MRI Safety Chapters 3 & 4; Read Chapters 1 & 2

What are the arrows pointing to?

magnetic fringe field lines around the MRI scanner

What is the MRI Zone II?

MRI Patient Screening and Preparation

What is MRI Zone III?

Screened MRI Patients and Personal Only

What is MRI Zone IV?

Screened MRI Patients Under Direct Supervision of Trained MRI Personnel Only

What does the image warn?

Restricted Access Strong Magnetic Field

What does the image show?

Ferromagnetic object being pulled into the magnet

What does the image show?

Some Ferromagnetic Objects

What does the image show?

Results of Missile Effect

What does the sign stand for?

MR Safe

What does the sign stand for?

MR Unsafe

What does the sign stand for?

MR Conditional

What are the guiding principles of MR safety?

MR personnel must be educated, remain vigilant in a dynamic environment, and apply that knowledge to screening and safety throughout time in the MR Suite

What defines Level 1 MR Personnel?

Individuals with minimal MR safety education who may work in Zone III and may enter Zone IV only with escort by Level II personnel

What defines Level 2 MR Personnel?

Individuals extensively trained in MR safety, including risks such as thermal loading, burns, and neuromuscular excitation, with authorized access to Zone IV

Who identifies Level II MR Personnel?

The MR Medical Director

What is the MRI scanner fundamentally?

A very large and powerful magnet

What is the typical field strength of clinical MRI scanners?

1.5 to 3.0 Tesla

What field strength is beginning to appear in MRI?

7 Tesla magnets

How many gauss is 3 Tesla?

30,000 gauss

How strong is Earth’s magnetic field?

Approximately 0.5 gauss

Is the MRI magnet ever turned off?

No, the MRI magnet is always on

Why is MRI unique compared to CT?

The magnetic field is always on and extends beyond the room

What is Zone I in MRI?

A publicly accessible area with no MRI restrictions

What is Zone II in MRI?

The interface between public Zone I and restricted Zone III, where patients are typically screened

What is Zone III in MRI?

A restricted area outside the scanner room where unscreened individuals may face serious risk; access requires training

Why is Zone III dangerous?

Unscreened individuals or equipment may interact dangerously with the MR environment

What must employees entering Zone III have?

Proper MRI safety training

What is a common issue with Zone III compliance?

Many sites cannot meet full engineering requirements

What should sites do if they cannot fully meet Zone III engineering requirements?

Make best effort to evaluate, comply, train personnel, and secure the scanner room

What is Zone IV in MRI?

The MRI scanner room

What must be done with the Zone IV door?

It must always be closed or monitored

What is required for Level 1 personnel entering Zone IV?

They must complete a screening form every time they enter Zone IV

Who are examples of Level II MR personnel?

MR technologists and MR radiologists

What is the role of the MR Medical Director regarding personnel?

They identify individuals who qualify as Level II MR personnel

What is the MRI scanner?

A very large and powerful magnet

What are typical clinical MRI field strengths?

1.5 to 3.0 Tesla

What higher field strength is becoming more common?

7 Tesla

How many gauss is 3 Tesla?

30,000 gauss

How strong is Earth’s magnetic field?

Approximately 0.5 gauss

Is the MRI magnet ever turned off?

No, the MRI magnet is always on

Why is MRI unique?

The magnetic field is always on and extends beyond the room

What is Zone I?

A general public area with no MRI restrictions

What is Zone II?

The interface between public Zone I and restricted Zone III where patients are screened

What is Zone III?

A restricted area outside the scanner room where unscreened individuals may face serious risk

Why is Zone III dangerous?

Unscreened individuals or equipment may interact dangerously with the MR environment

What is required for employees entering Zone III?

MRI safety training

What is a common Zone III compliance issue?

Many sites cannot meet full engineering requirements

What should sites do if they cannot meet Zone III engineering requirements?

Make best effort to evaluate, comply, train personnel, and secure the scanner room

What is Zone IV?

The MRI scanner room

What must be done with the Zone IV door?

It must always be closed or monitored

Who may enter Zone IV?

Only screened patients and screened personnel under proper supervision

Why must Level 1 personnel be escorted in Zone IV?

Because Level 1 personnel do not have sufficient MR safety training to enter Zone IV independently

What is required of all personnel entering Zone IV?

All personnel must be screened before entering Zone IV

What are the permanent bioeffects of static magnetic fields under 10T?

There are no permanent bioeffects from static fields under 10T

What causes most bioeffects from static magnetic fields?

Induced voltages in tissues due to motion through the magnetic field

What sensations may occur when moving through a static magnetic field?

Flashes of light, vertigo, and metallic taste

What is the projectile effect?

Ferromagnetic objects can be pulled violently into the magnet

What are possible results of the missile effect?

Injury to patients or staff and damage to the MRI scanner

What is the definition of an MR Safe item?

An item that poses no known hazards in all MR environments

What is the definition of an MR Unsafe item?

An item known to pose hazards in all MR environments

What is the definition of an MR Conditional item?

An item that poses no known hazards under specified conditions

What should you do if you are unsure whether an item is safe?

Do not guess; consult an MRI technologist for evaluation

What must be completed before an MRI exam can be scheduled?

The MRI Patient Screening Questionnaire

What items are screened for on the MRI questionnaire?

Ferromagnetic items, implants, conductive materials, metallic tattoos, and NSF risk

What must all staff entering the MRI room complete?

An MRI screening form

What is quenching the magnet?

The deactivation of the magnetic field, causing rapid cryogen boil‑off

When should a quench be performed?

Only when someone is pinned by a ferromagnetic object or during an uncontrollable fire requiring ferromagnetic firefighting equipment

Where are emergency quench buttons located?

In each scanner room and control room

Are pregnant healthcare workers allowed in the MR environment?

Yes, they may work in and around the MR environment throughout pregnancy

What activities may pregnant workers perform in MRI?

Positioning, scanning, archiving, injecting contrast, and emergency entry

Where should pregnant workers avoid being during actual MR acquisitions?

Zone IV

What is the purpose of knowing MRI Safety Team contacts?

To ensure staff can reach the MR Medical Director or MRI Safety Officer when safety concerns arise

Who is part of the MRI Safety Team?

The MR Medical Director and the MRI Safety Officer (MRSO)

Why must the MRI scanner room door remain closed or monitored?

To prevent unscreened individuals or unsafe items from entering Zone IV

What barrier is recommended if the Zone IV door is left open?

A caution barrier such as straps or plastic chains

How should technologists position themselves when approaching the patient in Zone IV?

From the far side of the scanner to view the door and avoid projectile paths

Who must supervise Level 1 personnel in Zone IV?

Level 2 personnel must directly supervise Level 1 personnel in Zone IV

Who may enter Zone IV?

Only screened patients and screened personnel under proper supervision

What is required of all personnel entering Zone IV?

All personnel must be screened before entering Zone IV

Are there permanent bioeffects from static magnetic fields under 10T?

No permanent bioeffects occur at clinical field strengths under 10T

What causes most static magnetic field bioeffects?

Induced voltages in tissues due to motion through the magnetic field

What sensations may occur when moving through the magnetic field?

Flashes of light, vertigo, and metallic taste

What is the projectile effect?

Ferromagnetic objects can be pulled violently into the magnet

What injuries can result from the missile effect?

Injury to patients or staff and damage to the MRI scanner

What is an MR Safe item?

An item that poses no known hazards in all MR environments

What is an MR Unsafe item?

An item known to pose hazards in all MR environments

What is an MR Conditional item?

An item that poses no known hazards under specified conditions

What should you do if unsure whether an item is safe?

Do not guess; consult an MRI technologist for evaluation

What must be completed before an MRI exam can be scheduled?

The MRI Patient Screening Questionnaire

What items are screened for on the MRI questionnaire?

Ferromagnetic items, implants, conductive materials, metallic tattoos, and NSF risk

What must all staff entering the MRI room complete?

An MRI screening form

What is quenching the magnet?

The deactivation of the magnetic field, causing rapid cryogen boil‑off

When should a quench be performed?

Only when someone is pinned by a ferromagnetic object or during an uncontrollable fire requiring ferromagnetic firefighting equipment

Where are emergency quench buttons located?

In each scanner room and control room

Are pregnant healthcare workers allowed in the MR environment?

Yes, they may work in and around the MR environment throughout pregnancy

What activities may pregnant workers perform in MRI?

Positioning, scanning, archiving, injecting contrast, and emergency entry

Where should pregnant workers avoid being during actual MR acquisitions?

Zone IV

What is the purpose of knowing MRI Safety Team contacts?

To ensure staff can reach the MR Medical Director or MRI Safety Officer when safety concerns arise

Who is part of the MRI Safety Team?

The MR Medical Director and the MRI Safety Officer (MRSO)

What is the MRI Safety Officer (MRSO) responsible for?

Overseeing MRI safety practices and serving as a point of contact for safety concerns