R 407 Final

Permanent magnets exhibit all of the following properties except:

Uses solenoid windings to produce a direction of current creating an electromagnet.

They are equipped with large discs of a ferromagnetic alloy such as neodymium, boron, and iron, or aluminum, nickel, and cobalt (ALNICO).

Does not require electrical power or cryogenic cooling.

The magnetic field is created by the inherent ferromagnetism of the alloy.
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Permanent magnets exhibit all of the following properties except:

Uses solenoid windings to produce a direction of current creating an electromagnet.

They are equipped with large discs of a ferromagnetic alloy such as neodymium, boron, and iron, or aluminum, nickel, and cobalt (ALNICO).

Does not require electrical power or cryogenic cooling.

The magnetic field is created by the inherent ferromagnetism of the alloy.
Uses solenoid windings to produce a direction of current creating an electromagnet.
A suddent loss of magnet superconductivity is known as:

Quench
MRI does not ever have a loss of magnet superconductivity
Helium Boil-off
Hydrogen Boil-off
Quench
The elevation of the T-wave in an EKG reading is known as:

Peripheral Nerve Stimulation
Magnetohydrodynamic Effect
Teratogenesis
Magnetophosphene Effect
Magnetohydrodynamic Effect
The total accumulated amount of energy that gets deposited in the body over time is known as:
The total accumulated amount of energy that gets deposited in the body over time is known as:

SAR
OID
SED
SID
SED
An MRI technologist is laying a patient on the table to prepare for an exam. The patient's bobbyepins fly out of her hair into the magnet and become stuck to the side. The object created a missile effect. What is the most likely magnetic property?

Diamagnetism
Paramagnetism
Superparamagnetism
Ferromagnetism
Ferromagnetism
What is used to reduce the missile effect from occurring?

Knowing where the 5 Gauss line is located
Active shielding
Passive shielding
Both active and passive shielding
Both active and passive shielding
(Choose all that apply)
Identify the objective symptoms indicating an air embolism may be occurring.

Dyspnea
Tachycardia
Hypotension
Cough
Dyspnea
Tachycardia
Hypotension
Cough
Coils of wire that alters the magnetic field strength in a linear fashion when a current is passed through them is known as:

Gradient
Static magnetic field
Gradient Echo Imaging
Time varying Radiofrequency field
Gradient
[Choose all that apply]
Identify the static field forces.

Torque Force
Lenz's Forces
Translational Force
Magnetic Forces
Torque Force
Lenz's Forces
Translational Force
A stainless-steel tank configured in the shape of a hollow cylinder that houses the helium reservoir is known as:

Cryogen
Basin
Cryostat
Quench pipe
Cryostat
What type of magnet uses a cryogen bath to reduce the amount of resistance in the electromagnet? Solenoid magnets Permanent magnets Superconducting magnets Resistive magnetsSuperconducting magnetsThe gradient magnetic field that is changing over time and is used to localize tissue is known as: The gradient magnetic field that is changing over time and is used to localize tissue is known as: Time-varying radiofrequency magnetic field Time-varying gradient magnetic field Gradient coils Gradient Echo ImagingGradient coils[Choose all that apply] Identify the ASTM international standard F2503-13 definitions for MRI signage. MR Conditional MR Compatible MR Unsafe MR SafeMR Conditional MR Unsafe MR SafeThe coils in the MRI system that allow the technologist to create coronal and sagittal plane imaging is known as: Parallel array Maxwell Phase array HelmholtzHelmholtzWhat 3 things are needed to create MR images? (choose 3) Coil Gradient Field Static Magnetic Field RF FieldGradient Field Static Magnetic Field RF FieldWhich of the following are risk factors for adverse IV Contrast reactions? Asthma Renal Insufficiency Renal Calculi Heart disease 3 & 4 1 & 2 1, 2, & 4 1, 3, &41, 2, & 4Iron, steel, and gadolinium (in its native state) are all examples of: Paramagnetism Diamagnetism Ferromagnetism SuperparamagnetismFerromagnetismWhat element is the main source used in cryogens? Helium Oxygen Carbon dioxide NitrogenHeliumWhat should be documented in the pregnant patient's medical record if contrast is deemed necessary? What should be documented in the pregnant patient's medical record if contrast is deemed necessary? The MRI exam can not be acquired without contrast. All are correct and should be documented There are not any other imaging modalities to utilize The examination cannot wait until post pregnancy.NOT The examination cannot wait until post pregnancy.All the following are results of the TVGM, EXCEPT. Peripheral Nerve Stimulation (PNS) Tissue Heating Vertigo, Nausea, and Nystagmus Acoustic or Auditory issuesNOT Vertigo, Nausea, and Nystagmus NOT Acoustic or Auditory issuesTo prevent burns padding can be used. The padding should be an insulating material that is recommended to be a thickness of ____. 1 mm 10 cm 1 cm 100 mm1 cm(Choose all that apply) Identify the properties of objects with Ferromagnetic properties. Large positive magnetic susceptibility with a large attraction to the external magnetic field Hydrogen, Helium, Gold, Silver, and Lead are examples Iron, Nickel, Cobalt, and Gadolinium (in its natural state) are examples Flux lines are distorted in the presence of this object. Retains magnetism when removed from the external magnetic field.Large positive magnetic susceptibility with a large attraction to the external magnetic field Iron, Nickel, Cobalt, and Gadolinium (in its natural state) are examples Flux lines are distorted in the presence of this object. Retains magnetism when removed from the external magnetic field.(True or False) To date, there have been studies showing mutagenic and/or teratogenesis effects on fetuses post GBCM.FalseThe acoustic noise heard during MRI scans is due to the Lenz's Law Magnetohydrodynamic Effect Lorentz force Magnetophosphene EffectNOT Lenz's LawThe IEC/FDA limit for Head SAR in normal mode is 10 W/kg 4 W/kg 3.2 W/kg 2 W/kg3.2 W/kgThis critical step is suggested by the ACR to help prevent significant extravasation. Talk with the patient to confirm if injection is going smoothly Monitor injection from the control room window Utilize a pulse oximeter Direct monitoringNOT Talk with the patient to confirm if injection is going smoothlyThis type of heat dissipation results in the heat moving away from the source (patient) during scans. Conduction Convection Evaporation RadiationConvection(Choose all that apply) A patient is showing moderate hives. Identify the treatment. Call 911 and start CPR Administer benadryl by mouth, intramuscular, OR through the IV. Monitor vitals Preserve the IV accessAdminister benadryl by mouth, intramuscular, OR through the IV. Monitor vitals Preserve the IV accessAccording to the ACR Manual on Contrast Media 2018, what is the recommended flow rate when using peripheral veins for venipuncture? > 5 ml/sec < 1 - 2 ml/sec 3 - 4 ml/sec< 1 - 2 ml/sec[Choose all that apply] Identify the hazards of a failed quench when the helium leaks into the MRI room. Ear drum rupture Asthma attack Frostbite HypothermiaEar drum rupture Asthma attack Frostbite Hypothermia(Choose all that apply) Identify the effects of the Magnetic Field strength increasing. Chemical shift increases SNR decreases Signal increases Noise increasesChemical shift increases Signal increases Noise increases[Choose all that apply] The most commonly used material to produce a permanent magnet is an alloy of: Aluminum Cobalt Steel NickelAluminum Cobalt Nickel[Choose all that apply] Identify the properties that affect Lenz's Force. The orientation of electrical conductor relative to the lines of magnetic force The static field and static field gradient The dimensions of the moving electrical conductor The speed of movement of the electrical conductor through the BoThe orientation of electrical conductor relative to the lines of magnetic force The static field and static field gradient The dimensions of the moving electrical conductor The speed of movement of the electrical conductor through the BoAn object that demonstrates a slight repulsion from the static magnetic field, such as water is known as Diamagnetism Paramagnetism Superparamagnetism FerromagnetismDiamagnetismA patient is laying on the table for an abdomen MRI. After the exam, a blister forms on the lateral side of the patient's left elbow. This is most likely a: Resonant burn Proximity burn Reflective burn Looping burnProximity burnPatients on dialysis and patients with acute kidney injury (AKI) are required to have an eGFR within 6 weeks of having MRI contrast. T/FFalse(Choose all that apply) Identify the treatment for venous air embolism. 100% oxygen If cardiopulmonary arrest, begin closed-chest CPR Place the patient in the left lateral decubitus position. Place the patient in the right lateral decubitus position100% oxygen If cardiopulmonary arrest, begin closed-chest CPR Place the patient in the left lateral decubitus position.What zone is the quench vent pipe when it is between the ceiling of the MRI room and exit point? zone 4 zone 1 zone 2 zone 3zone 3The cryostat's primary function is to prevent heat transfer from the adjacent system components to the cryogen. Match the following cryostat components to the corresponding function.The area that maintains the patient bore and other components of the MRI system that operates at room temperature. Warm Bore The material used to provide efficient heat shielding that prevents heat transfer by thermal radiation. It reduces the helium boil-off rate. Space Blanket Used to maintain refrigeration of the cryostat and prevent heat transfer by conduction. Chiller Used to exhaust boiled helium into the atmosphere safely. Quench PipePatients on hemodialysis must undergo treatment within what time period post-contrast administration? One week 2-3 days Immediately No longer than 24 hoursNo longer than 24 hoursAccording to the U.S. FDA, the sound pressure with hearing protection should be reduce to 99 dB B-weighting 85 dB B-weighting 120 dB A-weighting 99 dB A-weighting99 dB A-weightingA suddent loss of magnet superconductivity is known as: MRI does not ever have a loss of magnet superconductivity Helium Boil-off Hydrogen Boil-off QuenchQuench(Choose all that apply) What does the arrow of the Net Magnetic Vector (NMV) indicate? The longer the arrow, the higher the signal-to-noise ratio (SNR) The length indicates the field strength of the main magnetic field. The speed of the magnetic moments Direction of the main magnetic fieldThe longer the arrow, the higher the signal-to-noise ratio (SNR) The length indicates the field strength of the main magnetic field. Direction of the main magnetic fieldThis MRI system is commonly used for scanning large animals, humans with large body habitus, claustrophobic patients, etc. The sideways table movement allows for more convenient imaging of lateral body structures. These types of scanners use large permanent magnets or superconducting solenoids to generate the main magnetic field. Closed systems Open systems Extremity systemsOpen systemsWhile images are being obtained, your patient squeezes the alert ball. The sequence is paused/stopped, and you speak to the patient. They say they see flashes of light. Identify the true statements about their experience and the causes. The retina cells are experiencing a disturbance from the TVGM. The patient is experiencing magnetohydrodynamic effects. The patient is experiencing magnetophosphenes. TVGM induces circulating eddy currents in conductors within the body. This may cause stimulation in the nerves and muscle cells.The retina cells are experiencing a disturbance from the TVGM. The patient is experiencing magnetophosphenes. TVGM induces circulating eddy currents in conductors within the body. This may cause stimulation in the nerves and muscle cells.Thermal effects are due to Time-Varying Gradient Magnetic Fields Time-Varying Radiofrequency MF Static Magnetic Field 1 and 3 2 only 1 only 1 and 2NOT 1 and 2Nuclei that have a weak net magnetic vector and easily influenced by the static magnetic field is known as: Net magnetic vector Nuceli are not influenced by the magnet Spin-down Spin-upSpin-up[Choose all that apply] Identify the factors that affect the temperature increase in tissues: Type of RF pulse used The frequency of the radiation Electrical and geometrical tissue properties Repetition TimeType of RF pulse used The frequency of the radiation Electrical and geometrical tissue properties Repetition TimeWhich of the following factors help determine the GFR? Serum creatinine BUN Age Gender Race 1, 2, 4 1, 3, 4 3, 4, 5 All are usedAll are usedA process that causes birth defects or malformations in an embryo or fetus by an external agent is known as Magnetohydrodynamic Teratogenesis Nystagmus MagnetophospheneTeratogenesisTeratogenesis is a process that causes birth defects or malformations in an embryo or fetus by an external agent, such as an MRI examination. True FalseTrueThe force that causes ferromagnetic objects to align with the direction of the magnetic field is known as Rotational forces Translational forces Magnetic forces Lenz's forcesRotational forcesThe slew rate is measured in Gauss mT/m G/cm T/m/sT/m/sWhat is the hardware structure that houses the RF transmitter coil and the RF receiver coil? RF amplifiers MRI system RF coils RF speakersRF coilsWhich calculation represents the strongest translational force on an implant/object? Bo(dBo/dx) dBo/dT wo= Bo x lambda dB1/dxNOT dB1/dx Either Bo(dBo/dx) OR dBo/dTWhat temperature should gadolinium be kept prior to injection? 98.6 degrees Farenheit 0 degrees Celsius Room temperature 37 degrees CelsiusRoom temperatureAccording to the ACR Manual on Contrast Media, what catheter gauge is preferred for flow rates greater than 3 ml/sec? 20-gauge 18-gauge 12- gauge 16-gauge20-gaugeWhat happens to liquid helium if it reaches room temperature? It will change to a gaseous state Nothing will happen It will change to a solid state It will change to the element hydrogen.It will change to a gaseous state(Choose all that apply) Identify the organs responsible for eliminating the GBCM from the system. Kidneys Spleen Lung LiverLiver KidneysAll the following are true preventive methods for protecting patients from TVRF biological effects, EXCEPT: Assume all electrodes and ECG leads are MRI Safe or conditional Do not cross limbs where possible. All conductive leads should be placed in a linear fashion coming from the bore of the scanner.Assume all electrodes and ECG leads are MRI Safe or conditionalAll of the following are true about small coils, except: Small coverage area provides good SNR. Aliasing is more likely. Sensitive volume of the coil with be filled with tissue. The filling factor is low.The filling factor is low.All of the following are properties of the RF receive system except: The receiver coil detects noise. The receiver coil is responsible for the amplification, filtering, and digitization of analog signals. The signal is received by setting the factor TR. The receiver coil samples the signal directly.The signal is received by setting the factor TR.The time it takes the active gradient coil to reach its desired amplitude is known as: Maximum Gradient Strength Duty Cycle Rise time Slew RateRise time