MRI safety

MRI Safety This slide show will educate all healthcare providers about the safe delivery of care in the magnetic resonance MR environment.. EMPLOYEE SAFETYALL EMPLOYEES MUST BE SCREENED

MRI Safety

This slide show will educate all healthcare providers about the safe delivery of care in the magnetic resonance (MR) environment.

This slide presentation has been adapted for Nursing

from an original presentation compiled by:

Deborah Schwengel, M.D.

Christopher Pressley, M.D.

Kaadze Wright, M.D.

Robert W Evers, BSRT, MR, CV

THE MAGNETIC FIELD

IS AT FULL POWER

ALWAYS ….IT IS ALWAYS “ON”.

EMPLOYEE SAFETY

ALL EMPLOYEES MUST BE SCREENED

TO WORK IN A MAGNETIC FIELD

ENVIRONMENT JUST LIKE THE

PATIENTS

NO EXCEPTIONS.

MRI PROCEDURE SCREENING FORM

To ensure patient safety, completion of the

MRI screening form is required prior to every

MRI scan Units can assist & expedite the

MRI's triage process by completing this form in advance and faxing to 2-8582

This form is located online at:

http://www.rad.jhmi.edu/requisitions.htm

MRI Screening Sheet

All Patients will need

this form filled out

before an MRI can be done

Ideally, the form should be

filled out by:

What to do in an Emergency

• If there is a Patient Emergency in MRI…

– GET THE PATIENT OUT OF THE ROOM – NO CODE OR CODE LIKE PROCEDURES WILL BE RUN IN THE MRI ROOM.

• It is “possible” for patients to get 1st, 2nd, or even 3rd degree burns in an MRI if items

such as ECG cables are looped and are

touching the patients skin (even if these

devices are MRI compatible).

– All “cables” should not touch the patients skin directly, and should NOT be in a LOOPED

configuration.

What can you take into a magnetic

field?

• ONLY ITEMS THAT ARE MRI

COMPATIBLE Such as…

– Brass

– Aluminum

– Plastic

– IF YOU ARE NOT SURE IF AN OBJECT IS

MRI SAFE…DON’T TAKE IT INTO THE ROOM ASK A TECHNOLOGIST!!!!!!!!

Work closely with the Technologist who works in that type of environment each day Question Everything.

Site Access Restriction:

Screening

• All patients presenting for a non

emergent scan must be screened by two MR personnel, including one with level 2 qualifications.

• A detailed history on possible implants

or metallic objects must be obtained in writing and signed by appropriate

medical licensed personnel

• Do not rely on verbal history alone.

Characteristics of the

Magnetic Field

• the force of the field is measured in tesla (T); a typical scanner is approximately 1.5- 3.0 tesla

• the force of the field is greatest at the periphery

of the magnet This FORCE INCREASES as you move closer to the magnet.

• NOT ALL MAGNETS ARE THE SAME FIELD

STRENGTH, THUS THEIR “ATTRACTIVE FORCES” WILL BE DIFFERENT

Biologic Effects of the Static Magnetic

Field on Persons in its Proximity

questions to consider

• does the field have long term deleterious effects such

as increasing the risk of neoplasm?

• does the field have effects on the patient which alter our monitoring?

• does the field have effects on implanted medical

devices which are non-ferromagnetic and “MR safe”?

To date there is no clear and

convincing evidence that

exposure to high magnetic forces in the MR environment increases the risk of cancer.

Effects of the Static Magnetic Field on Implanted Medical

Devices

Although certain devices such as

implanted pumps may be MR compatible, there are still important

considerations in this patient

population.

• Questions should be directed to the

chief MRI technologist.

There several reports in the literature describing the occurrence of sudden death in the MR for patients with implanted (but MR compatible) pacers

To date the mechanism of these fatalities

is unclear but is thought to be secondary

to the induction of fatal arrythmias

Therefore pacemakers are currently a contraindication to MR scanning

Forces in the MR Environment

• Magnetic field

– missile effect: TRANSLATION

– rotational effect: ROTATION/TORQUE

• the force is greatest when the difference in field

strength across the object is greatest; where delta T

or difference in field strength from point A to point B is maximized

Rotational Force

• this force relates to the North - South orientation

of the scanner’s magnetic field

• ferrous objects will attempt to align their long

axes with this orientation

• this force will rotate objects until they are aligned and is greatest at the very center of the field

(unlike the translational force which is greatest where the difference in magnetic field across the object is greatest)

Another danger in MRI

-QUENCH!

• MR scanners are supercooled with inert gases such as

helium

• If these cryogens BOIL OFF either intentionally or

unintentionally, a quench has occurred THIS IS

EXTREMELY BAD

• An INTENTIONAL quench is done in an emergency to run the magnetic field to ZERO in order to remove a

projectile/patient from the scanner in extreme emergencies

• If a quench occurs, remove all staff from the room

immediately

Another danger in MRI

-QUENCH!

• THE WORRY WITH A QUENCH IS THE POTENTIAL FOR ASPHIXIATION AND FROST-BITE TO THE HEALTH CARE WORKER AND PATIENT.

Pregnant Patients or

Personnel:

• Pregnant patients regardless of

trimester are only scanned if the results

of the study will change the care of the patient.

• Pregnant MR personnel are

encouraged not to stay in the room

during the scanning process.

Introduction to the zone

system for maintaining safety

in the MRI suite

Site Access Restriction

– All personnel with access to MR must have either level 1 or level 2 qualifications.

– Level 1 personnel are minimally trained in

MR safety and can ensure their own safety and the safety of a patient in the MR

environment.

– All JHH anesthesiologists must have level 1 qualifications.

• Level 2 personnel are extensively

knowledgeable about the MR

environment, the potential hazards of the agents and equipment used, and

Safety Zones

• Zone 1 : This is a public access area with

no restrictions.

• Zone 2 : This is a semi restricted area

where patients and hospital staff can

Remember this mnemonic:

MRI =

The End