The Promise of a Resolution RevolutionProfessor Zang-Hee Cho from South Korea uses high-tech imaging technology to study diseases affecting the country.

Professor Zang-Hee Cho from South Korea uses high-tech imaging technology to study diseases affecting the country.

April 02, 2014 | Professor Zang-Hee Cho, Director of Gachon University Neuroscience Research Institute,South Korea, uses high-end magnetic resonance and positron emission tomography to study diseases affecting South Korea today – and those that will affect the country tomorrow – in ways that have literally seldom been seen before.


Text: Walter Foreman
Photos: Julie Mayfeng


South Korea is facing the challenge of an aging population. By 2026, at least 20 percent of the country’s population will be over the age of 65, making it a super-aged society. In addition, according to a 2011 report by the World Bank, life expectancy at birth in South Korea is 80.9 years, up from 70 years in 1988 when Seoul hosted the Summer Olympics, and much higher than the worldwide average of 69.9 years. Unsurprisingly then, the World Bank also reports that Korea’s public health expenditure per capita has increased nearly threefold from 2002 to 2011. With longer life expectancies, it is unsurprising that cases of stroke, Parkinson’s Disease, and Alzheimer’s Disease have risen. To face these growing challenges, Professor Zang-Hee Cho, PhD, uses ultra-high field 7T magnetic resonance imaging and MR-PET to push the boundaries of neurological imaging to provide paradigm-changing insights that lead to earlier detection and more accurate diagnoses. Looking to the future, Cho expects the next decade to focus on what he calls “modern mental disorders” such as sleeping disorders, depression, obsessive compulsive disorder, obesity, and drug addiction.

Professor Zang-Hee Cho, PhD, Neuroscience Research Institute
Professor Zang-Hee Cho, PhD, Neuroscience Research Institute

Coming from humble beginnings selling cigarettes after the devastation of the 1950-53 Korean War, Professor Zang-Hee Cho, PhD, is now among the world leaders in ultra-high field (UHF) magnetic resonance imaging (MRI) and high-resolution research tomography (HRRT) positron emission tomography (PET) neuroimaging. Often described as a pioneer in the field – like the living UHF legend Professor Kamil Ugurbil, at the Center for MR Research University of Minnesota (CMRR), Minneapolis, USA – Cho remains as committed today to seeking answers to neurological clinical questions as he was 38 years ago when he developed the world’s first “Ring PET” in 1975. It is only fitting then that for the past ten years, Professor Cho has cooperated with Siemens as both strive to advance human health through innovation.


Focusing on the Human Brain
Cho developed a PET and MRI fusion system for in vivo molecular imaging of the human brain using two high-resolution imaging devices: the HRRT-PET tomograph dedicated to brain imaging on the molecular level, and the 7-tesla (T) MRI system, an ultra-high field magnetic resonance imaging system, which are located in two adjacent rooms and coupled by shuttle. HRRT-PET allows observation of the brain's molecular changes using the specific radioligands and probes. On the other front, the 7T MRI system enables submillimeter visualization of brain morphology, providing detailed delineation of cortical and subcortical areas as well as of the brainstem.


Professor Zang-Hee Cho and his team at Gachon University, South Korea
Professor Zang-Hee Cho and his team at Gachon University, South Korea

Korea’s Aging Society
Today, Cho and his team use the systems to focus on the diseases associated with older patients. Since 2000, the country has been characterized as an aging society, with seven percent of its population aged 65 or older.1 By 2018, South Korea is expected to be an aged society, with over 14 percent of its population over 65.2 And by 2026, the country is expected to be super-aged, with more than 20 percent of its people aged over 65.3 What is more, South Korea will have undergone this transition to a super-aged society faster than any other nation on Earth.4 It is no wonder then that Professor Cho and his team use their MAGNETOM® 7T UHF MRI scanner5 to seek answers to the questions surrounding stroke, Parkinson’s Disease, and Alzheimer’s Disease.


Stroke in Korea

Statistically speaking, stroke afflicts someone in South Korea every five minutes and results in a death every 20.6 It accounts for roughly 10 percent of deaths in the country, and in 2005 the total cost of stroke care in Korea was 3.73 trillion Korean Won (US$ 3.3 billion).7 And, if there can be any good news in these numbers, it is that they can be decreased through early diagnosis and treatment. “We can prevent stroke, provided you are able to look at the patient in advance,” notes Cho. “But if the resolution is poor, you can’t see anything. With the MAGNETOM 7T5, you can see very clearly, down to about 0.2 millimeters.”
Professor Cho’s non-invasive in vivo visualization of the microvasculature of the human brain using magnetic resonance angiography (MRA) at 7T plays a significant role in the study of small vascular abnormalities, which can be early predictors of stroke. His work is replicated universally in the UHF imaging sector.  


High resolution images improve identification of brain substructures.
High resolution images improve identification of brain substructures.

7T Imaging in Parkinson’s Disease Patients
In addition to stroke, Cho also brings his insights – and Siemens’ technology – to the study of Parkinson’s Disease (PD). He uses 7T MRI to generate images with unprecedented levels of resolution and contrast that allow direct targeting of structures for placing the electrode of Deep Brain Stimulators (DBS) in PD patients. As Professor Cho describes, the difference between existing low-field MRI techniques and his 7T imaging is the difference between night and day.


In Vivo Ultra-high Resolution Imaging in Alzheimer’s Disease
The unmatched resolution offered by 7T imaging technology also aids Cho in the detection of Alzheimer’s Disease (AD). In 2007, he was the first to show in vivo ultra-high resolution images of the hippocampus. Today, using these ultra-high resolution (300 µm isotropic) images, he can clearly identify and delineate substructures of the hippocampus as well as closely monitor any morphological changes in disease progression.


The world’s first circular ring PET scanner, developed by a team led by Z. H. Cho at UCLA.
The world’s first circular ring PET scanner, developed by a team led by Z. H. Cho at UCLA.

Future Applications of 7-tesla Imaging Technology
When asked about the future applications of his research, Professor Cho talks of what he calls “modern mental disorders,” including sleep disorders, depression, and obsessive-compulsive disorder. With the high-resolution images produced by his hybrid MR-PET scanner and the ability to see “something that you’ve never seen before,” Cho feels that the mechanisms causing these disorders can be better understood, including their origins and their behaviors. These, according to Cho, need to be studied for the next decade or more. Going beyond these disorders, he also sees applications of his high-resolution imaging to the study, and possibly treatment, of obesity or drug addiction.
Although not currently available for clinical use, Professor Cho and the Neuroscience Research Institute have most likely scanned more subjects at 7T than any other place on earth. Almost 4,300 people have undergone the procedure since the Institute first used the technology in 2006. In those early days, the NRI was one of just three places in the world to have 7T imaging technology. Today, there are approximately 60 such places. Siemens provides technology and assistance to some 40 of them.
Whether it be understanding the diseases affecting Korea today, or those that will affect the country tomorrow, one thing is certain: Professor Cho is a true pioneer in medical imaging, and his quest for answers through his high-field superconducting MRI systems has brought about the promise of a revolution in ultra-high resolution neuroimaging.


Walter Foreman is the manager of communications and protocol at Korea University in Seoul and the host of an hour-long talk-show on Seoul’s first and only 24-hour all-English radio station. Originally from Canada, he has lived in South Korea since 1998.