UB gets $1.6 million NIH grant to improve medical imaging for leg ulcers

BUFFALO, N.Y. – The National Institutes of Health are helping to fund an evolution in medical imaging, and a University at Buffalo-led research team is leading the way.

Jun Xia, PhD, associate professor in the Department of Biomedical Engineering, received a $1.6 million grant to improve medical imaging for people with chronic leg ulcers. The project is a collaboration with the surgery clinic of UBMD Physician’s Group and other UB researchers.

“Chronic leg ulcers are basically a wound on the leg that doesn’t heal,” says Xia, whose research focuses on developing new optical and ultrasonic imaging techniques for use in cancer, vascular, and neurological research and treatments.

“It takes a long time to heal – several months, or years, or it never heals,” he says. “The reason is there is poor blood perfusion to the tissue, which means the blood cannot reach the portion of the injured tissue. If you cut off the blood supply, the tissue will eventually die, and that is why chronic ulcers may lead to poor health outcomes.”

Chronic leg ulcers affect more than 500,000 Americans each year, according to the Cleveland Clinic. They lead to costly treatments, reduced mobility and quality of life, and increased risk of death.

Restoring proper blood flow to the wounded area after surgery is key to effective medical treatment, planning and monitoring. To do that, extensive, efficient medical imaging is needed to properly visualize what is happening around the ulcer. However, current methods, which include X-rays, MRIs and ultrasound, have limitations in evaluating small vessels, which weakens their effectiveness in monitoring blood perfusion to the ulcer.

The four-year research project is focused on finding a noninvasive, accurate imaging tool to assess post-surgical circulation.

“That’s the main purpose of this grant,” Xia said. “Right now, there’s no effective technique to identify whether the blood perfusion has been restored after the surgery.”

The technique he’s developing uses photoacoustic tomography (PAT) to produce effective imaging. Basically, a near-infrared light irradiates the affected area and heats the blood. The blood cells then expand slightly, a process that generates sound waves. An ultrasound machine, which uses sound waves to create imaging, perceives the heat-generated sound waves and translates them into visual imaging. Blood, as a light absorber, is a great generator for sound, which is why the imaging shows the distribution of blood in the affected area, as well as whether proper perfusion of blood has been restored.

In addition to the grant provided by the NIH – specifically, the National Institute of Biomedical Imaging and Bioengineering (NIBIB) – the research project has gained support from vascular clinics at Buffalo General Medical Center Hospital and the Erie County Medical Center. The team has obtained preliminary data with support from UB’s Clinical and Translational Science Institute.

“Our idea is, after the UBMD vascular surgery team has done the surgery to restore proper blood flow, we’ll do the imaging,” say Xia. “We’ll compare the results with the imaging acquired before the surgery to see if there is any change in the blood perfusion to the ulcer. If there is a positive change, then we know the surgery was successful.”

Currently, surgeons are restrained by the lack of imaging techniques to assess distal perfusion. As a result, they end up waiting a few months to see whether blood flow has been restored. Xia wants to bring that wait time to two weeks or less.

“This will allow surgeons to identify earlier than current imaging techniques whether the surgery was successful,” he said.

Additional UB investigators include Linda Harris, MD, professor of surgery, and Sikandar Khan, MD, clinical assistant professor of surgery, both in the Jacobs School of Medicine and Biomedical Sciences: Wenyao Xu, PhD, associate professor of computer science and engineering in the School of Engineering and Applied Sciences; Praveen Arany, PhD, assistant professor of oral biology in the School of Dental Medicine; and Guan Yu, PhD, assistant professor of biostatistics in the School of Public Health and Health Professions.