Cardiovascular Image｜Research Team

Intrigued by coronary plaque images and entering the field of cardiovascular imaging

I was also interested in the treatment methods unique to cardiovascular medicine such as catheters. However, I think I was more intrigued by the theoretical aspects such as the pumping function of the heart. Thus, I decided to specialize in cardiovascular medicine because of my deep interest in arteriosclerosis.

While studying abroad at the University of California, I came across the latest image analysis technology and became fascinated by it. After experiencing animal experiments using nuclear molecular imaging, I started working on the study of coronary plaques in arteriosclerosis. When I returned to Japan, coronary CT was getting more common in clinical practice. Therefore, my research topic was focused on arteriosclerosis and image analysis using coronary CT for plaque.

Research focused on plaque analysis by coronary CT

Of the overall cardiac diagnostic imaging field, our group focuses on three fields; CT, MRI and cardiovascular nuclear medicine. I joined Juntendo University in 2013 and at present, I have more opportunities to collaborate with companies and the Department of Radiology, which reallyinvigorate my research work.

In addition to analysis of plaque properties, it has recently become possible in coronary CT to evaluate hemodynamics including calculation of fractional flow reserve(FFR) by using computed fluid dynamics, in which area we are mainly conducting researches. We pride ourselves to be at the top level in this field in Japan.

My personal research focuses on CT and nuclear medicine. One of the salient features of my group is the fact that we are proactively writing papers on proton nuclear magnetic resonance spectroscopy (1H-MR Spectroscopy：MRS), which only a handful of facilities in Japan are able to conduct. Applying MRS to the heart enables detailed component analysis of the myocardium. In particular, the ability to quantify triglyceride present in the myocardium is extremely innovative and we have published the results of our research in which this method is applied to athletic heart diagnosis.

Research on triglyceride deposit cardiomyovasculopathy, which is a new disease concept originating in Japan, is also underway. Doctors at Osaka University are taking the lead in filing an application for designating this disease as an intractable disease and our group is also a member of the research team. We are striving to establish diagnostic methods and therapeutic effects by combining MRS and nuclear medicine.

Achieving accurate and speedy risk assessment with minimally invasive image inspection

Through joint research with companies, we were able to develop and put into practical use a new coronary plaque analysis software using clustering analysis technology.

Research is also underway on a method for calculating FFR from coronary CT. Although there are currently only a limited number of facilities in Japan that uses HeartFlow's FFRCT, which is covered under medical insurance for reimbursement, we have been using it from a relatively early stage to conduct research at multiple facilities under our hospital’s initiative. We are also researching how to analyze FFR from CT using other algorithms and have most likely published the maximum number of papers in Japan. While practical application is not yet in sight, we will continue to be a front runner in conducting this research.

We regard our research to be useful in obtaining accurate diagnostic and therapeutic guidelines. In the field of coronary artery disease, diagnostic imaging has the advantage of being less invasive than catheterization, which is likely to be the first and easy option. If it becomes possible not only to detect coronary artery stenosis but also to perform plaque evaluation and measure FFR by means of imaging, a more accurate diagnosis, treatment and risk assessment may be achieved. This will prevent the patients from unnecessary catheterization or revascularization treatment and will also make it possible to proactively carry out intervention for high-risk patients. If we are able to save the lives of patients more efficiently and more precisely, medical expenses may be curtailed and many other benefits will be gained.

Using the continuously evolving image technology to improve the accuracy of risk assessment

We also conduct some research using artificial intelligence (deep learning) for assessing prognosis and evaluating risks by CT data; we have some research to improve the diagnostic accuracy of the coronary artery calcification, which is obtained by non-enhanced CT. Furthermore, since the current coronary CT cannot evaluate molecular imaging such as inflammation of coronary plaque, we have some animal experiments for developing new contrast media.
Ultimately, we hope to integrate these technologies and comprehensively evaluate plaques, hemodynamics, myocardial blood flow, etc. from one cardiac CT imaging to achieve high-precise unstable plaque identification and cardiovascular event risk assessment.

Actively engaging in joint research with other groups and departments

In addition to the advantages of a private university, where we can handle a large number of cases, one of the salient features in our university is that we have experts in various fields and a very favorable environment for collaboration. For example, the coronary artery disease / SHD group is an expert group of invasive imaging technology, but we are the experts of non-invasive imaging such as CT. Through this collaboration, we can view problems from different perspectives.

Collaboration with the radiology department also runs very smoothly. Originally, diagnostic imaging falls under the category of the radiology department. However, doctors in the cardiovascular medicine do use these images in clinical practice. In other words, no matter how proficient both departments are respectively, there is a risk of not being able to reach the correct conclusion without collaboration. In this respect, the collaboration in our university runs smoothly and we can complete each other. We continue to conduct joint clinical research actively with the radiology department for utilizing artificial intelligence (deep learning), or evaluating myocardial ischemia and myocardial blood flow by myocardial perfusion CT, and etc.

Involving young researchers and entrusting them with the dream of discovering new diagnostic imaging

Cardiovascular images provide a visible representation from which we can perceive the state of the biology and pathology. I suggest a new era has begun. Various information will be obtained from images, including biomolecular information. I think this imaging field will become even more interesting in the future.

I think it would be really wonderful if we discover new diagnostic methods and disseminate them throughout the world. It may seem like a dream, but I would like to continue to be a pioneer in research and provide stimulation to a new generation of researchers in the cardiovascular imaging field.

Shinichiro Fujimoto