Liang Develops New Generations of MRI Technology

Nobel Laureate Paul Lauterbur (left) served as a mentor to Zhi-Pei Liang. Photo circa 2004.

With Nobel Laureate Paul Lauterbur, the inventor of magnetic resonance imaging, as a mentor, Zhi-Pei Liang has spent more than two decades tackling MRI problems in domains ranging from physics to signal processing, with a recent breakthrough in molecular imaging. 

Zhi-Pei Liang, a co-chair of the Beckman Institute’s Integrative Imaging research theme and Franklin W. Woeltge Professor of Electrical and Computer Engineering, is a world-class expert in magnetic resonance imaging (MRI). After receiving his Ph.D. in biomedical engineering from Case Western Reserve University in 1989, he was recruited to the University of Illinois by the inventor of MRI, the late Nobel Laureate Paul Lauterbur, who was Liang’s mentor, close friend, and colleague for almost 20 years. 

Liang became interested in MRI when he was a graduate student at Case Western Reserve University, after attending a lecture given by Lauterbur. He was amazed by the capabilities and potential of MRI and decided to pursue his Ph.D. thesis research in this area. 

“Paul had the strongest influence on me, my research, and my approach to pursuing scientific dreams,” said Liang. 

Liang describes his research in this way: “Nuclear spins are one of the most interesting quantum-mechanical systems. Using the signals generated from these systems, MRI has revolutionized biology and medicine over the last three decades. However, current MRI technology has not yet fully exploited the potential of the nuclear magnetic resonance phenomenon to unravel the mysteries of biology and life. Our goal has been to develop new generations of MRI technology to provide unprecedented capabilities for structural, physiological, and functional imaging.” 

Liang’s group has made key contributions to the theory, algorithms, and biomedical applications of model-based MRI. His group is one of the very few in the world that can tackle MRI problems in domains ranging from physics (quantum mechanics and electromagnetics) to signal processing (image reconstruction and machine learning). 

“As Abraham Maslow put it, ‘If the only tool you have is a hammer, you tend to treat everything as it were a nail.’ Our students are well trained in spin physics, engineering, and signal processing, and we have been able to tackle MRI problems from end to end,” Liang said. 

Liang’s research approach has been very fruitful. For example, in tackling the problems of real-time cardiac imaging, Liang and his students used MR physics and signal processing theory to develop a new imaging technique based on the theory of partially separable functions. Their technique can produce high-quality cardiac images from a very small number of measurements, making four-dimensional cardiac imaging possible. This work has resulted in two best paper awards and one NIH R01 grant. Recently, Liang’s group has made another major research breakthrough: molecular imaging using intrinsic NMR signals. Their technology is expected to have a profound impact on the field. 

“It is exciting,” Liang said. “Molecular imaging has been a dream of imaging scientists for decades. Governments and industries have invested billions in this area. However, most existing techniques have to inject molecular probes and molecular reporters into the subject to get molecular information, so their research and clinical applications have been rather limited. Our technique can be a major step forward to change all of that.” 

The University is applying for a patent for Liang’s new technology. 

Illinois has one of the most comprehensive imaging programs, covering imaging modalities from MRI, optical imaging, ultrasound imaging, to nuclear imaging. More importantly, we have people [at Beckman] working on imaging physics, mathematics, computation, machine learning, and biomedical applications under one roof. Their synergistic interactions will sooner or later lead to breakthroughs unobtainable by disciplinary research. - Zhi-Pei Liang

Research from Liang’s group has been recognized by numerous prestigious awards, including the Sylvia Sorkin Greenfield Award, I.I. Rabi Award, IEEE-ISBI 2010 Best Paper Award, IEEE-EMBC 2010 Best Paper Award, IEEE-EMBC 2011 Best Paper Award, the Otto Schmitt Award from the International Federation for Medical and Biological Engineering in 2012, and a Technical Achievement Award from the IEEE Engineering in Medicine and Biology Society in 2014. Liang is a Fellow of the Institute of Electrical and Electronics Engineers (IEEE), the International Society for Magnetic Resonance in Medicine (ISMRM), and American Institute for Medical and Biological Engineering (AIMBE). He was elected to the International Academy of Medical and Biological Engineering in 2012. 

Liang said his accomplishments are due in large part to the outstanding academic environment at Illinois and particularly the Beckman Institute. 

“My research is very interdisciplinary, which fits well with the Beckman academic culture,” said Liang. “I also have wonderful colleagues and top-notch students here. It is an honor and privilege to be a member of this great Institute. Illinois is a fantastic place for doing NMR and MRI work. Pioneering work such as the discovery of spin echoes and the discovery of Overhauser effect was done here, which is very inspiring!” 

The Integrative Imaging research theme was created at the Beckman Institute just over five years ago. 

“The creation of this theme has further enhanced the outstanding research infrastructure and environment in imaging,” Liang said. 

Looking forward, Liang thinks the best time for biomedical imaging is still ahead. 

“Biomedical imaging has been around for more than 100 years since the discovery of the x-ray by Rontgen in 1895. We have witnessed unbelievable progress in biomedical imaging science and technology, which have had tremendous scientific, medical, and societal impacts,” Liang said. “Imaging technology has been traditionally focused on capturing biological anatomical information, but if a disease has already progressed to the level that you can see structural changes, that’s perhaps too late. Next-generation imaging technologies will provide new imaging capabilities to enable physiological and biochemical imaging in high resolution so that we can effectively characterize the physiological states of a biological system and thus detect or predict a disease at very early stages. 

“Achieving this goal could fundamentally affect the way we perform health care as we don’t have to treat a biological system as having only two states: normal or diseased.” 

Beckman researchers are poised to bring next-generation imaging technologies into being. 

“Illinois has one of the most comprehensive imaging programs, covering imaging modalities from MRI, optical imaging, ultrasound imaging, to nuclear imaging,” said Liang. “More importantly, we have people here working on imaging physics, mathematics, computation, machine learning, and biomedical applications under one roof. Their synergistic interactions will sooner or later lead to breakthroughs unobtainable by disciplinary research.” 

Looking Forward 

“Scientific curiosities and wars (yes, wars) have been the drivers for scientific research and technology developments for the entire human history,” said Liang. “Now, our society is confronting major challenges of human health and health care. For the coming decades, I believe, addressing health and healthcare problems will be a key driving force for science and technological development.” 

MRI technology development will continue to be a major focus, but MR will work in concert with other technologies and other fields. Imaging technology breakthroughs are no longer component based, according to Liang, but require an integrated approach to technology innovations. 

“For many decades, imaging technology development has been following a similar model: first, a physical phenomenon was discovered, then imaging technology was developed, and then biomedical applications followed. Such a technology innovation model does not apply to today’s imaging research because, as far as imaging physics is concerned, no fundamental discoveries can be expected —everything from gamma rays to radio waves is known. However, imaging research is not a mature field; revolutionary imaging technologies can still be and will be developed to solve health and healthcare problems.” 

According to Liang, next-generation MRI technology will come from the effective, innovative application and integration of quantum mechanics, electromagnetics, computing, signal processing, and biology.