By applying the techniques to the newly completed dataset of the multi-institution Alzheimer's Disease Neuroimaging Initiative (ADNI), the scientists demonstrated that such sub-regional brain volume measurements outperform available measures for tracking severity of Alzheimer's disease, including widely used cognitive testing and measures of global brain-volume loss.
The general pattern of brain atrophy resulting from Alzheimer's disease has long been known through autopsy studies, but exploiting this knowledge toward accurate diagnosis and monitoring of the disease has only recently been made possible by improvements in computational algorithms that automate identification of brain structures with MRI. The new methods described in the study provide rapid identification of brain sub-regions combined with measures of change in these regions across time. The methods require at least two brain scans to be performed on the same MRI scanner over a period of several months. The new research shows that changes in the brain's memory regions, in particular a region of the temporal lobe called the entorhinal cortex, offer sensitive measures of the early stages of the disease.
"Loss of volume in the hippocampus is a consistent finding when using MRI, and is a reliable predictor of cognitive decline," said Anders M. Dale, PhD, professor of neurosciences and radiology at the UC San Diego School of Medicine, who led the study. "However, we have now developed and validated imaging biomarkers to not only track brain atrophy, but distinguish the early stages of Alzheimer's disease from changes related to normal aging."
The researchers at dozens of sites across the U.S. studied nearly 300 patients with mild cognitive impairment, 169 healthy controls and 129 subjects with AD and then measured rates of sub-regional cerebral volume change for each group. Power calculations were performed to identify regions that would provide the most sensitive outcome measures in clinical trials of disease-modifying agents.
"The technique is extremely powerful, because it allows a researcher to examine exactly how much brain-volume loss has occurred in each region of the brain, including cortical regions, where we know the bad proteins of Alzheimer's disease build up," said study co-author James Brewer, MD, PhD, a neurologist and assistant professor in the Departments of Radiology and Neurosciences at UC San Diego. "We are particularly excited to use the techniques in new clinical trials, but also to reexamine old clinical trial data where global measures of brain shrinkage were applied. These new findings suggest that such global measures are less sensitive than regional measures for detecting the changes specific to Alzheimer's disease – the changes these drugs are targeting."
Additional contributors to the study include Dominic Holland, Donald J. Hagler and Christine Fennema-Notestine of UC San Diego and members of the Alzheimer's Disease Neuroimaging Initiative. ADNI is funded in part by the National Institute on Aging and the National Institute of Biomedical Imaging and Bioengineering. Anders Dale is a founder and holds equity in CorTechs Labs, Inc, and also serves on its Scientific Advisory Board.
The five-year, $60 million Alzheimer's Disease Neuroimaging Initiative (ADNI), a landmark research study to identify brain and other biological changes associated with memory decline, was launched in 2004 by the National Institutes of Health (NIH). The project was begun by the National Institute on Aging (NIA) at the NIH and is supported by more than a dozen other federal agencies and private-sector companies and organizations, making it the largest public-private partnership on brain research underway at the NIH. Investigators at 58 sites across the United States and Canada are involved with the study. The goal of the initiative is to speed up the search for treatments and cures for Alzheimer's disease by seeing whether imaging of the brain – through magnetic resonance imaging (MRI) or positron emission tomography (PET) scans, together with other biomarkers – can help predict and monitor the onset and progression of Alzheimer's disease.
Debra Kain | EurekAlert!
New study: How does Europe become a leading player for software and IT services?
03.04.2017 | Fraunhofer-Institut für System- und Innovationsforschung (ISI)
Reusable carbon nanotubes could be the water filter of the future, says RIT study
30.03.2017 | Rochester Institute of Technology
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
28.04.2017 | Event News
20.04.2017 | Event News
18.04.2017 | Event News
28.04.2017 | Medical Engineering
28.04.2017 | Earth Sciences
28.04.2017 | Life Sciences