Hillsborough’s Quadridox Is Looking At X-ray Technology In A Whole New Light

The Quadridox founding team. Dr. Joel Greenberg (who is both the CEO and CTO) is in the middle.

Led by medical physicist Joel Greenberg, Hillsborough-based Quadridox is taking X-ray technology a step forward by putting a novel kind of X-ray projection—called X-ray-diffraction—into applications that can range from airport scanners to food inspection to tissue biopsies.

For those of you unfamiliar with the ins and outs of X-ray technology, here is your quickie lesson in X-ray 101 from Greenberg, a former associate research professor in medical physics at Duke.

Most X-ray images people are familiar with—for example, the kind you would see on a broken bone in a show like Grey’s Anatomy—are made with “transmission X-ray imaging,” which shines light through an object (like a broken leg) and looks at the shadow an object creates.  These images are great for creating high resolution images with fine details, but not for distinguishing materials from one another, Greenberg said.

By using a computational sensing framework, Greenberg’s team has developed a way to capture the light that scatters off of an object instead of goes through it, adding X-ray diffraction as an additional layer of depth to traditional transmission imaging.

“The physics of that is not new,” Greenberg said. “X-ray diffraction is a tool that’s been used over the last 100 years. It was part of the Watson and Crick double helix DNA structure analysis; there’s one on the Mars Rover. It’s typically the domain of material scientists who want to understand the structure of things. What we’re doing is we’re taking conventional X-ray imaging, that makes these nice, pretty pictures, and we’re adding to it. We’re going from that black and white to color images, where the color here is this extra bit of information about what things are actually made of by measuring the scatter signal.”

In security applications, this technology can make the difference between TSA missing an explosive device or finding it with ease. In medicine, this technology can mean doctors are able to distinguish between a malignant tumor or a benign one just by looking at an X-ray. After researching medical physics for almost a decade at Duke University, Greenberg realized it was time to spin this technology off into its own startup to test the possible life-saving applications in the private sector.

Quadridox’s technology would enhance TSA’s ability to find restricted items, which is why the startup has received a $5.83M grant from the Department of Homeland Security.

So in 2018, Greenberg took the leap of turning his research into a product and founded Quadridox, a startup focused on turning his findings into solutions. The first few years of Quadridox’s startup life were spent in research and development, paid for largely by federal agencies who saw the security benefits offered by X-ray diffraction technology.

Over the past year, the Quadridox team has been working on turning this research into a real product, with notable success. The team wowed a group from TSA who travelled down I-40 to Quadridox’s headquarters in Hillsborough to see its prototype suitcase-searching technology at work. It was also a finalist for one of NC IDEA’s $50K SEED grants.

While putting its security technology to work is a longterm goal for Quadridox, in the near future, observers should expect a late 2022 or early 2023 launch of a medical device for examining “ex vivo” tissue, or tissue that has been extracted outside of the body.

“We’re not doing live person in-vivo diagnostics, we’re looking at excised tissue like you would have after a biopsy or a surgical resection, like breast lumpectomy,” Greenberg said. “We’re focusing on how this technology can be used to aid clinicians in doing the same type of imaging with material analysis as we’ve done in the security domain. We’ve been straddling both of these things, and we care very much about both the aviation security space and the medical imaging space.”

Evolving into Quadridox 2.0

In both the security and medical field, Greenberg said, the company is seeking partnerships and investors to push Quadridox into version “2.0.” Previously, much of the company’s funding has included government grants, including a $5.83 million grant in 2019 from the Department of Homeland Security and a $250K grant earlier this year from the NC Biotech Center. Quadridox is seeking investors in the lab sciences and medical field who are invested in their mission to improve applications of X-ray diffraction technology.

Working both as Quadridox’s CEO and CTO, Grenberg has been able to focus on “cool science” while learning the ins and outs of managing a business at Durham’s First Flight Venture Center, where Quadridox was located before making the move down I-40 to Hillsborough during the pandemic.

Greenberg hasn’t stopped R&D even as his team nears the finish line on some of its prototype technology—remaining a thought leader in X-ray technology is important to him and critical to his business, he said. With a team of five full-time and a few part-time employees working on the company’s vision, Quadridox is well equipped to tackle the market and the research all at once.

“I think one thing that academics are good at doing is learning new things, and so I have seen this as my own personal lesson in teaching an old dog new tricks,” Greenberg said. “I’ve been doing the science thing for a long time, and it’s just been really cool to jump into something totally new.  Especially how important all the non-technical aspects of the whole problem are, and how to attack making decisions with as much information as you can, but not all the information that a scientist might like.”