introduction this course is designed to inform individuals of the necessity of magnetic resonance...

IntroductionIntroduction

• This course is designed to inform individuals of the necessity of Magnetic Resonance Imaging (MRI) safety.

• Any individuals that are in contact with an MRI environment and have knowledge of MRI techniques would greatly benefit from this lesson.

• Click the right arrow to advance slides, and the left arrow to go back to the previous slide

MRI SafetyMRI Safety

© Tiffany Heider, 2005

It could mean the difference between life and death!

What is MRI? What is MRI?

Magnetic Resonance Imaging (MRI) is becoming very popular within the world of medical diagnosis and research. MRI is a technique that uses a magnetic field and pulses of radio wave energy to provide pictures of organs and structures inside the body. For an MRI procedure, the area of the body being studied is positioned inside a strong magnetic field. The MRI can detect changes in the normal structure and characteristics of organs or other tissues. Due to the strong magnetic field, there are many safety issues to consider with this type of testing. Inadequate knowledge can result in serious injury and possible death.

Who gets MRIs? Who gets MRIs?

Everyday individuals, such as you, could one day have an MRI. As well as your family pet, or a sick zoo animal. Their safety depends on your knowledge.

Magnetic FieldsMagnetic Fields

There are 2 Types of magnetic fields

Main magnetic field-responsible for the alignment of nuclei.

-always on -the middle of the magnet (inside

the bore)

Fringe or static field- stray magnet field outside the bore of the magnet

-always on -No respect for confines of walls

or doors, floor or ceilings -MRI room is shielded to

confine the fringe field to inside the room

Types of magnets, cont.Types of magnets, cont.

Why do I need to be safe?Why do I need to be safe?

Patients lives are in your hands and they trust that you do not abuse that. Patient screening, in-depth knowledge, and proper precautions are expected of you.

MRI safety precautionsMRI safety precautions Patient and personnel screening is the

most effective way to avoid potential safety hazards.

Patients or personnel with metallic implants should be examined.

Screening forms should be filled out by anyone entering the MRI exam room.

Screening forms should be filled out completely and correctly. Patients unable to fill out a screening form must have a family member fill it out for them.

Biological EffectsBiological Effects

No radiation is used in MRI, MRI is based on the transmission of radio waves.

No biological or adverse effects No biological or adverse effects to fetus or

pregnant women. -because of cell division during the first

trimester it is recommended by the FDA that women do not have an MRI in the first trimester unless medically necessary.

ProjectilesProjectiles Ferromagnetic metal objects can

become airborne. - small objects (paper clips,

hairpins) can reach the velocity 40 mph

Surgical tools such as hemostats,scissors, and clamps. Even ones made of surgical stainless steel can be highly magnetic.

O2 tanks -All objects tested with hand-held

bar magnet first.

Projectiles, cont.Projectiles, cont. Janitors and cleaning crew must

also be aware of MRI precautions. Buffers and cleaning tools can be attracted by a magnet.

Vendors working on MRI equipment must also be trained and have the proper MRI tools that are nonmagnetic.

It is the departments responsibility to assure no unauthorized persons are to entire a scan room.

Implants/ProsthesesImplants/Prostheses

Metallic implants in patients or employees must be identified before entering room.

Heating and Torque can occur-can cause serious effects

Metal Implants can also cause artifacts on the films

ContraindicationsContraindications

A factor that renders the administration of a drug or the carrying out of a medical procedure inadvisable.

Intra Cranial Vascular ClipsIntra Cranial Vascular Clips

Absolute contraindications, under no condition may that person enter the MRI room.

Motion of the clip may damage the vessel resulting in hemorrhage or even death.

Intra Vascular and Extra Intra Vascular and Extra Cranial Coils, Filters, Stents Cranial Coils, Filters, Stents

Intra Vascular coils, filters, and stints - 8 weeks post surgical, check with the

technologist prior to the exam.Extra Cranial vascular clips -4-6 weeks after implantation-also check

with technologist prior to exam

Vascular Access Ports and Vascular Access Ports and Heart valve implantsHeart valve implants

Vascular access ports are MRI compatible

Heart valves are usually compatible, however the type and model number is required to be checked prior to the test.

-Usually safe after 8 weeks post implantation and scar tissue has formed around the implant.

Ontological or Ear and Ocular Ontological or Ear and Ocular or Eye Implantsor Eye Implants

Cochlear implants- all contrainindicated

Ocular implants-some are ferromagnetic-all patients need to be screened thoroughly.

Intra ocular foreign body- metal in the eye.

-all patients who work or grind metal need to have an x ray before having an MRI.

-Metal in the eye could could heat up or move causing blindness.

Contrainindications for MRIContrainindications for MRI

Cardiac Pacemakers Cochlear Implants Tissue Expanders Ocular Prosthesis Neurostimulators Bone growth stimulators Defibrillators Drug Infusion pumps Intracranial Vascular

Clips-i.e. aneurysm clips

ClaustrophobiaClaustrophobia

Claustrophobia- the fear of being in enclosed spaces.

Many people suffer from this and some patients may need to be sedated before having an MRI.

Proper sedation monitoring must be used.

SUMMARYSUMMARY

MRI suites are a valuable but potentially dangerous medical tool.

MRI magnets are always on. The smallest metallic object can be attracted into

a MRI magnet. Patients must be screened prior to examination. Any individual entering the MRI scan room must

be properly trained on the hazards. Patient and employee safety must always come

first.

ASSESMENTASSESMENT

Next you will be asked a series of questions testing your knowledge on the given material.

You will be given a question/scenario and a choice of answers. Choose the best answer and click to the next slide to see an explanation of answers.

This is for your benefit so please so looking ahead at the answers.

Question 1Question 1

Who are MRIs designed for?

1. Very sick individuals2. Individuals with trauma or physical injury3. Individuals with experimental consent4. Animals5. All of the Above

Question 1 AnswersQuestion 1 Answers

The correct answer is #5 All of the above. MRIs do not treat just deathly ill individuals, or individuals with recent trauma. An MRI can diagnosis all kinds of diseases or injuries in all people as well as animals.


Sally is an MRI technician. They are not in the middle of a scan and she wants to get the scan room organized. Since there are no scans going on it is okay for Sally to take her cell phone into the room with her.

1. True2. False

Question 2 AnswerQuestion 2 Answer

The correct answer is #2 False. MRI magnetic fields are always active regardless if there is a scan going on. As long as the machine has power the magnetic field is present in the room.


Mark is an MRI supervisor. His department has gotten backed up with patients and they are running behind. He knows the next patient has an accurate health history and tells his technician to skip the screening form. Is Mark’s decision the correct one?

1. Yes, he is the supervisor.2. No, the form should be filled out.


The correct answer is #2 No. Even though the patient has a complete health record and Mark is the supervisor, safety should never be disregarded. The patient could have implants or other metallic objects that could be attracted to the magnet. These objects could result in patient injury or death. The screening form must be complete.


Which of the following are NOT a MRI safety hazard.

1. Medical scissors2. Patient oxygen tank3. Radiation4. Hair pins5. Metal implants


The correct answer is #3 Radiation. A MRI suite does not use radiation as in CT suites. A MRI machine uses magnetic fields and radio waves rather than radiation waves. However any material made of metal that is not non-magnetic may be attracted into the magnet.


A patient states that they have a metallic implant. However, they also inform you that they have had an MRI before, and it will not attract to the magnet. If the patient says it will not attract, then you should:

1. Continue with the exam.2. Advise that the exam cannot be completed.3. Have the patient sign a waiver.


The correct answer is #2 Advise that the exam cannot be done. If you were to scan that patient and something were to happen, then you would be responsible. It is better to notify your superiors and the patient rather than be liable for an injury or death that could result in a lawsuit and personal emotional stress.


A vendor comes in to work on your MRI injector. You are headed out to lunch, but want the work to get done. What do you do to accommodate both of you?

1. Give him the keys to the room and go to lunch2. Tell him to come back3. Ask him if he is MRI safe before allowing him

into the room while you are gone4. Ask him to pull the unit out of the room before

you go to lunch and work on it outside the room.


The correct answer is #4. Ask the vendor if he can work on the unit outside of the MRI scan room. This allows you to observe the individual while in the room, lock the room once he is done, and be sure that no magnetic tools enter the room. If he is unable to pull the unit out ask him to come back or have a collegue supervisor the MRI room.


True or FalseA patient informs you that he/she gets

nervous in tight spaces. Since this is the case, you cannot perform an MRI on this individual.


The correct answer is false. Many individuals have Claustrophobia. The MRI bore is a very tight fit, but a patient can be sedated. However, there must be a nurse there to perform the sedation and a qualified individual to monitor MRI compatible monitoring equipment.

CONGRATULATIONSCONGRATULATIONS

YOU HAVE COMPLETED THE MRI SAFETY ASSESMENT. I HOPE YOU

HAVE RECEIVED A LOT OF VALUABLE INFORMATION AND USE IT IN YOUR DAY TO DAY CAREER.

ReferenceReference

Westbrook, C. Kaut, C.(1998). MRI in Practice. MRI Safety, chp 10. Blackwell Science.ltd.

The American Heritage Dictionary of the English Language, Forth edition.(2000).Houghton Mifflin Company

introduction this course is designed to inform individuals of the necessity of magnetic resonance...

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