Whole-body PET scan with new imaging agent can locate hidden blood clots
Finding location, composition of clots can provide information crucial for diagnosis, prevention of strokes, other conditions
(Press-News.org) A novel radiopharmaceutical probe developed at Massachusetts General Hospital (MGH) has the potential of providing physicians with information that could save the lives of patients with ischemic stroke or pulmonary embolism - conditions caused when important blood vessels are blocked by a clot that has traveled from another part of the body. In a report that will appear in the October issue of the journal Arteriosclerosis, Thrombosis and Vascular Biology and has been published online, the MGH team describes using this new probe to conduct full-body scans in an animal model. Preliminary results also were reported earlier this year at the national meeting of the American Chemical Society.
"We found that, with a single intravenous injection of our clot-finding probe 64Cu-FBP8, we were able to detect blood clots anywhere in the body using a positron emission tomography (PET) scan," says lead author Francesco Blasi, PharmD, PhD, formerly a research fellow at the Martinos Center for Biomedical Imaging at MGH and now at the University of Torino in Italy. "We also found that the probe may be able to distinguish recently formed clots from older ones - which can indicate the likelihood that a particular clot is the source the clot causing a stroke or pulmonary embolism - and reveal the composition of a clot, which can determine whether it will respond to clot-dissolving treatments."
The authors note that, although blood clots are a leading cause of illness and death, current imaging techniques for identifying the presence and location of clots only work for particular areas of the body; none is useful for all of the regions from which a clot can originate. Standard practice for identifying the source of a clot that causes a stroke may involve multiple imaging studies - ultrasound, echocardiography, MR or CT angiography - that can be both expensive and time consuming, possibly delaying the use of therapies to prevent a second stroke. Study leader Peter Caravan, PhD, of the Martinos Center and his colleagues have developed several PET imaging agents that target the protein fibrin, which is generated as part of the process of clot formation; and 64Cu-FBP8 appeared to be the most promising.
To test the probe's ability to find clots anywhere in the body, the investigators induced the formation of clots in the carotid arteries and the femoral veins of a group of rats. Whole-body imaging studies combining 64Cu-FBP8 PET and CT scanning were conducted either one, three or seven days after clot formation. The team members reading the images, who had not been informed of the precise locations where clots had been induced, accurately detected the locations 97 percent of the time. The intensity of the signal generated by 64Cu-FBP8 decreased with the age of the clot and with the amount of fibrin it contained, as confirmed by pathologic analysis. Caravan notes that, because older clots are more stable, they are less likely to be the source of a clot that caused a stroke. Since clot-dissolving drugs act by targeting fibrin, younger fibrin-rich clots are better candidates for treatment with those agents, the use of which needs to be balanced against the risk of bleeding.
"A clot causing a stroke can arise in the arteries of the neck, from the aorta in the chest, from within the heart or from veins deep within the legs; and knowing if any clot remains at those locations is important because it indicates a higher risk of a second stroke. The patient may be treated differently if that parent clot is still present than if no clot remains," says Caravan, who is an associate professor of Radiology at Harvard Medical School and co-director of the Institute for Innovation in Imaging at MGH. "A whole-body technique could also determine whether a patient's shortness of breath is caused by a pulmonary embolism and identify both the source and the extent of the parent clot in the deep veins."
Caravan and his colleagues will soon be testing 64Cu-FBP8 in human volunteers to better understand how the probe is distributed through the body and how long it remains after injection, information essential to designing studies of its diagnostic effectiveness in patients. Patent rights for the fibrin-binding peptide used in 64Cu-FBP8 have been licensed to Factor 1A, a company co-founded by Caravan. The current study was supported by National Heart, Lung and Blood Institute grant HL109448.
Additional co-authors of the Arteriosclerosis, Thrombosis and Vascular Biology paper are Bruno Oliveira, PhD, Tyson Reitz, Nicholas Rotile, David Izquierdo-Garcia, PhD, and Ciprian Catana, MD, Martinos Center; and Pratap Naha, PhD, and David Cormode, PhD, Perelman School of Medicine, University of Pennsylvania.
Massachusetts General Hospital, founded in 1811, is the original and largest teaching hospital of Harvard Medical School. The MGH conducts the largest hospital-based research program in the United States, with an annual research budget of more than $760 million and major research centers in AIDS, cardiovascular research, cancer, computational and integrative biology, cutaneous biology, human genetics, medical imaging, neurodegenerative disorders, regenerative medicine, reproductive biology, systems biology, transplantation biology and photomedicine. In July 2015, MGH returned into the number one spot on the 2015-16 U.S. News & World Report list of "America's Best Hospitals."
ELSE PRESS RELEASES FROM THIS DATE:
PITTSBURGH, Sept. 15, 2015 - Nearly 1 in 5 recently surveyed high school seniors report having smoked tobacco from a hookah in the past year, and more than a third of them reported smoking hookahs often enough to be considered regular users, an analysis led by the University of Pittsburgh Center for Research on Media, Technology, and Health (CRMTH) revealed.
The findings, published online and scheduled for a coming print issue of the American Journal of Preventive Medicine, add to evidence that hookah use among adolescents is increasing in both prevalence and frequency. ...
In recent years, there has been an increase in emergence and use of a variety of new drugs, so-called "novel psychoactive substances" (NPS) in the US and worldwide. However, there is little published survey data estimating the prevalence of use in the US. Media reports about use of new drugs such as "Spice" ("synthetic marijuana") and "bath salts" such as "Flakka" are now common, yet very few health surveys ask about use of such drugs.
A new study, published in Drug and Alcohol Dependence by researchers affiliated with New York University's Center for Drug Use and HIV ...
Montreal, September 15, 2015 -- With the federal election around the corner, child care has become a major ballot issue. While every party has its own idea of how best to offset the costs of raising children, no one is looking at how we perceive and value those who provide the education and care.
Concordia researcher Sandra Chang-Kredl wants that to change. In a paper recently published in the Journal of Media & Cultural Studies, she writes that "invariably, the focus of the debate is on the children's needs, the parents' needs and society's needs. The educator is rarely ...
DURHAM, N.C. -- Energy companies used nearly 250 billion gallons of water to extract unconventional shale gas and oil from hydraulically fractured wells in the United States between 2005 and 2014, a new Duke University study finds.
During the same period, the fracked wells generated about 210 billion gallons of wastewater.
Large though those numbers seem, the study calculates that the water used in fracking makes up less than 1 percent of total industrial water use nationwide.
While fracking an unconventional shale gas or oil well takes much more water than drilling ...
In what is believed to be the largest, most detailed study of its kind in the United States, scientists at NYU Langone Medical Center and elsewhere have confirmed that tiny chemical particles in the air we breathe are linked to an overall increase in risk of death.
The researchers say this kind of air pollution involves particles so small they are invisible to the human eye (at less than one ten-thousandth of an inch in diameter, or no more than 2.5 micrometers across).
In a report on the findings, published in the journal Environmental Health Perspectives online Sept. ...
Fetuses with enlarged ventricles--the fluid-filled cavities inside the brain--may be less likely than other fetuses to benefit from surgery in the womb to treat spina bifida, according to a study co-authored by researchers at UCSF Benioff Children's Hospital San Francisco.
The researchers found that fetuses with enlarged ventricles were more likely to require a second surgery to relieve a life-threatening build-up of pressure within the brain. Given the risks that fetal surgery poses for mother and newborn, the findings indicate that in these cases, it may be better ...
Sydney, Australia -- Creating futuristic, next generation materials called 'metallic glass' that are ultra-strong and ultra-flexible will become easier and cheaper, based on UNSW Australia research that can predict for the first time which combinations of metals will best form these useful materials.
Just like something from science fiction - think of the Liquid-Metal Man robot assassin (T-1000) in the Terminator films - these materials behave more like glass or plastic than metal.
While still being metals, they become as malleable as chewing gum when heated and can ...
BERKELEY -- A new study by University of California, Berkeley, researchers establishes for the first time a link between infection with the bovine leukemia virus and human breast cancer.
In the study, published this month in the journal PLOS ONE and available online, researchers analyzed breast tissue from 239 women, comparing samples from women who had breast cancer with women who had no history of the disease for the presence of bovine leukemia virus (BLV). They found that 59 percent of breast cancer samples had evidence of exposure to BLV, as determined by the presence ...
Planning conservation actions requires up-to-date information on
Biodiversity is diminishing at unprecedented rates, and quick decisions are needed in what and where to protect.
"The decisions should be based on comprehensive information, but scientists do not have enough resources to collect more data and effectively monitor all species and habitats that need protection. As human are the main driving force of global change, conservation also needs information on human presence and behaviour" says Enrico Di Minin, a researcher in conservation science at the Department ...
A new study has found increasing support in the United States and Canada for smokefree laws for outdoor areas, especially in playgrounds and school grounds.
The collaborative study between the University of Otago, New Zealand and University of Alberta, Canada, provides new and some unexpected insights for health promotion in North America. A key finding is that most residents welcome smokefree laws. Support was strongest for smokefree playgrounds and school grounds, but there was also majority support for a range of other smokefree areas.
University of Otago, Wellington ...
LAST 30 PRESS RELEASES: