MRI Safety Practice Questions

What is the primary reason for MRI safety precautions?

a) To enhance image quality

b) To protect patients and personnel

c) To speed up scanning procedures

d) To increase scanner efficiency

b) To protect patients and personnel

Which of the following is a unit used to measure magnetic field strength?

a) Hertz

b) Tesla

c) Watt

d) Joule

b) Tesla

What is the fringe field in MRI?

a) The outer surface of the MRI machine

b) The stray magnetic field around the magnet

c) A noise-reduction system

d) An insulating layer

b) The stray magnetic field around the magnet

Which of these items is considered a potential projectile in MRI?

a) Paper clip

b) Wooden pen

c) Plastic bottle

a) Paper clip

What is the term for ferromagnetic objects being attracted to the MRI scanner?

a) Fringe effect

b) Projectile effect

c) Resonance effect

d) Scatter effect

b) Projectile effect

Which materials are ferromagnetic and must be avoided near the MRI scanner?

a) Gold and silver

b) Iron, cobalt, and nickel

c) Aluminum and copper

d) Plastic and rubber

b) Iron, cobalt, and nickel

What is the "missile effect" in MRI safety?

a) The scanner moving suddenly during operation

b) A ferromagnetic object accelerating into the magnet

c) Equipment failure in the scanner room

d) A patient moving too quickly in the bore

b) A ferromagnetic object accelerating into the magnet

What should be used to identify ferromagnetic objects before entering the MRI scanner room?

a) Metal detector

b) Ferromagnetic detection system

c) X-ray scanner

d) Ultrasound

b) Ferromagnetic detection system

Which MRI safety zone is accessible to the general public without restrictions?

a) Zone 4

b) Zone 3

c) Zone 2

d) Zone 1

d) Zone 1

What is the primary function of Zone 2 in the MRI suite?

a) Patient preparation and screening

b) MRI scanning

c) Equipment storage

d) Emergency exits

a) Patient preparation and screening

Who is responsible for supervising non-MR personnel in Zone 4?

a) Level 1 MR personnel

b) Level 2 MR personnel

c) Hospital security

d) General radiology staff

b) Level 2 MR personnel

What is the maximum field strength considered safe for the general public in an

MRI setting?

a) 5 Gauss

b) 15 Gauss

c) 0.5 Tesla

d) 10 Tesla

a) 5 Gauss

Which of the following is NOT a hazard of RF energy in MRI?

a) Whole-body diffuse heating

b) Peripheral nerve stimulation

c) Local burns

d) Heating of metallic object

b) Peripheral nerve stimulation

What causes peripheral nerve stimulation (PNS) in MRI?

a) Static magnetic field

b) Gradient magnetic field

c) Radiofrequency energy

d) Cryogens in the system

b) Gradient magnetic field

How proximity burns in MRI are typically caused?

a) Skin touching the magnet bore directly

b) Improper gradient settings

c) Overexposure to RF pulses

d) Contact with non-metallic objects

a) Skin touching the magnet bore directly

What should be done to avoid burns caused by RF energy?

a) Insulate cables and avoid loops

b) Decrease the gradient strength

c) Increase the fan speed in the room

d) Lower the field strength

a) Insulate cables and avoid loops

What is a quench in MRI?

a) Cooling of the magnet

b) Emergency shutdown of the magnetic field

c) Increasing the magnetic field for stronger imaging

d) Releasing RF energy to the patient

b) Emergency shutdown of the magnetic field

What is the primary hazard during a magnet quench if vent systems fail?

a) Electrocution

b) Asphyxiation and frostbite

c) Equipment failure

d) Burns

b) Asphyxiation and frostbite

When should the magnet be quenched intentionally?

a) During a routine maintenance procedure

b) If a patient is pinned by a ferromagnetic object

c) When the scanner overheats

d) During a power outage

b) If a patient is pinned by a ferromagnetic object

What does the "Electrical Emergency Power Off" button NOT do?

a) Stops power to the magnet room

b) Removes the static magnetic field

c) Prevents sparking or overheating

d) Shuts down all electrical component

b) Removes the static magnetic field

Which label indicates an object is completely non-metallic and safe for the MRI

environment?

a) MR Unsafe

b) MR Conditional

c) MR Safe

c) MR Safe

What type of device is used to scan for ferromagnetic items on a patient?

a) Stationary FMDS

b) Handheld FMDS

c) Handheld X-ray device

d) Metal detector

b) Handheld FMDS

What is the 5 Gauss line?

a) The point where RF waves are strongest

b) The safety boundary for ferromagnetic objects

c) A threshold for imaging clarity

d) The magnetic field level required for operation

b) The safety boundary for ferromagnetic objects

What must all patients and non-MR personnel complete before entering Zone 3?

a) A radiation exposure form

b) A metal sensitivity test

c) An MRI safety screening form

d) A medical history update

c) An MRI safety screening form

What is Lenz’s force in MRI?

a) The force opposing the movement of non-ferromagnetic conductors

b) A force that increases RF wave efficiency

c) A side effect of gradient switching

d) A measurement of static field strength

a) The force opposing the movement of non-ferromagnetic conductors

What clothing should patients wear in the MRI scanner?

a) Their own clothing

b) Site-supplied MR Safe gowns

c) Clothing with antimicrobial fibers

d) Hospital scrubs

b) Site-supplied MR Safe gowns

What is a common countermeasure for claustrophobia in MRI patients?

a) Using sedation for all scans

b) Allowing a friend or relative in the scan room

c) Reducing the scanning time to 5 minutes

d) Increasing magnet strength

b) Allowing a friend or relative in the scan room

What is a common reaction to gadolinium-based contrast agents?

a) Nausea and vomiting

b) Severe burns

c) Loss of vision

d) Peripheral nerve stimulation

a) Nausea and vomiting

What precaution is taken for pregnant healthcare practitioners working in MRI?

a) Avoiding Zone 1 access

b) Working in the MR environment is permitted with restrictions

c) They must avoid all patient interactions

d) Immediate removal from the workplace

b) Working in the MR environment is permitted with restrictions

Which stage of pregnancy has shown no conclusive harm from MRI exposure to the

fetus?

a) First trimester only

b) All stages of pregnancy

c) Third trimester only

d) MRI is unsafe in all stages

b) All stages of pregnancy

What should be done to prevent hearing damage from MRI noise?

a) Use earplugs or headphones with a noise reduction rating

b) Increase the gradient field speed

c) Limit the scan duration to 15 minutes

d) Lower the magnetic field strength

a) Use earplugs or headphones with a noise reduction rating

Why must patients avoid crossing their legs or clasping their hands during an MRI

scan?

a) It disrupts the scan's magnetic field

b) To avoid forming conductive loops

c) It increases image resolution

d) To prevent nerve stimulation

b) To avoid forming conductive loops

What is the primary hazard associated with laser light during patient landmarking?

a) Severe burns

b) Eye damage

c) Overheating of equipment

d) Interference with RF signals

b) Eye damage

Why are conventional metal detectors not recommended for MRI safety screening?

a) They cannot detect ferromagnetic objects specifically

b) They are too slow to operate

c) They emit RF energy

d) They require calibration before use

a) They cannot detect ferromagnetic objects specifically

A 1.5T MRI scanner has a field strength equivalent to:

a. 10,000 Gauss

b. 15,000 Gauss

c. 20,000 Gauss

d. 25,000 Gauss

b. 15,000 Gauss

The fringe field is:

a. An extension of the magnetic field emanating from isocenter

b. Stray magnetic fields additional to the main magnetic field

c. An invisible field that causes inhomogeneity

d. None of these

a. An extension of the magnetic field emanating from isocenter

The most serious safety concern pertaining to the main magnetic field is:

a. Projectiles

b. Implant safety

c. Patient care

d. Contrast injection reactions

a. Projectiles

Zone 1 is open to:

a. The general public

b. Supervised patients

c. Level 1 MR Personnel supervised by Level 2 MR Personnel

d. No one because it must remain closed except when it must be open for screened

patients to enter.

a. The general public

Zone 2 is open to:

a. The general public

b. Supervised patients

c. Level 1 MR Personnel supervised by Level 2 MR Personnel

d. No one because it must remain closed except when it must be open for screened patients to enters

b. Supervised patients

Zone 3 is open to:

a. The general public

b. Supervised patients

c. Level 1 MR Personnel supervised by Level 2 MR Personnel

d. No one because it must remain closed except when it must be open for screened patients to enter

c. Level 1 MR Personnel supervised by Level 2 MR Personnel

Zone 4 is open to:

a. The general public

b. Supervised patients

c. Level 1 MR Personnel supervised by Level 2 MR Personnel

d. No one because it must remain closed except when it must be open for screened patients to enter

d. No one because it must remain closed except when it must be open for screened patients to enter

Magnetophospenes are:

a. Flashes of light caused by current induction in the retina

b. Nerve stimulation in the peripheral nervous system

c. Induced current on the surface of skin

d. Focused heating of metallic objects in the bod

a. Flashes of light caused by current induction in the retina

PNS is caused by:

a. Flashes of light caused by current induction in the retina

b. Nerve stimulation in the peripheral nervous system

c. Induced current on the surface of skin

d. Focused heating of metallic objects in the bod

b. Nerve stimulation in the peripheral nervous system

Lenz’s force states:

a. Faraday’s law is incorrect

b. A secondary induced magnetic field strengthens the original magnetic field

c. A secondary induced magnetic field opposes the original magnetic field

d. A secondary induced magnetic field enhances the effects of the original magnetic field

c. A secondary induced magnetic field opposes the original magnetic field

Energy deposition by an RF pulse can cause:

a. Diffuse heating throughout the whole body

b. Focused heating of a tattoo

c. Heating of an implant

d. All of these can occur

d. All of these can occur

Drug-delivery patches must be removed prior to a scan due to:

a. Unintended drug interactions with the main magnetic field

b. The metallic foil heating up due to RF energy deposition

c. Skin irritation caused by the patch during a scan

d. The metallic foil heating up due to gradient magnetic field fluctuations

b. The metallic foil heating up due to RF energy deposition

When a quench is eminent, which of the following is of concern:

a. Frostbite

b. Asphyxiation

c. Rupturing of ear drums

d. All of these

d. All of these

Gadolinium chelates are:

a. Diamagnetic

b. Paramagnetic

c. Superparamagnetic

d. Ferromagnetic

c. Superparamagnetic

Pure gadolinium is:

a. Diamagnetic

b. Paramagnetic

c. Superparamagnetic

d. Ferromagnetic

d. Ferromagnetic

The likelihood of NSF is increased in patients with:

a. A history of chronic kidney disease

b. A history of arthritis

c. High blood pressure

d. High eGFR lab values

a. A history of chronic kidney disease

Concerns pertaining to hearing loss are associated with the use of:

a. RF pulses

b. Static Magnetic field

c. Gradients

d. Shim coils

c. Gradients

Antenna effect is increased due to:

a. Non-standard implant sizes

b. Increased implant length

c. Placement of implants

d. Increasing field strengths

b. Increased implant length

Elevated voltages in blood streams are caused by:

a. Magnetohydrodynamic effects

b. RF energy deposition

c. Peripheral nerve stimulation

d. Magnetophosphenes

a. Magnetohydrodynamic effects

In preparation for the MRI examination, patients should be encouraged to:

a. Wear their own clothing so as to feel “at home” with the study

b. Wear a wrist watch so they are aware of the length of the exam

c. Keep their hearing aid in so as to hear the commands and requests of the technologist

d. Change into a hospital gown or a scrub suit provided by the imaging center and known to be MR safe (containing no metallic components such as snaps and/or zippers)

d. Change into a hospital gown or a scrub suit provided by the imaging center and known to be MR safe (containing no metallic components such as snaps and/or zippers)

Persons that should be educated about the effects of the static magnetic field, especially in high field superconducting magnets, include:

I. The nursing staff and the code team

II. The housekeeping staff and members of the fire department

III. The anesthesiologists and respiratory therapists

IV. The technologist and the radiologist

a. IV only

b. I and IV only

c. I, III, and IV only

d. I, II, III, and IV

d. I, II, III, and IV

Persons are identified into “levels” whereby “Level 2” personnel include:

a. Persons with no MRI safety training

b. Persons with limited MRI safety training

c. Persons with extensive training in MRI safety to include the broader aspects of MRI (such as the magnetic field, gradient and RF fields – to name a few)

d. There are no Level 2 personnel in MRI safety

c. Persons with extensive training in MRI safety to include the broader aspects of MRI (such as the magnetic field, gradient and RF fields – to name a few)

Absolute contraindications to MRI include:

a. Intracranial vascular clips, unless they are KNOWN to be safe

b. Cardiac pacemakers, unless they are KNOWN to be safe

c. Pregnancy

d. Intraocular, ferrous foreign bodies

d. Intraocular, ferrous foreign bodies

The accepted standard of care for the detection of intraocular ferrous foreign bodies is:

a. CT

b. MRI

c. Plain film

d. Visual exam

c. Plain film

Before a patient enters the MRI environment they should be screened for:

a. Prior injuries

b. Prior surgical implants

c. Pregnancy

d. All of these

d. All of these

If monitoring is to be achieved by electrical and/or mechanical devices, it is important that compatibility with the MR system be demonstrated by:

a. Clearance by the FDA (Food and Drug Administration)

b. Prior testing

c. Manufacturer declaration

d. All of these

d. All of these

When used for MRI, cables from RF coils and ECG leads should be:

a. Placed straight through the imager

b. Laid along the patient’s right arm, along the bore

c. Formed into loops within the imager

d. Neatly coiled and ready for use

a. Placed straight through the imager

A quench can be used to:

a. Improve image quality in MRI

b. Rapidly remove superconductivity and the magnetic field

c. Maintain magnetic field homogeneity

d. Satisfy the thirst of the technologist

e. Lubricate the magnet coils

b. Rapidly remove superconductivity and the magnetic field

The term used to describe RF absorption is:

a. Sensitive acquisition range (SAR)

b. Specific absorption rate (SAR)

c. Susceptibility attack region (SAR)

d. None of the above

b. Specific absorption rate (SAR)