Common MRI Coil Failures

We’re 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 content with all of our clients. Coil lifecycle can be affected by several factors: Random electronic failures, general wear, premature wear, and preventable damage/trauma. Innovatus has amassed a large amount of failure analysis data after repairing almost 45,000 coils.

Simply stated, the majority of MRI coils sent to Innovatus have a root cause associated with physical, mechanical, or preventable damage. 55% 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, are paying upward of $50,000 or more, out-of-pocket, for an exchange coil from the OEM when the failure is classified a preventable.

Common MRI Coil Failures: The System Cable

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.

Your Solutions

• OEM Cable replacements: If available, they are extremely costly, with some approaching $15,000.
• Common 3rd-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.

Common MRI Coil Failures: Flex Coils

Another common failure applies to flexible coils. Flex coils are designed to be draped across or 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.

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 compromised handling and transportation practices.

Your Solutions

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 95% of all flex coils, which saves you time, money, and provides confidence with a 6-month warranty.

Preventing and Minimizing Common 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’s 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.

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. 

One Final Note:

A good strategy to compliment 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. Latest breakthroughs include repairs to Philips fiber optic dStream™ coils and GE Air™ coils.