Researchers at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory have demonstrated a new, highly detailed x-ray imaging technique that could be developed into a method for early diagnosis of Alzheimer’s disease.
The technique has previously been used to look at tumors in breast tissue and cartilage in human knee and ankle joints, but this study is the first to test its ability to visualize a class of miniscule plaques that are a hallmark feature of Alzheimer’s disease. Their results will appear in a July 2009 edition of the journal NeuroImage.Images of the brain of a transgenic mouse obtained through histology and the corresponding brain region imaged with DEI in computed tomography mode.
Scientists have long known that Alzheimer’s disease is associated with plaques, areas of dense built-up proteins, in the affected brain. Many also believe that these plaques, called amyloid beta (Aß) plaques after the protein they contain, actually cause the disease. A major goal is to develop a drug that removes the plaques from the brain. However, before drug therapies can be tested, researchers need a non-invasive, safe, and cost-effective way to track the plaques’ number and size.
That is no easy task: Aß plaques are extremely small – on the micrometer scale, or one millionth of a meter. And conventional techniques such as computed tomography (CT) poorly distinguish between the plaques and other soft tissue such as cartilage or blood vessels.
“These plaques are very difficult to see, no matter how you try to image them,” said Dean Connor, a former postdoctoral researcher at Brookhaven Lab now working for the University of North Carolina. “Certain methods can visualize the plaque load, or overall number of plaques, which plays a role in clinical assessment and analysis of drug efficacy. But these methods cannot provide the resolution needed to show us the properties of individual Aß plaques.”
A technique developed at Brookhaven, called diffraction-enhanced imaging (DEI), might provide the extra imaging power researchers crave. DEI, which makes use of extremely bright beams of x-rays available at synchrotron sources such as Brookhaven’s National Synchrotron Light Source, is used to visualize not only bone, but also soft tissue in a way that is not possible using standard x-rays. In contrast to conventional sources, synchrotron x-ray beams are thousands of times more intense and extremely concentrated into a narrow beam. The result is typically a lower x-ray dose with a higher image quality.
In this study, researchers from Brookhaven and Stony Brook University used DEI in a high-resolution mode called micro-computed tomography to visualize individual plaques in a mouse-brain model of Alzheimer’s disease. The results not only revealed detailed images of the plaques, but also proved that DEI can be used on whole brains to visualize a wide range of anatomical structures without the use of a contrast agent.
The images are similar to those produced by high-resolution magnetic resonance imaging (MRI), with the potential to even exceed MRI pictures in resolution, Connor said. “The contrast and resolution we achieved in comparison to other types of imaging really is amazing,” he said. “When DEI is used, everything just lights up.”
The radiation dose used for this study is too high to safely image individual A• plaques in humans – the ultimate goal – but the results provide researchers with promising clues.
“Now that we know we can actually see these plaques, the hope is to develop an imaging modality that will work in living humans,” Connor said. “We’ve also now shown that we can see these plaques in a full brain, which means we can produce images from a live animal and learn how these plaques grow.”
Funding for this study was provided by the National Institutes of Health, the National Cancer Institute, and Brookhaven Lab’s Laboratory Directed Research and Development program. The National Synchrotron Light Source is funded by the Office of Basic Energy Sciences within the DOE Office of Science.How it works
The diffracted beam is passed onto a radiographic plate or digital recorder, which documents the differences in intensity to show the interior structural details.
Kendra Snyder | EurekAlert!
Europe’s Demographic Future. Where the Regions Are Heading after a Decade of Crises
10.08.2017 | Berlin-Institut für Bevölkerung und Entwicklung
Scientists reveal source of human heartbeat in 3-D
07.08.2017 | University of Manchester
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
23.08.2017 | Life Sciences
23.08.2017 | Life Sciences
23.08.2017 | Physics and Astronomy