Diffusion tensor trace mapping in normal adult brain using single-shot epi technique: A methodological study of the aging brain

Zg, Chen; Tq, Li; Hindmarsh, T

doi:10.1080/028418501127347160

Cited by 12 publications

(10 citation statements)

References 28 publications

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“…For example, ! D1 is generally higher, particularly frontally, than in previously published cohorts, which used hospital-based [14] or younger [12,13,30] subjects. This is consistent with changes described with increasing age.…”

Section: Discussioncontrasting

confidence: 41%

See 1 more Smart Citation

Cognitive Correlates of Cerebral White Matter Lesions and Water Diffusion Tensor Parameters in Community-Dwelling Older People

Shenkin¹,

Bastin²,

MacGillivray

et al. 2005

Cerebrovasc Dis

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Section: Discussioncontrasting

confidence: 41%

“…D1 increases and FA decreases with age [12][13][14][15][16][17] . These changes occur in normal ageing, in parallel with changes in cognition, and therefore provide a plausible biological explanation for cognitive ageing [1,2] .…”

mentioning

confidence: 99%

Cognitive Correlates of Cerebral White Matter Lesions and Water Diffusion Tensor Parameters in Community-Dwelling Older People

Shenkin¹,

Bastin²,

MacGillivray

et al. 2005

Cerebrovasc Dis

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“…As observed postmortem, a predilection of age-related loss occurs for thin, unmyelinated fibers, which are in greatest abundance in the frontal lobes (Aboitiz et al, 1996;Bartzokis, 2004). Commonly but not necessarily, diffusivity negatively correlates with anisotropy within white matter samples (Chen et al, 2001;Engelter et al, 2000;Head et al, 2004;Helenius et al, 2002;Naganawa et al, 2003;Pfefferbaum et al, 2005;Sullivan, 2005b, 2003), probably reflecting an age-related increase in unbound interstitial fluid (e.g., Norris et al, 1994;Peters and Sethares, 2003;Pfefferbaum and Sullivan, 2005b;Rumpel et al, 1998;Sehy et al, 2002;Silva et al, 2002). Signal loss attributable to iron deposition is especially conspicuous on diffusion-weighted spin-echo images (Hiwatashi et al, 2003).…”

Section: Introductionmentioning

confidence: 84%

Diffusion tensor imaging of deep gray matter brain structures: Effects of age and iron concentration

Pfefferbaum

Adalsteinsson

Rohlfing

et al. 2010

Neurobiology of Aging

168

169

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Diffusion tensor imaging (DTI) of the brain has become a mainstay in the study of normal aging of white matter, and only recently has attention turned to the use of DTI to examine aging effects in gray matter structures. Of the many changes in the brain that occur with advancing age is increased presence of iron, notable in selective deep gray matter structures. In vivo detection and measurement of iron deposition is possible with magnetic resonance imaging (MRI) because of iron's effect on signal intensity. In the process of a DTI study, a series of diffusion-weighted images (DWI) is collected, and while not normally considered as a major dependent variable in research studies, they are used clinically and they reveal striking conspicuity of the globus pallidus and putamen caused by signal loss in these structures, presumably due to iron accumulation with age. These iron deposits may in turn influence DTI metrics, especially of deep gray matter structures. The combined imaging modality approach has not been previously used in the study of normal aging. The present study used legacy DTI data collected in 10 younger (22-37 years) and 10 older (65-79 years) men and women at 3.0 T and fast spin-echo (FSE) data collected at 1.5 T and 3.0 T to derive an estimate of the fielddependent relaxation rate increase (the "FDRI estimate") in the putamen, caudate nucleus, globus pallidus, thalamus, and a frontal white matter sample comparison region. The effect of age on the diffusion measures in the deep gray matter structures was distinctly different from that reported in white matter. In contrast to lower anisotropy and higher diffusivity typical in white matter of older relative to younger adults observed with DTI, both anisotropy and diffusivity were higher in the older than younger group in the caudate nucleus and putamen; the thalamus showed little effect of age on anisotropy or diffusivity. Signal intensity measured with DWI was lower in the putamen of elderly than young adults, whereas the opposite was observed for the white matter region and thalamus. As a retrospective study based on legacy data, the FDRI estimates were based on FSE sequences, which underestimated the classical FDRI index of brain iron. Nonetheless, the differential effects of age on DTI metrics in subcortical gray matter structures compared with white matter tracts appears to be related, at least in part, to local iron content, which in the elderly of the present study was prominent

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“…Regardless of approach, the general consensus is that with advancing age, anisotropy in white matter declines and is accompanied by an increase in diffusivity (Chun et al, 2000;Head et al, 2004;Madden et al, 2004;Nusbaum et al, 2001;O'Sullivan et al, 2001;Pfefferbaum and Sullivan, 2003;Pfefferbaum et al, 2000b;Salat et al, 2005;Stebbins et al, 2001; but see Chepuri et al, 2002;Helenius et al, 2002). The age effects are regionally diverse and typically show an anterior-posterior gradient of anisotropy decline (Ardekani et al, 2007;Bhagat and Beaulieu, 2004;Bucur et al, 2007;Foong et al, 2000;Grieve et al, 2007;Head et al, 2004;Hsu et al, 2008;Kochunov et al, 2007;Madden et al, 2004Madden et al, , 2007Nusbaum et al, 2001;O'Sullivan et al, 2001;Pfefferbaum et al, 2000bPfefferbaum et al, , 2005 ; Pfefferbaum and Sullivan, 2003;Salat et al, 2005;Sullivan et al, 2001;Takahashi et al, 2004;Yoon et al, 2007) and diffusivity rise (Chen et al, 2001;Engelter et al, 2000;Head et al, 2004;Helenius et al, 2002;Hsu et al, 2008;Naganawa et al, 2003;Pfefferbaum et al, 2005;Pfefferbaum and Sullivan, 2003) with age that was confirmed in a monkey model o...…”

Section: Introductionmentioning

confidence: 95%

Quantitative fiber tracking of lateral and interhemispheric white matter systems in normal aging: Relations to timed performance

Sullivan

Rohlfing

Pfefferbaum

2010

Neurobiology of Aging

310

307

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The integrity of white matter, as measured in vivo with diffusion tensor imaging (DTI), is disrupted in normal aging. A current consensus is that in adults advancing age affects anterior brain regions disproportionately more than posterior regions; however, the mainstay of studies supporting this anterior-posterior gradient is based primarily on measures of the corpus callosum. Using our quantitative fiber tracking approach, we assessed fiber tract integrity of samples of major white matter cortical, subcortical, interhemispheric, and cerebellar systems (11 bilateral and 2 callosal) on DTI data collected at 1.5 T magnet strength. Participants were 55 men (age 20-78 years) and 65 women (age 28-81 years), deemed healthy and cognitively intact following interview and behavioral testing. Fiber integrity was measured as orientational diffusion coherence (fractional anisotropy, FA) and magnitude of diffusion, which was quantified separately for longitudinal diffusivity (λL), an index of axonal length or number, and transverse diffusivity (λT), an index of myelin integrity. Aging effects were more evident in diffusivity than FA measures. Men and women, examined separately, showed similar age-related increases in longitudinal and transverse diffusivity in fibers of the internal and external capsules bilaterally and the fornix. FA was lower and diffusivity higher in anterior than posterior fibers of regional paired comparisons (genu versus splenium and frontal versus occipital forceps). Diffusivity with older age was generally greater or FA lower in the superior than inferior fiber systems (longitudinal fasciculi, cingulate bundles), with little to no evidence for age-related degradation in pontine or cerebellar systems. The most striking sex difference emerged for the corpus callosum, for which men showed significant decline in FA and increase in longitudinal and transverse diffusivity in the genu but not splenium. By contrast, in women the age effect was present in both callosal regions, albeit modestly more so in the genu than splenium. Functional meaningfulness of these age-related differences was supported by significant correlations between DTI signs of white matter degradation and poorer performance on cognitive or motor tests. This survey of multiple fiber systems throughout the brain revealed a differential pattern of age's effect on regional FA and diffusivity and suggests mechanisms of functional degradation, attributed at least in part to compromised fiber microstructure affecting myelin and axonal morphology.

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Diffusion tensor trace mapping in normal adult brain using single-shot epi technique: A methodological study of the aging brain

Cited by 12 publications

References 28 publications

Cognitive Correlates of Cerebral White Matter Lesions and Water Diffusion Tensor Parameters in Community-Dwelling Older People

Cognitive Correlates of Cerebral White Matter Lesions and Water Diffusion Tensor Parameters in Community-Dwelling Older People

Diffusion tensor imaging of deep gray matter brain structures: Effects of age and iron concentration

Quantitative fiber tracking of lateral and interhemispheric white matter systems in normal aging: Relations to timed performance

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