By Liberty Franks

The use of printing for MR coils makes them flexible and tailored to the size of each patient.

Long exam times, patient discomfort and claustrophobia are major issues in the MR suite that result in delays, failed exams and ultimately affect the bottom line. Novel printed, flexible coils could be the solution that hospitals and other MR operators are searching for to achieve good exam outcomes, increase patient satisfaction, and reduce costs.

Patients come to the MR suite in all sizes, shapes and physical conditions, yet currently they must all fit in the same narrow bore and wear the same coils. While making the bore wider is the task of scanner manufacturers, InkSpace Imaging, a Berkeley-based startup, uses printed electronics to make tailored coils that are extremely comfortable, to fit patients perfectly. InkSpace believes that MR coils themselves are a major cause of the challenges in MR use and outcomes.

“Traditional coils are bulky, heavy and expensive,” said Michael Lustig and Ana Claudia Arias, co-founders of InkSpace Imaging and professors at UC Berkeley . “They are designed as one-size-fits-all, so they often do not fit the patient properly.” This issue is responsible for heightened patient discomfort and lower image quality. Research from the Lustig and Arias’ groups at UC Berkeley has shown that a distance of only one inch (2.5 cm) between the coil and the patient can result in a decrease of more than 20% of image signal to noise ratio.

The founders of InkSpace came together with combined decades of industry and academic experience in both MR and printed electronics and the conviction that MR scanning of patients as we know it could be radically improved. At the heart of their patented technology is screen-printing, a relatively simple, thousand-year-old printing process, commonly used to print patterned T-shirts.

By using conductive inks, InkSpace can print the coils’ electric circuit on thin, flexible substrates, resulting in lightweight, blanket-like arrays that are each inexpensive to make. The printed blanket coils are then attached to a cable containing the conventional circuitry needed to interface with the scanner. With their printing technology, InkSpace’s solution consists of a collection of flexible, blanket-like coils, tailored to fit each patient size perfectly, for the same price as a single one of today’s coils.

The flexibility allows the coils to fit snug to the patient’s body, thus improving image quality, and the thin, light feel is particularly important for patient comfort.

As important as flexibility is the fact that each coil is adapted to the patient’s size: this ensures that all the channels of the coil contribute to the scan. This is especially true for the small bodies of pediatric patients.

“If you take a 32-channel adult array to scan a 5-year-old patient” Lustig said, “in practice, only a small number of channels, 8 or 10, are actually on the patient and capture the signal. All the others only contribute to noise.” This is detrimental for image quality and prevents the reliable use of acceleration techniques, such as parallel imaging.

Developing coils for pediatric patients was the original motivation for the invention of printed coils. It started when Lustig attended a presentation by fellow UC Berkeley professor Arias, a printed electronics expert.

“After my talk”, Arias recalled, “Michael came and asked if I could print coils. ‘What are coils?’, I replied, and that is how it began.” With the addition of then-Ph.D. student Joseph Corea and Dr. Balthazar Lechêne as a postdoc, along with other group members, their team worked closely with Stanford pediatric radiologist Dr. Shreyas Vasanwala to address the absence of adequate scanning coils for pediatric patients.

It took 6 years of development to reach the point they are at today: testing their lightweight coils on more than 100 pediatric patients at Stanford’s Lucile Packard Children’s Hospital. InkSpace’s printed pediatric coils are even wrapped in a friendly, dinosaur-patterned fabric that kids respond to enthusiastically.

“InkSpace Imaging’s printed coils enhance patient safety and comfort, and make exams less stressful,” notes Dr. Vasanawala.

One of Dr. Vasanawala’s 5-year-old patients was known to be very nervous and fidgety during exams. Typical of small children, he was scheduled to have general anesthesia prior to the scan. However when he came for the exam, he started naming the dinosaurs on the InkSpace “blanket” coil and was able to go through the whole exam without anesthesia. In fact, he reacted so well to the experience that his exam lasted 30 min instead of the two hours scheduled.

Children are often sedated for MR exams due to the length of time they need to stay absolutely still to capture the diagnostic image. Due to the unnatural space and movement restrictions upon patients during MR exams, even a significant portion of adult patients require some kind of sedation in order to go through with the exam.

Given the health implications of sedation and negative emotional stress, InkSpace makes the case that anything that reduces the length of exams and increases comfort directly results in more successful outcomes for patients, their families, and diagnosticians alike. And it helps improve the bottom line of MR units too.

According to research published in the Journal of the American College of Radiology last year, exam delays or failures caused by undesired patient motion and claustrophobia affect, on average, 10 to 15 percent of all MR exams, and the MR operators must bear most of the associated costs. With more than 40 million exams performed in 2016, it can be estimated that lost revenue due to patient motion amounts to more than $4 billion per year in the United States alone.

Currently, InkSpace Imaging has a 12-channel prototype and they are developing a 24-channel prototype for body imaging of 3-5 year-old patients. They are working toward getting their first FDA-approved device to market within the next two years.

There have been regular attempts by the industry to improve upon the conventional coils and address their limitations. Certain coils from the latest generation are much lighter and flexible, such as the GE AIR technology coil, or ScanMed Blanket coils. But printing seems to offer additional benefits, such as patient tailored coils and reduced production costs. Overall, the use of novel production processes could transform the way the industry thinks about coils, and InkSpace aims to do just that, one dinosaur-print blanket at a time.

About the author: Liberty Franks is a Bay Area communication and marketing consultant. She works with dynamic technical startups to tell the stories of their innovations.