In the featured article of the March 2017 issue of "The Journal of Nuclear Medicine," researchers demonstrate that a new positron emission tomography (PET) radiotracer, gallium-68 (Ga-68)-pentixafor, can quickly and non-invasively identify life-threatening atherosclerotic plaques. The tracer binds to the CXCR4 receptor on inflammatory cells present in atherosclerotic plaques--making it possible to find and treat atherosclerosis early.
Atherosclerosis represents the main cause of heart attack and stroke. According to the Centers for Disease Control and Prevention, every year about 735,000 Americans have a heart attack and 800,000 have a stroke. Stroke kills more than 130,00 Americans a year, and about 610,000 die from cardiovascular disease.
Note the high uptake of Ga-68-pentixafor on multi-planar reconstructions in the organs expressing CXCR4 such as the spleen (red arrows) and adrenal glands (yellow arrows), which was nearly completely blocked by the pre-injection of AMD 3100, a potent CXCR4 inhibitor. Strong accumulation of Ga-68-pentixafor was also found in the kidneys (asterisks) reflecting the renal clearance of the tracer. In addition, high, focal activities were detected in the abdominal aorta (red arrowheads) and right carotid artery (orange arrowheads) of atherosclerotic rabbits, whereas no significant signal could be detected in the non-injured left carotid artery (white arrowheads) of atherosclerotic and control rabbits, as well as in the abdominal aorta and right carotid artery of control rabbits. Furthermore, focal activities detected with PET in atherosclerotic plaques of the abdominal aorta and the right carotid artery decreased significantly when the same rabbit was re-imaged after blocking CXCR4 receptors.
Credit: Fabien Hyafil,MD, PhD, Department of Nuclear Medicine, Klinikum Rechts der Isar, Technische Universität München, Munich, Germany
Atherosclerosis develops over decades with the progressive accumulation of lipids, inflammatory cells and connective tissue within the inner layer of arterial walls leading to a local thickening of the vascular wall called atherosclerotic plaque.
These plaques can remain asymptomatic for years, but an inflammatory reaction can develop causing the plaques to rupture and stimulate clot formation. If a clot completely blocks an artery, no oxygen can reach the downstream tissue--resulting in the sudden development of heart attack or stroke. The challenge is to identify patients with these dangerous atherosclerotic plaques before a heart attack or stroke occurs.
Currently, there is no clinically available non-invasive imaging technique specifically to detect inflammation. F-18-fluorodeoxyglucose (FDG)-PET is being used but has important limitations. It is taken up by many cells other than inflammatory cells, including cardiac and brain cells.
The strong signal present in the organs next to the arteries limits the precise analysis of the radiotracer uptake in atherosclerotic plaques. In addition, patients need to fast at least six hours before FDG injection to avoid interferences with blood sugar and muscular uptake of the tracer that impair image quality.
"Ga-68-pentixafor binds more specifically to inflammatory cells than FDG and does not require the patient to fast for six hours before imaging," explains Fabien Hyafil, MD, PhD, of Klinikum Rechts der Isar, Munich, Germany, and Bichat University Hospital, Assistance Publique, Hôpitaux de Paris, Paris, France.
In the study, the specific binding of Ga-68-pentixafor to inflammatory cells located in atherosclerotic plaques was first validated in an animal model. Seven atherosclerotic rabbits and five controls were imaged on a PET-MRI system after injection of the tracer. Resulting images clearly showed inflammation in plaques in the abdominal aorta and right carotid artery of the atherosclerotic rabbits. The researchers also confirmed with a small number of human patients that the radiotracer detected atherosclerotic plaques located in their carotid arteries.
Hyafil emphasizes, "This new radiotracer will strongly facilitate the imaging of inflammation in atherosclerotic plaques with PET and hopefully support the early detection and treatment of atherosclerosis, thus preventing heart attack or stroke."
Authors of the article "Imaging the cytokine receptor CXCR4 in atherosclerotic plaques with the radiotracer 68Ga-pentixafor for positron emission tomography" include Fabien Hyafil, Klinikum Rechts der Isar, Munich, Germany, and Bichat University Hospital, Assistance Publique, Hôpitaux de Paris, Paris, France; Jaroslav Pelisek, Iina Laitinen, Miriam Mohring; Michael Kallmayer, Johannes Fischer, Christine Baumgartner, and Hans-Henning Eckstein, of Klinikum Rechts der Isar; Margret Schottelius, Katja Steiger, Andreas Poschenrieder, Johannes Notni, and Hans-Jürgen Wester, Technische Universität München, Garching, Germany; Yvonne Döring and Emiel P.C. van der Vorst, Ludwig-Maximilians-Universität München, Munich, Germany; Christian Weber, Ludwig-Maximilians-Universität München, Technische Universität München, Klinikum Rechts der Isar, DZHK partner site Munich Heart Alliance, and Maastricht University, The Netherlands; Christoph Rischpler, Stephan G. Nekolla, and Markus Schwaiger, Klinikum Rechts der Isar, Bichat University Hospital, Assistance Publique - Hôpitaux de Paris, Technische Universität München, Ludwig-Maximilians-Universität München, DZHK partner site Munich Heart Alliance.
This work was supported by the European Research Council Executive Agency through a Multimodal Molecular Imaging Advanced Research Grant (Grant number 294582), the Deutsche Forschungsgemeinschaft (SFB 824-B5 and SFB 1123-A1), and Deutsches Zentrum für Herz-Kreislauf Forschung through a high-risk, high-volume grant.
Please visit the SNMMI Media Center to view the PDF of the study, including images, and more information about molecular imaging and personalized medicine. To schedule an interview with the researchers, please contact Laurie Callahan at (703) 652-6773 or email@example.com. Current and past issues of The Journal of Nuclear Medicine can be found online at http://jnm.
About the Society of Nuclear Medicine and Molecular Imaging
The Society of Nuclear Medicine and Molecular Imaging (SNMMI) is an international scientific and medical organization dedicated to raising public awareness about nuclear medicine and molecular imaging, a vital element of today's medical practice that adds an additional dimension to diagnosis, changing the way common and devastating diseases are understood and treated and helping provide patients with the best health care possible.
SNMMI's more than 17,000 members set the standard for molecular imaging and nuclear medicine practice by creating guidelines, sharing information through journals and meetings and leading advocacy on key issues that affect molecular imaging and therapy research and practice. For more information, visit http://www.
Laurie Callahan | EurekAlert!
Traumas change perception in the long term
19.08.2019 | Rheinische Friedrich-Wilhelms-Universität Bonn
Stanford develops wireless sensors that stick to the skin to track our health
16.08.2019 | Stanford University
Soft robots have a distinct advantage over their rigid forebears: they can adapt to complex environments, handle fragile objects and interact safely with humans. Made from silicone, rubber or other stretchable polymers, they are ideal for use in rehabilitation exoskeletons and robotic clothing. Soft bio-inspired robots could one day be deployed to explore remote or dangerous environments.
Most soft robots are actuated by rigid, noisy pumps that push fluids into the machines' moving parts. Because they are connected to these bulky pumps by tubes,...
Researchers at TU Graz are working together with European partners on new possibilities of measuring vehicle emissions.
Today, air pollution is one of the biggest challenges facing European cities. As part of the Horizon 2020 research project CARES (City Air Remote Emission...
Over the next three years, researchers from the Vrije Universiteit Brussel, University of Cambridge, École Supérieure de Physique et de Chimie Industrielles de la ville de Paris (ESPCI-Paris) and Empa will be working together with the Dutch Polymer manufacturer SupraPolix on the next generation of robots: (soft) robots that ‘feel pain’ and heal themselves. The partners can count on 3 million Euro in support from the European Commission.
Soon robots will not only be found in factories and laboratories, but will be assisting us in our immediate environment. They will help us in the household, to...
Scientists at the University of Leeds have created a new form of gold which is just two atoms thick - the thinnest unsupported gold ever created.
The researchers measured the thickness of the gold to be 0.47 nanometres - that is one million times thinner than a human finger nail. The material is regarded...
An international team of scientists involving the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) in Hamburg has unraveled the light-induced electron-localization dynamics in transition metals at the attosecond timescale. The team investigated for the first time the many-body electron dynamics in transition metals before thermalization sets in. Their work has now appeared in Nature Physics.
The researchers from ETH Zurich (Switzerland), the MPSD (Germany), the Center for Computational Sciences of University of Tsukuba (Japan) and the Center for...
16.08.2019 | Event News
14.08.2019 | Event News
12.08.2019 | Event News
19.08.2019 | Information Technology
19.08.2019 | Physics and Astronomy
19.08.2019 | Life Sciences