Your Guide to Operating an MRI Safely
An MRI generates high-powered magnetic fields to capture diagnostic images. As you can imagine, there are some very important safety protocols that must be put into place to operate an MRI without risk. It's one of the reasons why an MRI must be installed in its own specialized room. The following is a guide that will help you understand the safety concerns regarding the operation of an MRI and what must be done to help ensure the safety of your patients and staff.
When Can Operating an MRI be Dangerous?
MRIs are often considered safer than other diagnostic imaging systems due to the lack of radiation produced. Instead of using X-rays, MRI systems produce powerful magnetic fields and radio waves. Although an MRI exam does not cause any kind of pain or tissue damage, there are a few potential risks, including the following:
- Magnetic attraction - The magnets used in MRI systems are extremely powerful. Many closed MRI systems are built using a 1.5T magnet, which produces a magnetic field almost 21,000 times greater than the earth's natural field. This kind of a magnetic field will cause metal objects in the vicinity of the MRI to be drawn through the air to the MRI system. When these objects become airborne, they can pose a serious threat to anyone or anything in its path. Even something as small as a paper clip could reach a terminal velocity of 40mph when pulled in by a 1.5T magnet.
- Electronic disturbances - When a magnetic field is generated, it can cause disturbances to electronic devices. This means it could cause cell phones, analog watches, cameras, and more to shut down or malfunction. It will also erase credit cards and debit cards with magnetic strips. More alarmingly, the magnetic field an MRI produces can cause hearing aids and pacemakers to malfunction.
- Magnet quench - A quench occurs when the magnetic field generated by the MRI is completely shut down, whether on purpose or by accident. When a quench happens, the magnet coils experience a sudden loss of absolute zero temperature. This causes the magnet coils to become resistive instead of superconducting, thereby eliminating the magnetic field and resulting in the escape of helium (which will turn from a liquid into a gas) from the cryogen bath at a rapid pace. Gas helium that isn't ventilated out of the room will displace the oxygen in the room, which can lead to asphyxia.
- Thermal burns - Thermal burns are rare, but they can occur when the radio-frequency field generated by an MRI induces currents in wires that are on or near the patient. Prolonged imaging can also result in the core body temperature of the patient to rise.
- Hearing issues - Although not as problematic as the previously listed risks, MRI systems are quite loud, which means patients could potentially experience some hearing issues following their scan.
Some of these risks are obviously serious, but they can be all but eliminated completely as long as the proper safety precautions are followed.
Safety Precautions MRI Operators Need to Follow
Considering all of the potential risks that can occur during the operation of an MRI, it's absolutely essential that your staff follow every possible precaution to ensure the safety of both your patients and your employees. The following are some of the safety precautions you should take:
Follow All Rules of Conduct and Best Practices
Implement these rules for all staff who not only operate your MRI system but for all who enter the MRI room:
- Empty pockets - Before entering the MRI room, both patients and staff should remove everything from their pockets, including things like smartphones, pagers, keys, pens, change, and more. If anyone forgets to empty their pockets, any electronic devices can end up malfunctioning while metal items could become dangerous projectiles.
- Wear MRI-compatible clothing - Some types of clothing may contain metallic microfiber, which can cause thermal burns. It's important that patients are provided with scrub tops and bottoms before being scanned.
- Keep MRI room closed - The door to the MRI room should be kept closed at all times unless someone is entering or exiting the room. This will help reduce RF noise during imaging and ensure that the magnetic field won't disturb anything outside of the room.
- Check MRI system before scan - The bore should be thoroughly inspected for any unplugged surface or body flex coils. Scans should never be performed if these are present.
- Only use approved equipment - No research equipment, supplies, or coils should be used unless it has been approved by an MRI safety committee or official.
- MRI room should be kept clean - Following scans, all equipment needs to be returned to its proper place to keep the room clean and organized. Coils and phantoms should never be placed on the floor.
- Never leave patients unattended - Patients being scanned by the MRI should never be left unattended. If the staff member in charge of overseeing the MRI scan needs to leave the room, they should get another staff member who is qualified to cover for them.
- Understand emergency procedures - Every staff member responsible for overseeing MRI use needs to be familiar with your code procedures in the event of a medical emergency.
Minimize the number of staff present in the MRI room at any given time to reduce the risk of something going wrong. The person in charge of screening staff may lose track, resulting in someone bringing in a ferromagnetic item. Or there may be confusion over who is responsible for what, leading to mistakes in your safety protocol.
Only level II staff should have access to your MRI room. These employees should have the training and knowledge concerning the operation of an MRI system and the safety risks involved. Level II staff include MRI technologists, MRI nurses, and radiologists. They are responsible for making the MRI room a safe environment. Level I staff, such as physician's assistants, ICU nurses, floor nurses, and public safety personnel should not be granted access to the MRI room unless they are closely monitored by a member of your level II staff.
No Extra Objects
Besides common ferromagnetic items that staff and patients may carry on their person (smartphones, keys, change, etc.), there are other ferromagnetic items that should be kept outside of the MRI room. In fact, you'll want to limit what's in the room even if it's not ferromagnetic in order to keep the space clean and clear. Do not bring wheelchairs, stretchers, monitors, oxygen tanks, or IV pumps in from outside the MRI room. There are special versions of this equipment that should be kept within the MRI room at all times.
Scan All Staff and Patients For All and Any Metal Objects
Everyone who enters the MRI room, whether it's a level I staff member, a patient, or family of a patient, needs to be carefully scanned by a level II staff member. Not only should all potentially ferromagnetic items be removed from their person, but they need to be screened for metal implants. This might include pacemakers, metal shrapnel, metal in the eyes, heart valve replacements, and more.
If someone does have a metal implant, an orbital X-ray will need to be performed and the images will need to be cleared by a radiologist before they can enter the MRI room. Depending on the conclusion drawn by the radiologist, they may not be allowed in the MRI room.
Tattoos and Makeup
Besides metal implants, patients with tattoos or makeup on may experience some discomfort due to fact that some makeup and tattoo ink contain iron. Patients should remove all makeup and should inform the MRI specialist overseeing their scan of any tattoos that they have. The patient should be directed to mention any discomfort they might have in tattooed areas during the scan.
The MRI system can be very loud. Patients should be offered ear plugs to help reduce discomfort caused by the loud noise as well as help reduce the risk of hearing issues caused as a result.
What Are MRI Safety Zones?
MRI magnets are always on. Because of this, safety is an issue at all times. To help ensure safety around the MRI, the MRI environment should be divided into four zones. Each zone has its own specific safety requirements and restrictions to follow.
Where are MRI Safety Zones?
The following are the four safety zones that your MRI environment should be divided into:
Zone 1: Outside
Zone 1 consists of the area outside of the MRI facility. It's completely safe for all staff and the general public to move around in without supervision. Although there will be some magnetic fringe fields generated in this area due to the strength of the MRI, they are so minimal that they will have no effect on anyone in this area.
Zone 2: Waiting / Reception Areas
Zone 2 is the waiting and reception area that lead to the control room. It's a public area that is still safe, but that should be properly supervised in order to prevent unscreened individuals from entering into Zone 3. It's in Zone 2 that patient and staff screenings are typically conducted by level II staff members.
Zone 3: Near the MRI Room
The magnetic field generated by the MRI will be relatively strong in Zone 3. Because of this, nobody should enter this zone unless they have been fully screened and outfitted with MRI-appropriate clothing. Zone 3 is also where the computer room and control room are located. Patients are generally led from Zone 3 to Zone 4, which is the MRI room.
Zone 4: Inside the MRI Room
Zone 4 is where the MRI system is located and where the magnetic field is the most powerful. There should always be a level II staff member supervising the room if anyone else is present. All ferromagnetic objects must be kept out of this room to eliminate potentially serious injury and damage risks.
In The Event of an MRI Emergency
As long as safety precautions are taken and safety protocol is carefully followed, MRI emergencies are extremely rare. However, that doesn't mean an MRI emergency can't occur. If a patient experiences problems, they will need to be checked for responsiveness and immediately removed from Zone 4 and taken to a designated recovery area. Code Blue will need to be called in and a staff member will need to direct traffic in the hallway outside the MRI room if needed. The door to the MRI room should be closed before the Code Blue team arrives.
If the patient's life is in danger and they cannot be removed from the MRI room due to the malfunction of the MRI equipment, then a quench should be performed. If a fire breaks out in the MRI room, the patient should be escorted out immediately. Hopefully, your sprinkler system will be automatically activated. If it's not, a quench will need to be performed in this situation as well.
When a quench is performed, the MRI room will need to be immediately cleared. The MRI room should be shut and the alarm should be pulled. 9-11 will need to be called and a Code Red will need to be reported. The hallway outside the MRI room will have to be evacuated as well.
A quench should only be performed in life-threatening emergencies. Once a quench is performed, the MRI will be inoperable for weeks. There's also a risk that quenching the magnet will be irreversible. On top of that, quenching is a dangerous procedure since it can result in frostbite, asphyxiation, or hearing damage to anyone who remains in the MRI room for too long following the quench.
Protect Your Patients, Personnel, and the MRI
MRIs are considered completely safe to use as long as your staff follows the proper safety protocols. Safety should always be a priority and as long as your staff is well trained and doesn't cut corners, there's no reason to think that your staff or patients will be at risk. Taking every possible safety precaution will not only protect everyone in your MRI room, it will also help protect your MRI equipment.