104 research outputs found
nibabel 1.2.0
No full text<p>This release had large contributions from Krish Subramaniam, Alexandre Gramfort, Cindee Madison, Félix C. Morency and Christian Haselgrove.</p>
<ul>
<li>New feature and bugfix release</li>
<li>Freesurfer format support by Krish Subramaniam and Alexandre Gramfort.</li>
<li>ECAT read write support by Cindee Madison and Félix C. Morency.</li>
<li>A DICOM fuse filesystem by Christian Haselgrove.</li>
<li>Much work on making data scaling on read and write more robust to rounding error and overflow (MB).</li>
<li>Import of nipy functions for working with affine transformation matrices.</li>
<li>Added methods for working with nifti sform and qform fields by Bago Amirbekian and MB, with useful discussion by Brendan Moloney.</li>
<li>Fixes to read / write of RGB analyze images by Bago Amirbekian.</li>
<li>Extensions to concat_images by Yannick Schwartz.</li>
<li>A new nib-ls script to display information about neuroimaging files, and various other useful fixes by Yaroslav Halchenko.</li>
</ul>
P2–129: Region‐specific associations of brain glucose metabolism with age and beta‐amyloid deposition in normal aging
No full textO4–09–05: Association of gray matter atrophy with age, beta‐amyloid, white matter hyperintensity and cognition in normal aging
No full textDynamic relationships between age, amyloid-β deposition, and glucose metabolism link to the regional vulnerability to Alzheimer’s disease
No full textSEE HANSSON AND GOURAS DOI101093/AWW146 FOR A SCIENTIFIC COMMENTARY ON THIS ARTICLE: Although some brain regions such as precuneus and lateral temporo-parietal cortex have been shown to be more vulnerable to Alzheimer's disease than other areas, a mechanism underlying the differential regional vulnerability to Alzheimer's disease remains to be elucidated. Using fluorodeoxyglucose and Pittsburgh compound B positron emission tomography imaging glucose metabolism and amyloid-β deposition, we tested whether and how life-long changes in glucose metabolism relate to amyloid-β deposition and Alzheimer's disease-related hypometabolism. Nine healthy young adults (age range: 20-30), 96 cognitively normal older adults (age range: 61-96), and 20 patients with Alzheimer's disease (age range: 50-90) were scanned using fluorodeoxyglucose and Pittsburgh compound B positron emission tomography. Among cognitively normal older subjects, 32 were further classified as amyloid-positive, with 64 as amyloid-negative. To assess the contribution of glucose metabolism to the regional vulnerability to amyloid-β deposition, we defined the highest and lowest metabolic regions in young adults and examined differences in amyloid deposition between these regions across groups. Two-way analyses of variance were conducted to assess regional differences in age and amyloid-β-related changes in glucose metabolism. Multiple regressions were applied to examine the association between amyloid-β deposition and regional glucose metabolism. Both region of interest and whole-brain voxelwise analyses were conducted to complement and confirm the results derived from the other approach. Regional differences in glucose metabolism between the highest and lowest metabolism regions defined in young adults (T = 12.85, P < 0.001) were maintained both in Pittsburgh compound B-negative cognitively normal older subjects (T = 6.66, P < 0.001) and Pittsburgh compound B-positive cognitively normal older subjects (T = 10.62, P < 0.001), but, only the Pittsburgh compound B-positive cognitively normal older subjects group showed significantly higher Pittsburgh compound B retention in the highest compared to the lowest glucose metabolism regions defined in young adults (T = 2.05, P < 0.05). Regional differences in age and amyloid-β-dependent changes in glucose metabolism were found such that frontal glucose metabolism was reduced with age, while glucose metabolism in the precuneus was maintained across the lifespan (right hemisphere: F = 7.69, P < 0.001; left hemisphere: F = 8.69, P < 0.001). Greater Alzheimer's disease-related hypometabolism was observed in brain regions that showed both age-invariance and amyloid-β-related increases in glucose metabolism. Our results indicate that although early and life-long regional variation in glucose metabolism relates to the regional vulnerability to amyloid-β accumulation, Alzheimer's disease-related hypometabolism is more specific to brain regions showing age-invariant glucose metabolism and amyloid-β-related hypermetabolism
IC‐P‐195: Region‐specific associations of brain glucose metabolism with age and beta‐amyloid in normal aging
No full textDynamic relationships between age, amyloid-β deposition, and glucose metabolism link to the regional vulnerability to Alzheimer’s disease
No full textSubjective cognition and amyloid deposition imaging: a Pittsburgh Compound B positron emission tomography study in normal elderly individuals.
No full textInternational audienceOBJECTIVE: To study the relationship between subjective cognition and the neuropathological hallmark of Alzheimer disease (AD), amyloid-β (Aβ) deposition, using carbon 11-labeled Pittsburgh Compound B (PiB) positron emission tomography in normal elderly individuals. DESIGN: Cross-sectional analysis. SUBJECTS: Forty-eight cognitively normal elderly subjects (11 with high PiB uptake and 28 with low PiB uptake) were included. All underwent clinical and neuropsychological evaluations, magnetic resonance imaging, and positron emission tomography. SETTING: Berkeley Aging Cohort Study. MAIN OUTCOME MEASURE: Relationship between PiB uptake and subjective cognition measures. RESULTS: Subjects with high PiB uptake showed significantly lower performance than those with low PiB uptake on an episodic memory measure and were less confident about their general memory abilities when required to evaluate themselves relative to other people of the same age. High and low PiB uptake groups did not differ on the accuracy of their cognitive self-reports compared with objective cognitive performance. General memory self-reports from the whole group were significantly correlated with regional PiB uptake in the right medial prefrontal cortex and anterior cingulate cortex and in the right precuneus and posterior cingulate cortex. Reduced confidence about memory abilities was associated with greater PiB uptake in these brain regions. All results were independent of demographic variables and depressive affects. CONCLUSIONS: A decrease of self-confidence about memory abilities in cognitively normal elderly subjects may be related to the neuropathological hallmark of AD measured with PiB-positron emission tomography. Subjective cognitive impairment may represent a very early clinical manifestation of AD
P2–131: Relationships between cognitive activity, Alzheimer's disease pathological biomarkers and cognitive functioning in normal older adults
No full text- …
