Final MRI

1)
Isotopes are atoms that gain or loose


Electrons

Neutrons

Protons

All of the above

2). MRI uses __________ waves.


Ultralow frequency

Radio frequency

Gamma

X-Rays

3) Ionizing radiation can potentially damage the


A) RNA

B) DNA

C) NAA

D) Cho

4). What is the substance that influences the most in the body weight?


Fat

minerals

water

Proteins

5). A 1.5 Tesla magnetic field is equal to:


150 gauss

1500 gauss

15,000 gauss

150,000 gauss

6). Enzymes are:


Proteins

Cholesterol

Phospholipids

Glycolipids

7). The hand right rule in electromagnetism indicates the direction of an induced magnetic field.
The thumb indicated the direction of the magnetic field, and the other four fingers indicate the direction of the moving charge particle (electrons),
0.71/0.71 Points

True

False
True False

8). Hertz is related to:


Distance

Frequency

Volume

Viscosity

10). For resonance to occur between two systems, they must have:


The same size

Same material

Same oscillating frequency

Same magnetic field

11). What is chemical shift?


Uneven magnetic field

Differences in hydrogen precessional frequency depending on molecular composition

Ability of a substance to become magnetize

All of the above

12). What is the precessional frequency of hydrogen in a 1.5T magnet? (Gyromagnetic ratio of hydrogen 42.6 MH)


42.6 MHz/T

63.8 MHz/T

127.8 MHz/T

21.3 MHz/T

13). Of the following radio-frequency pulse flip-angles, which is the smallest that will produce the maximum signal?


30 degree

60 degree

90 degree

180 degree

14). Hydrogen atoms in the body are ____________ oriented in absence of an applied external magnetic field.


Parallel

Antiparallel

Randomly

Perpendicular to each other

15) Which hydrogen atom will have the slowest frequency?


The one in Fat

The one in water

The one in Proteins

16). Extrinsic contrast parameters are those:


Can be manipulated by the MR technologist

Cannot be manipulated by the MR technologist

Are inherent to the body tissues

All of the above

17). What imaging parameters control image contrast?


FOV

Matrix

TE

TR

18). TR:


Is the time between each excitation pulse

Is the repetition time

Controls the amount of T1 recovery that is allowed to occur

All answers are correct

19). What is the Flip Angle used in Spin Echo pulse sequences?


90

360

180

45

20). Tissues that decay faster in the transverse plane have:


Long T1

Short T1

Long T2

Short T2

21). The image contrast obtained in a Proton Density (PD) weighted image depends on:


T1 relaxation time of the tissues

T2 relaxation times of the tissues

Amount of protons in the tissues

22). What parameters combination will you select in order to produce a T2* weighted images.


Long TR, short TE, and small flip angle

Long TR, long TE, and small flip angle

Long TR, long TE, and large flip angle

Short TR, long TE, and small flip angle

23)
The use of long TE will minimize T2 contrast in a PD weighted image


True

False
True False

24) Select the proper parameters to produce a T1WI in a GRE?


long TE

short FA

long FA

long TR

short TE

short TR

25). A spin echo image with a long TR and a short TE is known as what type of image?


T1 weighted image

Proton density weighted image

Susceptibility Weighted Image

T2 Weighted Image

26) FLAIR sequences use _______ inversion time.


2000

1000

500

175

27). Which of the following imaging parameters is the main responsible for the image contrast in an IR pulse sequence?


TR

TE

TI

28) Calculate the scan time in a FSE pulse sequence that has 3000 ms TR, 100 ms TE, 1 NEX, Matrix 256, 75% PES, 5 ETL, 150 ms TI.

2.8 Min

4.2 Min

2.6 Min

1.6 Min

30) The inversion recovery pulse sequence that is used to suppress CSF in proton density and T2 weighted images is known as what?


FISP

SSFR

FLAIR

STIR

31)
Dixon technique can be used to produce ____________ images.


Out phase imaging

Water suppression

Fat suppression

All answers are correct

32)
During out phase image acquisition, the dark signal intensity projected by the voxels where fat and water converge is the result of:


Magnetic suceptibility

Chemical miss-registration

Spatial missrepresentation

Spatial presaturation

33)
In which of the following examples, chemical saturation provides better image quality than STIR?


A 48 cm isocenter FOV

A 16 cm offcenter FOV

A 16 cm isocenter FOV

A 48 cm offcenter FOV

34). The main use of gradient echo pulse sequence is:


Detect pathologies

Reduce scan time

Improve image resolution

Increase SNR

35) Chemical saturation is more effective in _ T magnet


1

1.5

3

36) On a 2D image acquisition: What will be the scan time using the following parameters: TR 500 ms, TE 20 ms, PES 256, FES 512, slice thickness 5 mm, NEX 2?


256 s

200000 ms

25.6 s

2560 000 ms

37). Which Parameter(s) affect total scan time?


Repetition time

Number of phase encoding steps

Number of excitations

All of the above

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


Sequential

2D volumetric

3D volumetric

39) Using the following protocol, determine the scan time for this pulse sequence: (round off your answer to the nearest minute.)
FOV: 320mm, TR: 2000ms, TE 20/80ms, NEX: 1, Matrix: 256x128


3 minf

4 mins

6 mins

12 mins

40) What will be the scan time for a pulse sequence that has 500 ms TR, 20 ms TE, 256 frequency encoding steps, 128 phase encoding steps, 1 number of excitation?


64 s

32000 ms

64000 s

128000 ms

41) Which gradient will be used as Frequency encoding on a sagittal image of the spine?


X

Y

Z

B

42) Which gradients could be used for phase encoding in sagittal image?


Y or Z

X or Z

X or Y

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


Z gradient

Y gradient

X gradient

44) Which gradient will make the precessional frequency of the magnetization of protons in the patient left eye different than the patient's right heel?


X

Y

Z

X,Y and Z

45) In a horizontal field magnet, what is the primary slice select gradient for an Axial Slice?


Gx

Gz

Gy

46) When image matrix is increased, spatial resolution______


Increases

Stays the same

Decreases

47). Which of the following parameters combination will produce an image with less resolution?


Slice thickness 3 mm, matrix 192 X 256, FOV 48 cm.

Slice thickness 3 mm, matrix 192 X 256, FOV 24 cm.

Slice thickness 6 mm, matrix 192 X 256, FOV 48 cm.

Slice thickness 3 mm, matrix 192 X 192, FOV 24 cm.

48) When image matrix is increased, scan time______


Increases

Decreases

Stays the same

49) With similar imaging parameters, what is the weighted image with lower SNR?


T1

T2

PD

T2*

50) Which of the following will better describe a fine matrix?


With low number of frequency encoding and phase encoding and results in large pixels in the FOV

With high number of frequency encoding and phase encoding and results in small pixels in the FOV

With more number of phases encoding steps compare to frequency encoding steps and results in rectangular pixels

With the same number of phase encoding steps and frequency encoding steps and results in square pixels

51) Using 1 NEX combined with half Fourier will produce a decrease of the SNR to an approximately:


25%

50%

70%

80%

52) When slice spacing increases in a sequential acquisition, anatomical coverage ______


Decreases

Increases

It is not affected

53) Doubling the matrix and FOV will result on:


SNR increases 141%

SNR decreases to 35.25%

SNR decreases to 25%

SNR stays the same

54) For the following spin-echo protocol:
FOV: 320/ TR:500/ TE:25/ SliceThick.:5mm/ Slice Gap:1mm/ Slice.#:9/ NEX:4, Matrix:192
Increasing FOV, TE and Slice Interval will:


Increase scan time.

Decrease scan time.

Not affect scan time.

55). For the following spin-echo protocol:
FOV: 320/ TR:500/ TE:25/ SliceThick.:5mm/ Slice Gap:1mm/ Slice.#:9/ NEX:4, Matrix:192
Decreasing TE will


Decrease the # of allowable slices.

Increase the # of allowable slices.

Increase scan time.

Decrease scan time.

56) Which parameter combination will result in higher partial volume?


FOV 20 Matrix 256 Slice Thickness 5

FOV 20 Matrix 256 Slice Thickness 10

FOV 20 Matrix 512 Slice Thickness 5

FOV 10 Matrix 256 Slice Thickness 5

58) Cross talk and cross excitation can be reduced by:


Increasing FOV

Using anti-aliasing technique

Using gaps between the slices

Decreasing the TE

60) Cross talk will result in slices with


Different resolution

Different SNR

Different scan time

Different image weighted

Can the perfusion be positive (show penumbra) if the DWI is negative?


YES

NO

66). What is the unit use to measure chemical shift?


Hz

ppm

Hz/s

67) Clinical Applications of fMRI include


Surgery planning

Epilepsy

Strokes

All answers are correct

71) The maximum exposure to the head and trunk from the main magnetic field (Bo) is:


2T

8T

4T

5T

72) The attractive force that an object will experience at a distance of 6 feet from isocenter of the magnet is dependent on:


The ferromagnetic properties of the object

The mass of the object

The field strength of the system

All of the above

73). Ancillary equipment that should be included in an MRI department includes which of the following?


Non-ferrous wheelchair or stretcher

Proper monitoring equipment for sedated patients

A crash cart for emergency situations

All of the above

74) The best way to lessen the effects of acoustic noise during an MRI study is to:


Turn off the gradient power supply.

Offer the patient disposable ear plugs.

Offer the patient a blind fold.

Talk to the patient throughout the MRI study.

Hazards to patients and technologists due to ferromagnetic objects within the scan room include which of the following?


Metal projectiles

Tissue burns

Image artifacts

None of the above

76) Who is the responsible person for approving of the patient safety questionnaire?


Ordering physician

MR Technologist

Patient nurse

MR Physicist

77) What would you do in the following situation:
A patient walks in to have an MRI of the chest done. The patient claims not sure of having a heart valve implanted 2 years ago but brings a chest x-ray done earlier that day.


Go ahead and review the chest x-ray and if clear proceed with the MRI

Go ahead scan the patient, all heart valves are safe after 6 weeks

Send the patient home and ask him to bring information card

Send the chest x-ray to the radiologist for clearance

78) Passed through a strong magnetic field, some implanted and ferromagnetic devices such as neuro-aneurysm clips, suture material, and surgical clips may experience the force of:


inertia

torque

acceleration

deceleration

79) Once a patient has been screened, positioned, and the MRI study is under way, the MRI Technologist should:


Monitor the patient throughout the MRI study visually and by using the patient intercom.

Leave the MRI area to perform other related duties.

Turn off the patient intercom to avoid hearing the knocking sounds.

Leave a MRI clinical student in charge of the patient.

80) Prior entering the MRI environment all patients and individuals must be screened:


Verbally

Written

Verbally and Written

Physically

Who approves the discharge of a patient after an IV contras extravasations?


MR Technologist

Physician

Nurse

MRI safety officer

82) Which of the following is most likely to produce an allergic reaction?


an ionic IV contrast agent

a non-ionic IV contrast agent

plasma

all of the above

NSF is a medical condition very related to the use of gadolinium contrast agent. NSF stands for:

Neurologic systemic fibrosis

Nephrogenic systolic fibrosis

Nephrogenic systemic fibrosis

Nephrogenic fibrosing dermopathy

Which of the following characteristics of an IV contrast agent affects patient tolerance?
1. injection rate
2. osmolality
3. dose


1 only

2 only

3 only

1, 2 & 3

85) As a MRI technologist, which of the following parts of the patient’s history would be important for you to document:


possibility of pregnancy

allergies to medications including contrast media

past surgeries

all of the above

87) Which type of MRI magnet is made up of naturally ferromagnetic material?


superconductive

resistive

permanent

88) Shiller units are used to:


Reduce the fringe field

Maintain magnetic temperature low

Reduce RF interference

Improve magnetic homogeneity

89) High field magnets are considered to be in a range of:


0.5 to 1.4 T

4.0 to 8.0 T

1.5 to 3.0 T

90) What is the main source of magnetic field in homogeneities?


Eddy currents

RF leak

Differences in precessional frequency between hydrogen atoms.

91) Which type of receiver radio-frequency coil is placed close to a patient's body for the purpose of imaging superficial anatomic structures?


Solenoid coils.

Maxwell coils.

Surface coils.

Golay coils.

Quadrature coil can provide a 50% improvement in signal-to-noise ratio (SNR) when used to receive the MR signal.

True
False
True False

93) In a 1.5 T magnet the receiver coil must be set at an approximately ______ MHz/T.


42.6

21.3

63.8

85.2

94) Array coils:


Use one coil to gather the imaging data

Are receive only coils

Use more than one coil to gather imaging data simultaneously

The magnetic fields involved in MRI are:
1-the static magnetic field
2-time-varying magnetic field
3-radio frequencies field
4-microwave field


1,2, and 3

1 and 4

1 and 2

1,2,3 and 4

Conductive copper windings that alter the main magnetic field along a strict coordinate are known as which of the following?

Surface coils

Gradients coils

Interference coils

Shim coils

97). Gradient coils are best described as which of the following?


Independent electromagnets that switch on and off

Useful for field service engineers when ramping up a magnetic field

Shim coils that correct for homogeneity

Devices placed on or near the region of interest to be imaged before scanning

Which of the following is NOT an advantage of permanent magnets?


low operating cost

Small fringe fileds

No power supply requeriments

Quick turn off capability

Which of the following is a unit of measurement for the strength or peak amplitude of a gradient magnetic field?


Parts per million (ppm)

Milliseconds (ms)

Millitesla per meter (mT/m)

Angstrom units (au)

Which of the following is NOT an advantage of permanent magnets?


No power supply requeriments

Quick turn off capability

Small fringe fileds

low operating cost

101) What image will result from the following description?
1. The coverage must include the entire eyeball from inferior to superior.
2. The FOV should include the optic chiasm posteriorly and the eyeball anterior.
3. Slices should be aligned parallel to both optic nerves.


Coronal IAC

Coronal orbits

Sagittal pituitary

Axial orbits

102) Sagittal images of the brain should:


Be positioned perpendicular to the CA-PC line

Be aligned parallel to the longitudinal fissure of the brain on the axial and coronal images.

Cover the whole brain from side to side

Be positioned parallel to the AC-PC line

103) What protocol would you use on a patient that has an MRI of the brain order looking for a vestibular schwannoma?


Brain Sella

Brain Temporal lobe

Brain IAC

Brain Orbits

What would be the best slice position and order (direction) when performing a TOF-MRA of the intracranial circulation?


Head to foot

Axial

Sagittal

Coronal

Foot to head

Anterior to posterior

106) What pulse sequence is the best to detect an acute ischemic event in the brain?


STIR

DWI

SWI

FLAIR

107) What should be the area of coverage when performing a TOF-MRA of the intracranial and extracranial circulation?


Corpus callosum to foramen magnum

Corpus callosum to C3-4 approximately

Foramen magnum to C3-4 approximately

Corpus callosum to artic arch

109) What pulse sequence is the best to detect an acute ischemic event in the brain?


STIR

DWI

FLAIR

SWI

110) What can be done to reduce flow artifacts in axial images of the neck?


Larger FOV

No-phase wrap

Superior and inferior saturation bands

Phase in the left to right direction

112) Using a sagittal image, the axial slices of the spine should be positioned parallel to the _____________ or perpendicular to the __________.

Spinal cord / intervertebral disk

intervertebral disc / spinal cord

spinal cord / transverse foramina

intervertebral disc / transverse foramina

114) Which body plane corresponds to the short axis plane of the forefoot?


Axial

Sagittal

Coronal

120) Which area would you scan for a proximal biceps tendon tear?


Shoulder

Elbow

Forearm

Wrist

137) What blood vessel arises directly from the aortic arch?


LT CCA

LT Subclavian A.

RT CCA

RT Subclavian A.