What are the most common failures on MRI coils?

We are often asked, “What are the most common failures on MRI coils? Since so many have asked, independently of each other, we thought that it would be a great idea to share the information with the MedWrench community. 

How and Why Do MRI coils fail?

Coil lifecycles can be affected by several factors: Random electronic failures, general wear, premature wear, and preventable damage/trauma. Based on data captured in the past 2-years, spanning over 5,000 coil repairs, over 34% of all MRI coils present with mechanical damage due to preventable damage or trauma. An additional 18% possess failures RELATED to preventable damage/trauma (totaling about 52%). About 28% are related to general wear and less than 20% are actually failing due to random electronic component failures.

Simply stated, the majority of MRI coils sent to Innovatus have a root cause associated with physical, mechanical, or preventable damage. 52% is a very strong data point in that most service contracts do not include failures related to preventable damage (or only allow for several preventable events).

Facilities paying a premium to include MRI coils on their magnet’s service contract, may pay upwards of $50,000 or more, out-of-pocket, for an exchange coil from the OEM when the failure is classified as preventable.

Isn’t your data limited? How can your data relate to ALL, or most, MRI coils?

This is a great question. Innovatus Imaging, and its legacy companies, have been repairing MRI coils since the mid-1980s. Since about 2000, our team has repaired nearly 50,000 MRI coils spanning over 1000 unique models. In the past year alone, we’ve repaired over 2,400. During each repair, we track and trend the reported problem, the associated findings, and perform root cause/failure analysis. Our partnerships span multiple Original Equipment Manufacturers (OEMs), other Independent Service Organizations (ISOs), healthcare facilities worldwide, asset management organizations, as well as standalone imaging centers. To say that we have a good cross section of global MRI coil failures is an understatement. 

What are some of the components within an MRI coil that fail most frequently?

System Cables

One of the more frequently encountered points of failure is the system cable. Cable failures begin as intermittent issues that progress to hard failures, similar to any tethered device. Users typically begin to experience RF signal dropout, system ID failures, and/or bias control voltage failures. The results begin to present as image artifacts and ultimately QC failures. Although system cables will become intermittent over time, most cable failures are related to one, or several, acute events that accelerate or exacerbate the cable’s natural lifecycle.

What are typical solutions to address cable failures? 

• OEM cable replacements: If available, they are extremely costly, with some approaching $15,000.
• Common third-party/ISO solution: A common strategy to address cable failures in the repair industry is to patch and splice an individual intermittent/broken wire. The reality of that approach is that, if one wire in the cable harness has become intermittent, the rest are likely compromised and will most likely result in a latent failure. 
• Innovatus Solution: Our approach to cable failures is to rebuild the entire cable harness. This approach resets the cable’s lifecycle and offers clients the longevity they expect. Innovatus is able to fabricate replacement system cables, including fiber optic cables.

Flex circuitry

Another common failure applies to what are now called, traditional flexible coils. Flex coils are designed to be draped across (but not wrapped around) a region of interest. Embedded within the flexible areas of the coil is complex circuitry mounted to and connected by flexible copper traces. As you can guess, continued flexing will degrade and damage the flex circuits and is one of the more common points of failure on these types of coils.

Caption: Photo and X-ray image of a traditional smaller flex coil from Siemens Healthineers

Similar to cable failures, flex circuit failures begin as highly intermittent issues that progress into hard failures. Common to flex coil failures are stress fractures and tears in the flexible traces underneath the foam covering. Many times, there are no signs of physical damage to the foam, yet the underlying circuitry has become compromised. That being said, a solid percentage of flex coils present with tears to the foam as well as the underlying circuitry due to improper handling and transportation practices.

What are typical solutions to address failures to traditional flex circuits? 

A common approach to repair flex circuit failures is to cut and fold-back the foam covering, bridge/patch the broken flex circuit with copper material, and then reseal the foam. In extreme cases, when there are many compromised areas, the entire flex area needs to be replaced, and the entire coil needs to be re-foamed. Each repair provider has their own unique approach. Degrees of success and repair longevity are based on the materials and techniques employed. Innovatus is confident in its approach, as coil repairs are warranted for 6-months. Innovatus has the ability to perform re-foaming in-house on about 98% of all flex coils, which saves time, money, and provides like-new performance and appearance.

Has the design of flex coils improved over time?

The newest style of flex coil resembles a blanket. The most notable are the GE Air™ coils but other OEMs are updating their designs. These newer designs have eliminated the traditional copper flex circuits, as well as the foam, the most-frequent points of failure. The entire coil is flexible and can be totally wrapped around the anatomy. All of the circuitry is mounted on a flexible, very lightweight, ribbon-like, conductive material, and is embedded within a protective, vinyl-like, cover. 

Caption: Various layers of a GE Air™ coil

Despite the radical technological and material advances within these new coil designs, Air™ coil users have been beginning to experience failures associated with continued flexing and stretching of the internal circuitry. The challenge is that traditional repair methods are no longer applicable to these innovative designs. 

Innovatus engineers have been able to develop comprehensive repair solutions to address the challenges of this recent technology. Our repair teams are not limited by any of the recent technology, components, or high-tech flex circuitry within the Air™ coils. As with all of our repair solutions, our in-house engineers develop full schematics, bills of materials, proprietary tools, and test procedures relative to each coil’s unique design. It’s a confident “Yes”, that Innovatus can repair your Air™ coil.

Do you have some tips and best practices to help prevent and minimize MRI coil failures?

There are several strategies for preventing and minimizing coil failures. Based on historical trends, the life cycle of most MRI coils is based upon the level of care and handling employed by end users.

• One solid practice that can help to offset preventable damage is proper cable routing practices and following the recommended process for connecting and disconnecting the coil from the magnet. To avoid opportunities for preventable damage, users may just need to pause for a second and look around.
• Another best practice is to be sure that the coil is unplugged prior to lowering the table. Failing to do so may damage the coil, cable, or connector and is traditionally NOT covered under the warranty or service contract.
• Continuing with the last point, hasty actions are often the cause of much of the preventable damage seen, and most OEMs are very clear regarding patient placement practices. For example, when using a flex coil, it is important for technologists to NEVER attempt to adjust the position of the patient by moving the coil, as it may cause both physical and internal electro-mechanical damage. Also, flex coils should never be transported holding the foam section. The foam sections are not designed to support the weight of the coil.
• As many body, spine, and torso coils are large, heavy, and quite cumbersome, it is best to transport them with a cart (an MRI-safe cart, of course).

Establishing a well-communicated set of policies and best practices are the most effective methods of addressing failures within user control. These would span practices related to periodic inspection, proper storage, transportation, patient placement, and cable routing practices as well as proper cleaning and disinfection processes. 

Do you have any final recommendations? 

A good strategy to complement an MRI service contract is, if an MRI coil possesses any signs of physical damage, address that failure through repair versus the service contract. The result would reduce the costly out-of-pocket expense to a few thousand dollars.

Innovatus has repair capabilities on over 1,000 models of MRI coils. We have a solution for you. Including the new ,blanket-style, coils, our latest breakthroughs include repairs to Philips fiber optic dStream™ coils and fabrication of fiber optic system cables. For more information, or to arrange for a repair, please contact customercare@innovatusimaging.com 

Ted Lucidi is an industry veteran with nearly 40 years of experience supporting the Healthcare Technology Management (HTM) community. His career spans more than two decades as an in-house service engineer, followed by a similar tenure working with both OEM and ISO organizations—giving him a well-rounded perspective on the challenges and opportunities within the field. Since 2000, Ted has also served as an instructor in Penn State’s Biomedical Engineering Technology program, where he shares his deep technical knowledge and real-world insights with the next generation of HTM professionals. His passion for education and mentorship reflects his broader commitment to partnering with and uplifting the HTM community.