Researchers using advanced signal processing to enhance image quality

Having an X-ray taken is simple enough: A technician stands behind a protective shield and presses a button, targeting X-rays through the body and striking a detector panel that converts the X-ray energy into electronic signals, which are converted into digital images.

Thanks to Catalyst Grant funding from GE Healthcare, a global company that provides transformational medical technologies and services, UWM faculty member Jun Zhang and his students are researching ways to reduce the cost and complexity of digital X-ray machines, helping medical centers around the world have better access to this important technology.

Imaging Hub

Milwaukee is a mecca for medical imaging. Within a few mile radius, you can trace X-ray’s glass tube advances through to the current digital development. After World War II, the GE X-Ray Corporation moved from the Chicago area to West Milwaukee, according to some reports, in order to tap into the glass-blowing expertise in Milwaukee’s beer-brewing industry.

Now called GE Healthcare, the high-tech facility is only a 15-minute drive to UWM’s College of Engineering & Applied Science where Zhang and his students are using expertise in advanced signal processing to improve the detector cells in the digital imaging systems.

The smaller the detector cell, the more that can be packed into a panel, and the higher the image resolution. Lives are saved every day through decisions made by reading X-rays, but those smaller cells cost more to manufacture – and some parts of the world just can’t afford the technology.

“We want to see if we can use larger detector cells and then use a mathematical technique to make the picture look better,” Zhang says.

Computational Approach

Zhang is providing a computational approach to solving the problem. “Signal processing can include quite a bit of information. If we model the application mathematically, we can enhance the images and implement solutions in hardware or software,” he says.

For instance, they are using a signal processing technique to see if they can improve the image obtained by a panel with 100 micron detector cells so that its image quality is a good approximation to a panel with 50 micron detector cells.

“Significant improvement in the images is possible,” Zhang says.

Using the one-year GE Healthcare Catalyst Grant supplanted with federal funds, Zhang’s team is developing a way to reconstruct images and improves clarity through their mathematical formulas. If it is successful, the payoff is big: Cost reductions for a number of X-ray imaging products without compromising quality – better healthcare at a lower price.

Zhang says his students are fascinated by the project for two reasons:

  • Ideological – They’re curious, smart people who want interesting challenges with innovative approaches that have a broad impact on society. “They’re paid to do something they want to do, playing with ideas and software to solve problems,” Zhang explains.
  • Practical – “The job possibilities after graduation are very good when prospective employers see how students have applied mathematics to find real-world solutions,” he says.

The skills his students are learning will be helpful for careers in telecommunications, computer programming or the military as well as in the many technology companies in the Milwaukee area. But beyond Lake Michigan, the impact on global healthcare can be profound as the clarity of digital imaging is improved and the price is reduced.