Hardware control

Question 1

High field scanners typically have field strengths greater than or equal to:

Answer 1

1.5 Tesla

Question 2

Consistent room temperature of 65-75°F, humidity of 50-70%, and sufficient air flow in the MR scan room is recommended to

Answer 2

Make patients less vulnerable to the RF heating effects

Question 3

In a cross sectional view of the MR magnet design, which coils are closest to the patient?

Answer 3

Radiofrequency coils

Question 4

The liquid cryogens are cooled in a superconducting magnet at a temperature of

Answer 4

4° Kelvin

Question 5

Which of the following is NOT a magnetic field associated with MR imaging?

Answer 5

Gravitational earth magnetic fields

Question 6

The purpose of shimming the magnet is to

Answer 6

make the B0 field as homogenous as possible

Question 7

The array processor is responsible for:

Answer 7

Reconstructing the images using the Fourier transform

Question 8

: In order for energy to be efficiently transferred between a transmitter and receiver, the two must be at the same

Answer 8

Frequency

Question 9

The _____ is located within an equipment room.

Answer 9

RF power amplifier

Question 10

During a quench of the MR system, patients and employees should be evacuated from the scan room to avoid

A. Damage to tympanic membranes

B. Frostbite

C. Asphyxiation

D. All of the above

Answer 10

all of the above

Question 11

Field strength at magnet isocenter is measured in units of:

Answer 11

Tesla

Question 12

The unit of measurement of the magnetic field surrounding the periphery of the MR scanner is expressed as:

Answer 12

Gauss

Question 13

The intensity limit for a static magnetic field in clinical use is limited by the Food and Drug Administration (FDA) to _____________?

Answer 13

4 Tesla

Question 14

The patient image display with sequence parameter visualization is located in the

Answer 14

Scan control room

Question 15

The local RF coil used to image a human brain is typically located/kept in the __________.

Answer 15

Magnet room

Question 16

The CPU used to plot and adjust slices in an MR sequence is located:

Answer 16

Scan control room

Question 17

Radiofrequency (RF) shielding can be achieved by lining the scanner room walls with

Answer 17

Copper

Question 18

The location of the coils installed in the MRI scanner, from the inner point closest to the patient to the outer most edge, are

Answer 18

Radiofrequency coils, gradient coils, shim coils, main magnet

Question 19

The liquid cryogens most often used to maintain field strength in a super conducting MR system are:

Answer 19

Helium

Question 20

The coil construction in an MR system, from the innermost aspect to the outer:

Answer 20

Radiofrequency coils, gradient coils, shim coils, main magnet

Question 21

Doubling the magnetic field strength will:

Answer 21

Yield an increase of double the SNR

Question 22

: What type of magnet is used with most systems currently manufactured

Answer 22

Superconducting

Question 23

: Image 78 is an example of what type of MR scanner?

Answer 23

Open magnet

Question 24

Image 79 is an example of which MR system?

Answer 24

Superconducting magnet

Question 25

The direction of the magnetic field in Image 79 is:

Answer 25

Horizontal

Question 26

: Image 82 was acquired at what field strength?

Answer 26

1.5 Tesla

Question 27

Passive shielding can be accomplished by lining the MR room with ___________.

Answer 27

Steel

Question 28

Active shielding can be defined as:

Answer 28

Superconducting windings within the MR scanner, reducing the fringe magnetic field

Question 29

_________ would be used to contain the RF in an MR magnet room.

Answer 29

Copper

Question 30

___________ could be used to line the walls and/or floors of the MR magnet room to reduce the fringe field, and is defined as __________ shielding

Answer 30

Steel; passive