Combining shape and connectivity analysis: An MRI study of thalamic degeneration in Alzheimer’s disease
NeuroImage. 2010-01-01; 49(1): 1-8
DOI: 10.1016/j.neuroimage.2009.09.001
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1. Neuroimage. 2010 Jan 1;49(1):1-8. doi: 10.1016/j.neuroimage.2009.09.001. Epub
2009 Sep 8.
Combining shape and connectivity analysis: an MRI study of thalamic degeneration
in Alzheimer’s disease.
Zarei M(1), Patenaude B, Damoiseaux J, Morgese C, Smith S, Matthews PM, Barkhof
F, Rombouts SA, Sanz-Arigita E, Jenkinson M.
Author information:
(1)FMRIB Centre, John Radcliffe Hospital, Oxford, UK.
Erratum in
Neuroimage. 2010 Jun;51(2):940. Rombouts, Serge [corrected to Rombouts, Serge A R
B].
Alzheimer’s disease (AD) is associated with neuronal loss not only in the
hippocampus and amygdala but also in the thalamus. Anterodorsal, centromedial,
and pulvinar nuclei are the main sites of degeneration in AD. Here we combined
shape analysis and diffusion tensor imaging (DTI) tractography to study
degeneration in AD in the thalamus and its connections. Structural and diffusion
tensor MRI scans were obtained from 16 AD patients and 22 demographically similar
healthy volunteers. The thalamus, hippocampus, and amygdala were automatically
segmented using our locally developed algorithm, and group comparisons were
carried out for each surface vertex. We also employed probabilistic diffusion
tractography to obtain connectivity measures between individual thalamic voxels
and hippocampus/amygdala voxels and to segment the internal medullary lamina
(IML). Shape analysis showed significant bilateral regional atrophy in the
dorsal-medial part of the thalamus in AD patients compared to controls.
Probabilistic tractography demonstrated that these regions are mainly connected
with the hippocampus, temporal, and prefrontal cortex. Intrathalamic FA
comparisons showed reductions in the anterodorsal region of thalamus.
Intrathalamic tractography from this region revealed that the IML was
significantly smaller in AD patients than in controls. We suggest that these
changes can be attributed to the degeneration of the anterodorsal and
intralaminar nuclei, respectively. In addition, based on previous
neuropathological reports, ventral and dorsal-medial shape change in the thalamus
in AD patients is likely to be driven by IML atrophy. This combined shape and
connectivity analysis provides MRI evidence of regional thalamic degeneration in
AD.
DOI: 10.1016/j.neuroimage.2009.09.001
PMID: 19744568 [Indexed for MEDLINE]