There are several signs that can be used to assess a person's medical condition. These signs, known as biomarkers, are objective indicators observed from outside the patient. Biomarkers provide more accurate assessments of health than symptoms, which rely solely on patient perception.
GW Biomedical Engineering Assistant Professor Junghun Cho researches mapping of the oxygen extraction fraction (OEF), a biomarker that measures how efficiently brain tissue consumes oxygen. Prof. Cho recently received additional funding from the National Institutes of Health to support his work on developing more efficient and accessible methods for mapping OEF, particularly in patients with multiple sclerosis (MS), whose condition may make existing methods less effective.
“Current OEF mapping techniques are not routinely available and are often impractical for most clinical applications,” Cho explained. “Some MRI-based methods may only be available in specialized MRI settings, and others may require patients to inhale gas or undergo vascular challenges that can cause discomfort,” he said.
The prevailing method of OEF mapping, the QQ method, is a quantitative MRI mapping technique. The QQ method combines two other methods: Quantitative Susceptibility Mapping (QSM) and quantitative blood oxygen level-dependent modeling. It relies on physiological assumptions that may not hold for patients with MS, leading to inaccurate OEF estimates.
Cho is collaborating with GW doctoral students and colleagues from Washington University in St. Louis and SUNY Buffalo to develop an enhanced version of the QQ method. The new approach, known as QSim (QSM for phase modeling + diffusion-aware Monte-Carlo simulation for magnitude modeling), aims to eliminate unrealistic assumptions and integrate both phase and magnitude information, providing a more detailed picture of a patient’s OEF.
In May 2025, the team submitted an abstract of their work to the International Society for Magnetic Resonance in Medicine, the largest magnetic resonance imaging society, and received a magna cum laude distinction.
Cho is optimistic that the ongoing funding will enable his team to continue their innovations, allowing clinicians to better capture and track brain oxygen consumption in patients with multiple sclerosis.