Frage 1
Frage
Which of the following is an advantage of a permanent magnet MRI system
Antworten
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Very heavy
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Low operating costs
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Fixed field strength
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Limited field strength
Frage 2
Frage
Which of the following types of MRI magnet is known as the Classical electromagnet
Antworten
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Resistive magnet
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Superconducting magnet
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Permanent magnet
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Distractive magnet
Frage 3
Frage
Which of the following is a disadvantage of a resistive magnet MRI system
Antworten
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Easy coil maintenance
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Low cost
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High power consumption
-
None of the above
Frage 4
Frage
The type of MRI magnet that is produced by cooling a current down to 4 degrees Kelvin is known as a
Antworten
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Distractive magnet
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Permanent magnet
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Resistive magnet
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Superconducting magnet
Frage 5
Frage
The type of MRI magnet that allows the highest field strengths is a
Antworten
-
Resistive magnet
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Superconducting magnet
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Iron core magnet
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Permanent magnet
Frage 6
Frage
Coils used to correct imperfections in the magnetic field are known as
Antworten
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RF coils
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Surface coils
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Gradient coils
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Shim coils
Frage 7
Frage
The type of magnet that is produced by permanently magnetizing a ferromagnetic substance is known as a
Antworten
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Resistive magnet
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Electromagnet
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Superconducting magnet
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Permanent magnet
Frage 8
Frage
In clinical MRI, permanent magnets can be produced to operate up to what field strength
Antworten
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0.3 tesla
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0.5 tesla
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1.0 tesla
-
1.5 tesla
Frage 9
Frage
Which of the following is a disadvantage of using a permanent magnet in clinical MRI
Frage 10
Frage
Which of the following materials is most commonly used to produce a permanent magnet
Frage 11
Frage
The type of magnet that is produced by passing an electrical current through a conductor is known as a
Frage 12
Frage
The rule that is used to determine the direction of the magnetic field in an electromagnet is known as
Antworten
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Ohm's Law
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Right hand thumb rule
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Left hand thumb rule
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None of the above
Frage 13
Frage
In clinical MRI, resistive magnets usually operate at what field strength
Frage 14
Frage
Which of the following is an advantage of using a resistive magnet for clinical MRI
Antworten
-
High power consumption
-
Low capital cost
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Low field strength
-
None of the above
Frage 15
Frage
The law that is used to determine the amount of resistance in a conductor is known as
Antworten
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Newton's Law
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Ohm's Law
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Faraday's Law
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Murphy's Law
Frage 16
Frage
The type o f magnet that is produced by removing resistance from a conductive wire is known as
Antworten
-
Resistive magnet
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Reactive magnet
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Permanent magnet
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Superconducting magnet
Frage 17
Frage
The wire used to create the main magnetic field in a superconducting magnet is known as
Antworten
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Aluminum-Tiobium
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Iron sulfite
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Copper-tungsten
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Niobium-Titanium
Frage 18
Frage
The external magnetic field in a superconducting magnet is said to be what type of magnetic field
Antworten
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Static
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Kinetic
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Gradient
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Resistive
Frage 19
Frage
The wire used in the main magnetic field of a superconducting magnet has its resistance removed by cooling it to a temperature of
Antworten
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-452 degrees Fahrenheit
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0 degrees Celsius
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269 degrees Kelvin
-
None of the above
Frage 20
Frage
The liquids used to cool the wire in the main magnetic field of a superconducting magnet are known as
Antworten
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Neon gases
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Plasma
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Cryogens
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None of the above
Frage 21
Frage
The specific liquids used to maintain low temperatures in the superconducting wire are
Antworten
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Titanium and Niobium
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Hydrogen and Neon
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Halon and Oxygen
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Helium and Nitrogen
Frage 22
Frage
The device used to store and transport cryogenic liquids is known as a
Antworten
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Thermos
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Dewar
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Barrel
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None of the above
Frage 23
Frage
In a superconducting magnet, the sudden loss of superconductivity is known as a
Antworten
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Squelch
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Slouch
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Screech
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Quench
Frage 24
Frage
In an MRI system, the magnetic field that extends outside the bore of the magnet is known as the
Antworten
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Extended field
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Outer field
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Fringe field
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In field
Frage 25
Frage
In clinical MRI, superconducting magnets usually operate at field strengths from
Antworten
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0.15 to 0.3 tesla
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0.5 to 2.0 tesla
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2.5 to 4.0 tesla
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Over 4 tesla
Frage 26
Frage
In clinical MRI, which of the following is an advantage of using a superconducting magnet
Antworten
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High field strength
-
Shorter scan times
-
Low power consumption
-
All of the above
Frage 27
Frage
In clinical MRI, which of the following is a disadvantage of using a superconducting magnet
Antworten
-
High capital costs
-
High fringe field
-
High cryogenic costs
-
All of the above
Frage 28
Frage
The method used to contain the main magnetic field within the scan room is known as
Antworten
-
Shimming
-
Shielding
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Fringing
-
None of the above
Frage 29
Frage
The method of MRI field containment that uses steel lining in the walls of the magnetic room is known as
Antworten
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Active shimming
-
Passive shielding
-
Active shielding
-
Passive shimming
Frage 30
Frage
The method of MRI field containment that uses additional magnets outside the cryogenic area of the magnet is known as
Antworten
-
Active shimming
-
Passive shielding
-
Active shielding
-
Passive shimming
Frage 31
Frage
The process of adjusting coils to improve the homogeneity of the external magnetic field is known as
Antworten
-
Strengthening
-
Fringing
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Shielding
-
Shimming
Frage 32
Frage
Each shim coil requires its own power supply
Frage 33
Frage
The type of shimming that is achieved by placing a ferrous material around the main magnet is known as
Antworten
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Passive shimming
-
Passive shielding
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Active shimming
-
Active shielding
Frage 34
Frage
The type of shimming that is achieved by adjusting the electrical current in specialized coils is known as
Antworten
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Passive shimming
-
Passive shielding
-
Active shimming
-
Active shielding
Frage 35
Frage
The homogeneity of the external magnetic field is measured in what type of unit
Antworten
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Tesla per cm
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Part per million (ppm)
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Gauss per meter
-
Megahertz
Frage 36
Frage
In clinical MRI, the homogeneity of the magnet should be at least
Antworten
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1 tesla per cm
-
10 parts per million
-
0.5 gauss per meter
-
32 magahertz
Frage 37
Frage
The type of coils used to change the strength of the magnetic field inside the bore of the magnet are known as
Antworten
-
RF coils
-
Shim coils
-
Surface coils
-
Gradient coils
Frage 38
Frage
In a gradient coil, the amplitude of the gradient slope is determined by what factor
Frage 39
Frage
How many gradient coils are there in a clinical MRI system
Antworten
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1 pair
-
2 pairs
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3 pairs
-
4 pairs
Frage 40
Frage
Gradient strength is measured in what form of unit
Frage 41
Frage
The time it takes for a gradient coil to reach its peak strength is known as
its
Antworten
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Repetition time
-
Echo time
-
Rise time
-
Inversion time
Frage 42
Frage
Coils that are used to transmit and receive radio frequencies are known as
Antworten
-
RF coils
-
Shim coils
-
Gradient coils
-
Surface coils
Frage 43
Frage
The type of RF coil that encompasses the entire anatomy to be scanned is known as
Antworten
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Surface coil
-
Phased array coil
-
Volume coil
-
Gradient coil
Frage 44
Frage
The type of RF coil configuration that uses a pair of coils perpendicular to each other to transmit and receive signal is known as a
Antworten
-
Surface coil
-
Phased array coil
-
Quadrature coil
-
Shim coil
Frage 45
Frage
The type of RF coil configuration that uses a series of independent coils to create one image is known as a
Antworten
-
Surface coil
-
Phased array coil
-
Quadrature coil
-
Gradient coil
Frage 46
Frage
The type of RF coil configuration that is used to image anatomical structures close to the surface of the patient is known as a
Antworten
-
Surface coil
-
Quadrature coil
-
Phased array coil
-
Shim coil
Frage 47
Frage
Mutual induction between the RF transmitter and the RF receiver is known
as
Antworten
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Isolation
-
Deisolation
-
Coupling
-
Decoupling
Frage 48
Frage
Isolating the RF transmitter from the RF receiver is known as
Antworten
-
Deisolation
-
Isolation
-
Coupling
-
Decoupling
Frage 49
Frage
The computer that performs the complex calculations necessary to reconstruct MRI images is known as the
Antworten
-
Array processor
-
RF amplifier
-
Gradient amplifier
-
Shim cabinet
Frage 50
Frage
The device in the MRI system that supplies power to the gradient coils is known as the
Antworten
-
Array processor
-
RF amplifier
-
Gradient amplifier
-
None of the above
Frage 51
Frage
The device in the MRI system that supplies power to the RF transmitter coils is known as the
Antworten
-
Array processor
-
RF amplifier
-
Gradient amplifier
-
None of the above
Frage 52
Frage
Prior to each scan, the process of prescanning performs which type of calibration
Antworten
-
Adjusts the transmit gain
-
Adjusts the receive attenuation
-
Sets the center frequency
-
All of the above
Frage 53
Frage
The calibration of transmit gain during the prescan process determines which factor
Antworten
-
RF output necessary to produce a 90 degree flip angle
-
The exact resonant frequency
-
The necessary amount of signal needed to create an image
-
None of the above
Frage 54
Frage
The process during the prescan that determines the amount of signal that is received is known as
Frage 55
Frage
The process during prescan that fine tunes the resonant frequency is known
as
Frage 56
Frage
How many miliseconds are there in a minute