By Thom Wellington

MRs have become a key non-invasive diagnostic tool used by doctors in hospitals and clinics around the world to investigate organs and tissue within the patient’s body.

A magnetic resonance (MR) imaging scan uses two powerful magnets to create a magnetic field to temporarily realign hydrogen atoms in the body. The hydrogen atoms contain a proton which serves as a magnet during the MR scan. As a patient enters the instrument, the MR’s first magnet causes the water molecules in the body to align in one direction. The second magnet is turned on and off, causing the hydrogen atoms to alter their alignment. The equipment’s computer creates a detailed cross-sectional image allowing for medical interpretation.



Since these commonly used instruments contain such powerful magnets, they can also be a safety risk requiring only specially trained technicians to operate and control the area around the magnets. Architects design the rooms to be safe from surrounding areas, and specialized metal detectors are used to make sure no one enters with a ferromagnetic metal which would be attracted to the magnetic force of the MR scanner. The magnets are never completely turned off, even at night making these super-cooled helium instruments a possible safety risk 24/7. Consequently, normal cleaning and disinfecting of the instrument between patient scans is a specialized task.

According to Darrel Hicks, author of Infection Prevention for Dummies and principal of Darrel Hicks, LLC, a national expert on health care cleaning and disinfecting, “the cleaning responsibilities for the MR equipment vary from one facility to another. Many have the radiology staff responsible for cleaning the equipment, including the tube where patients are examined. Environmental services (EVS), the housekeeping staff in hospitals, normally do not clean the MR equipment due to the special precautions and safety hazards.”

Since most accidents in an MR area are caused by human error, special precautions and training are necessary and constantly updated. The magnet in an MR is about 30,000 times as powerful as the Earth’s magnetic field. Some of the accidents that have occurred become horrible news stories such as a young boy who was undergoing an MR examination when the magnetic field yanked a metal oxygen tank across the room, crushing the boy’s skull. A fireman fighting a blaze in a hospital was sucked into the scanner's bore by his metal air tank and a policeman’s gun was pulled by the magnet’s tremendous force from his holster and went off when it hit the equipment. Sensational stories demonstrate the projectile effect of ferromagnetic objects to the magnet and the importance of continual safety awareness.

It is estimated that there are over 10,000 MR devices in the U.S. and more being installed weekly due to demand for the accurate medical analysis they provide. Deborah Campbell, infection prevention improvement advisor to the Kentucky Hospital Association, stressed, “the technicians at each MR location are well-trained and carefully screen for potentially dangerous items. For that reason, they are commonly tasked with disinfecting the equipment itself.

Manufacturer instructions are thorough and also provide safety information as well as how to properly clean and disinfect the units.” Campbell noted, “ultimately, the hospital decides on the type of disinfectant needed to perform the cleaning work. Additionally, many facilities have special safety training for all staff that may enter the area and this typically includes a select number of EVS staff that performs floor care and cleaning of other common non-patient-care items in the room such as desk surfaces.”

The imaging equipment is also changing to allow for more advanced medical analysis of musculoskeletal conditions. Equipment manufacturers, along with doctors and researchers, are modifying MR equipment to simulate stress-loading for spine imaging. The purpose is to create situations mimicking actual pressures on the body to better understand simulated usage and provide doctors with possible solutions, all with the goal of better patient outcomes. Additionally, MRs are also being redesigned to allow for greater flexibility in patient positioning. The advantage of expanding the range of positioning is that it greatly increases the diagnostic usage of the instrument. Typical MR bores are extremely limiting and can cause claustrophobia in some patients and limit the size of the patient that can comfortably be examined, as well as limit the diagnosis.

Unfortunately, as Americans grow older and experience the wear and tear on their bodies, the need for musculoskeletal information has significantly increased. The value of MR scans continues to increase as new advances are made in the design of the equipment. The steady constant is the danger the magnetic force creates in the exam room. Staff must be constantly vigilant, and continual training is necessary beyond simple onboarding. MR equipment must be cleaned and disinfected to provide an infection solution barrier for patients, no matter who is tasked with the duty.

About the author: Thom Wellington is the CEO and a stockholder in Infection Control University.