Diseases affecting moving organs such as the heart and lungs require dynamic imaging rather than static scans, yet limitations in current MRI technology often hinder early detection and diagnosis. Traditional MRI sensors are costly, rigid, and unable to conform closely to the body, reducing image quality and flexibility. To address this, researchers at the University of Southern California developed a low-cost, silver-ink MRI coil that can be 3D printed in under 10 minutes for patient-specific use. The coil costs about $30 in materials — significantly less than traditional models — and delivers up to four times higher image resolution, improving access to more reliable dynamic imaging.
USC researchers, Yasser Khan and Krishna Nayak teamed up to develop a new silver-ink based MRI coil that costs about $30 in consumable materials, compared with at least thousands of dollars for industry-standard coils, and delivers up to four times higher image resolution. The coils can also be 3D printed in real time in under 10 minutes, enabling patient-specific customization.
The study has removed key barriers in dynamic imaging and represents a major breakthrough in MRI technology, with broad applications in clinical settings such as pediatrics and cardiology.
The work was made possible by bringing together two researchers from USC Viterbi School of Engineering and USC Mark and Mary Stevens School of Computing with expertise in wearable sensors for precision health and MRI imaging: Khan, an assistant professor in the Ming Hsieh Department of Electrical and Computer Engineering and with joint appointments in the Alfred E. Mann Department of Biomedical Engineering, who leads Khan Lab; and Nayak, a professor of electrical and computer engineering, also with a joint appointment in biomedical engineering, who leads the Dynamic Imaging Science Center (DISC). The research was also spearheaded by Félix Muñoz, a student they co-advised, as well as Ye Tian, a research assistant professor in the Ming Hsieh Department of Electrical and Computer Engineering. The team also included Prof. Min-gu Kim, an assistant professor of medical engineering at Yonsei University in Korea.
John Wood, a close collaborator from the Keck School of Medicine of USC and the Children’s Hospital Los Angeles, emphasized that this is a game-changer, noting that MRI screening is a platform technology essential for detecting undiagnosed conditions in patients, including children and infants. He added that coil sensors play a critical role in diagnostic accuracy and clinical decision-making.
Expensive and Low-resolution MRI Scanners
Like cameras that detect light waves to form images, MRI scanners process and create images or videos using radiofrequency (RF) signals.
The visual data is made possible with MRI “coils,” which are specialized antennas placed close to the bohiiidy part being imaged to detect weak radiofrequency signals emitted by tissues, acting as the receiver for producing high-resolution images.
In the MRI world, the equivalent of camera resolution is called signal-to-noise ratio (SNR). To capture motion in MRI scans, specialized low-field MRI (0.55T) is used to enable dynamic, real-time imaging of motion-intensive processes by leveraging reduced susceptibility artifacts and faster data acquisition.
However, capturing video is particularly difficult at low magnetic field strengths (0.55T) because the signal is inherently weaker, which leads to lower SNR, and consequently lower resolution. Low SNR reduces image quality, making it more difficult for physicians to make accurate clinical assessments.
Today’s standard commercialized coils face many challenges, with low comformity being the biggest limitation. Current coils, typically made of copper, are rigid and follow a one-size-fits-all design. They cannot maintain the close contact required to recover enough signal for high-quality, video-rate imaging. The closer the sensors are to the signal source, the clearer the “picture,” and the closer a coil is to the anatomy, the better the resolution because proximity increases signal strength.
Existing MRI coil arrays are also expensive, priced between $10,000 and $50,000 each.
These high costs are driven by complex manufacturing processes, proprietary markups and rigid, specialized construction that can take significant time to produce. This cost and manufacturing complexity reinforce rigid designs as the commercial standard, making personalization difficult and continuing to limit imaging accuracy.
The limitations of current MRI technologies heavily affect babies and children, as Wood explained that existing coils are designed for adults and then scaled down for children, a process that often fails to accommodate the rapid anatomical changes in growing infants. This sizing mismatch makes MRI screening less accurate in pediatric patients. He also noted that “an infant’s heart can be as small as a walnut,” requiring a coil that is equally small and well-fitted to produce accurate results—something that current, non-customizable coil designs cannot adequately provide.
Silver-based MRI coils as solution: Flexible as human skin and engineered for higher SNR
In the study, Khan’s team aims to tackle the low SNR problem by designing coils that better fit the skin, allowing sensors to be closer to the body.
The lab first experimented with innovative materials that could maintain strong signal performance while being flexible enough to conform to the body like human skin—a longstanding challenge in MRIs for dynamic imaging.
A major limitation with flexible or printed conductors is that they typically have lower conductivity than solid copper, which introduces resistive losses and reduces signal-to-noise ratio (SNR). On the other hand, current industry-standard copper coils lack the flexibility needed to maintain close contact with the body. As high conductivity is key for strong SNR, most flexible materials have historically failed to deliver imaging performance comparable to copper.
Khan’s lab identified silver as an optimal material as it offers conductivity comparable to copper while enabling flexibility when printed onto soft, rubber-like substrates such as thermoplastic polyurethane (TPU). The researchers tested various silver inks and selected one formulation, FS0142, that achieved approximately 95% of the signal efficiency of a standard solid copper coil—the first time researchers are able to successfully address the conductivity challenge while maintaining flexibility for dynamic imaging at lower field.
The silver ink is combined with a specialized binder that makes it stretchable, allowing the printed coil to stretch between 5% and 10%, closely matching the natural stretchability of human skin. This enables the coils to wrap tightly around complex anatomical structures, such as the wrist, while maintaining consistent contact.
These new coils, which are as soft and stretchable as human skin, overcome the longstanding tradeoff between rigidity and conductivity. By ensuring a conformal interface where the coil remains in constant contact with the body, the design can effectively replace traditional copper coils while significantly improving imaging performance.
The $30 Breakthrough: 3D-Printed Coils That Are Customizable in Under 10 Minutes
The new coils are also drastically cheaper in both material cost and manufacturing, dropping the price of a standard coil from as much as $50,000 to about $120 per coil.
Muñoz explained that this is partly because the quantity of material needed per coil in his team’s study is extremely small, bringing the consumable cost to roughly $30 per element, despite silver being an expensive and precious metal.
The other key aspect contributing to the low cost is the lab’s automated workflow, which enables coils to be completely 3D printed. Unlike traditional coil manufacturing, which requires complex machinery, proprietary processes and intricate assembly steps that are costly, labor-intensive, the new coils introduced in the study can be produced in as little as eight minutes per element.
These coils are designed using standard Gerber files—the same format used to manufacture circuit boards—allowing for a fully digital workflow. By using automated tools such as the Voltera NOVA printer, a direct-ink-write system, the need for manual routing or complex housing assembly is eliminated, enabling rapid digital fabrication.
This innovation not only reduces cost but also expands the potential for MRI to become more accessible, instead of a limited, high-cost resource. The simple, low-cost, real-time production of these coils allows for on-demand manufacturing tailored to specific patients or body parts, further addressing the longstanding challenge in customization. This makes it possible to create coils of varying sizes, including those small enough for infants.
Because the coils are inexpensive and can be analyzed using low-cost, portable tools, the technology could expand access to high-quality MRI in rural or resource-limited settings worldwide.
At USC, New Coils Meet the World’s Only Low-Field High-Performance MRI System
This work was made possible through a unique collaboration at the University of Southern California, where the newly developed coils could be directly tested on a rare high-performance low-field MRI system—creating an environment that enables proprietary research, innovation and cross-disciplinary collaboration.
A key advantage is the close partnership between Yasser Khan’s lab, which developed the coils, and the Dynamic Imaging Science Center. The center houses a highly specialized MRI scanner: a 0.55 T low-field prototype, a modified 1.5 T Siemens MAGNETOM Aera system, that is now the only one of its kind still operating in the world.
The scanner at DISC offers several technical advantages that make it an ideal match for the new flexible coil technology. Its advanced gradient system enables extremely fast scans, which are essential for capturing high-quality, video-rate dynamic imaging. At the same time, like most low-field MRI systems, the scanner at DISC suffers from lower signal. The flexible coils developed in this study address that limitation by improving signal capture and image quality.
What’s Next: Clinical Use and Patient Testing
The study’s MRI coils have generated strong interest among physicians. Khan said the team’s goal is to move the coils from the lab into clinical settings, with patient testing as a key next step.
Nayak identified pediatric lung imaging as a likely first clinical application to be tested, with John Wood expressing strong interest in eventually adopting the technology for patient care.
“It starts with a signal,” Wood emphasized, noting that regardless of the medical condition, the diagnostic process begins with signal and image quality. He said the study introduces significantly improved signal strength, which could enhance MRI as a platform technology across many diseases and help physicians make more accurate clinical judgments.
Wood emphasized that the technology could be especially impactful for the smallest and most fragile patients, including premature infants. An infant’s heart is extremely small and beats rapidly, making it traditionally difficult to image. Improving signal by bringing the “lens”—the coil—closer to the body allows for clearer visualization of these tiny, fast-moving structures. Screening is a critical first step in identifying conditions in infants, who are more vulnerable to heart and lung diseases or structural abnormalities that require accurate imaging.
Wood also envisions new diagnostic pathways for common infant conditions, including monitoring lung development in bronchopulmonary dysplasia, evaluating swallowing function to prevent aspiration, and studying gastrointestinal malformations.
Muñoz also highlighted applications in wrist injuries, which require clear dynamic imaging of moving joints to identify conditions. In testing, the team’s wrist coil arrays achieved four times higher contrast and five times greater sharpness than commercial coils, allowing clinicians to resolve fine structures such as carpal ligaments that were previously difficult to see.
While the coils were developed to address challenges in dynamic imaging, Wood sees broader applications in standard, still-image MRI scans across a range of clinical settings.
For more information: Nature Communications
Image: The study’s new MRI coils. (Photo Credit: USC Khan Lab)
