Trigger delay 50 ms

Back 185

1000ms

Front 186

For a 1.5 Tesla scanner the difference in precessional frequency between fat and water is

Back 186

220 Hz

Front 187

When doing a 2dToF to show up the carotid arteries the pre-saturation band should be

Back 187

superior

Front 188

When imaging the inferior vena cava for flow the saturation band should be placed

Back 188

superior

Front 189

which artery is known for producing artifacts in the knee area

Back 189

popliteal artery

Front 190

Which plane best displays the genu, splenium, and the body of the corpus collosum?

Back 190

sagittal

Front 191

The Islets of Langerhans are located in what area

Back 191

Pancreas

Front 192

Non-living objects that may transmit pathogens (ie linens, telephones, and keyboards:)

Back 192

fomite

Front 193

In the event that a patient has a life-threatening MVA and is unable to give consent for surgery. This process is called

Back 193

Implied consent

Front 194

The adnexa is found in what area

Back 194

around the ovaries

Front 195

The best plane to display the median nerve

Back 195

axial

Front 196

The dural sinus which lies in closest proximity to the occipital and temporal lobes

Back 196

transverse sinus

Front 197

The dural sinus which lies closest to the pituitary gland

Back 197

cavernous sinus

Front 198

The omentum is located

Back 198

abdominal area

Front 199

When a patient becomes injured as the result of a negligent act that is extremely obvious, it is

Back 199

Res ipsa loquitor

Front 200

An animal that spreads disease from person to person

Back 200

vehicle

Front 201

The term respondeat superior indicates

Back 201

holds an employer liable for the acts of its employees

Front 202

The unlawful touching of the patient without consent is called

Back 202

battery

Front 203

The first confirmation of an exam request when a patient enters your department involves

Back 203

verify patient identification

Front 204

Verbally spreading confidential patient information is considered a violation of

Back 204

HIPPA

Front 205

A type of infection that occurs as the result of a patient being in the hospital is called

Back 205

nosocomial / hospital acquired

Front 206

Log rolling is a method of moving patients with a suspected

Back 206

vertebral column injury

Front 207

What type of isolation precautions should be used for HIV positive patients

Back 207

Standard/ universal

Front 208

The abbreviation that means biopsy is

Back 208

Bx