Analyzing Structural Brain Changes in Alzheimer's Disease
ScienceDaily (Nov. 23, 2009) — In a study that promises to improve diagnosis
and monitoring of Alzheimer's disease, scientists at the University of
California, San Diego have developed a fast and accurate method for
quantifying subtle, sub-regional brain volume loss using magnetic resonance
imaging (MRI).
利用微小區域性的大腦容量的痿縮，UCSD的科學家們發展出一個快且準確的方法
，改進診斷與監測阿茲海默症。
The study will be published the week of November 16 in the Proceedings of the
National Academy of Sciences (PNAS).
這研究會在11/16的PNAS中刊出。
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.
這個技術應用在新完成的ADNI(Alzheimer's Disease Neuroimaging Initiative)，科學
家們展示區域性的大腦容積是可以區隔出阿茲海默症。ADNI包涵廣泛使用的認知測驗以及
全腦容積痿縮。
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.
從對屍體的解剖可以知道大腦的痿縮是阿茲海默症的症狀。但利用這個概念做更準確的診
斷與監控，只有最近可自動化圈出大腦結構的演算法提出才變得可能。新方法可提供大量
區域性的辨識也可以量測隨著時間產生的變化。這種方法需要兩次以上不同時間的腦結構
影像，最好是相距幾個月。這研究顯示，大腦記憶區域特別是顳葉的entorhinal cortex的
變化，可以提供早期的疾病診斷。
"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."
"利用MRI發現海馬迴的容積減少是很一致的，對認知衰弱是一個可信任的預測者。"
Anders M. Dale表示。"然而，我們發展了一套有效的影像標誌不僅可以追蹤大腦痿縮，
也可以早期區分阿茲海默症以及年齡的影響。"
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.
研究者分佈在US的很多地方，收集了300個輕微認知功能喪失者、169個正常人以及
129個阿茲海默病患，去量測每組的區域性大腦容積改變。利用大量的運算去指出哪個地方
會在臨床試驗中給予病程改變藥物之下有最敏感的結果。
"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."
"這個技術是強而有力的，它讓研究者可以準確的檢視腦中的各區域容積如何減少，包含
皮質區，這裡我們知道有不好的蛋白質讓阿茲海默症增強。"James Brewer說。"我們特別
的興奮去使用這新的技術在新的臨床試驗中，但也可以重新審視舊的臨床試驗的資料，當
時是量測全腦的痿縮。這個新的發現指出舊的全腦量測對阿茲海默症以及藥物目標區域造
成的改變比較沒有敏感度"
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.
About ADNI
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.
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有翻錯請指正囉。
原網址：
http://www.sciencedaily.com/releases/2009/11/091116165737.htm
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