NeuroImage. Clinical
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NeuroImage. Clinical · Jan 2013
OASIS is Automated Statistical Inference for Segmentation, with applications to multiple sclerosis lesion segmentation in MRI.
Magnetic resonance imaging (MRI) can be used to detect lesions in the brains of multiple sclerosis (MS) patients and is essential for diagnosing the disease and monitoring its progression. In practice, lesion load is often quantified by either manual or semi-automated segmentation of MRI, which is time-consuming, costly, and associated with large inter- and intra-observer variability. We propose OASIS is Automated Statistical Inference for Segmentation (OASIS), an automated statistical method for segmenting MS lesions in MRI studies. ⋯ OASIS obtains the estimated probability for each voxel to be part of a lesion by weighting each imaging modality with coefficient weights. These coefficients are explicit, obtained using standard model fitting techniques, and can be reused in other imaging studies. This fully automated method allows sensitive and specific detection of lesion presence and may be rapidly applied to large collections of images.
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NeuroImage. Clinical · Jan 2013
Altered brain morphometry in carpal tunnel syndrome is associated with median nerve pathology.
Carpal tunnel syndrome (CTS) is a common median nerve entrapment neuropathy characterized by pain, paresthesias, diminished peripheral nerve conduction velocity (NCV) and maladaptive functional brain neuroplasticity. We evaluated structural reorganization in brain gray (GM) and white (WM) matter and whether such plasticity is linked to altered median nerve function in CTS. ⋯ Our study identified clear morphometric changes in the CTS brain. This central morphometric change is likely secondary to peripheral nerve pathology and altered somatosensory afference. Enhanced axonal coherence and myelination within cortico-cortical tracts connecting primary somatosensory and motor areas may accompany peripheral nerve deafferentation. As structural plasticity was correlated with NCV and not symptomatology, the former may be a better determinant of appropriate clinical intervention for CTS, including surgery.
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NeuroImage. Clinical · Jan 2013
An investigation of changes in regional gray matter volume in cardiovascular disease patients, pre and post cardiovascular rehabilitation.
Cognitive function decline secondary to cardiovascular disease has been reported. However, little is known about the impact of coronary artery disease (CAD) on the aging brain macrostructure or whether exercise training, in the context of cardiovascular rehabilitation, can affect brain structure following a coronary event. This study employed voxel-based morphometry of high resolution structural MRI images to investigate; 1) changes in regional gray matter volume (GMV) in CAD patients compared to age-matched controls, and 2) the effects of a six-month exercise-based cardiovascular rehabilitation program on CAD-related GMV decline. ⋯ Cardiovascular rehabilitation was associated with the recovery of regional GMV in the superior frontal gyrus, superior temporal gyrus and posterior cerebellum of the CAD patients as well as the increase in GMV in the supplementary motor area. Total and regional GMV correlated with fitness level, defined by the maximal oxygen consumption (VO2max), at baseline but not after cardiovascular rehabilitation. This study demonstrates that cardiovascular disease can adversely affect age-related decline in GMV; and that these disease-related effects could be mitigated by moderate levels of exercise training as part of cardiovascular rehabilitation.
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NeuroImage. Clinical · Jan 2013
Late-life depression, mild cognitive impairment and hippocampal functional network architecture.
Late-life depression (LLD) and amnestic mild cognitive impairment (aMCI) are associated with medial temporal lobe structural abnormalities. However, the hippocampal functional connectivity (HFC) similarities and differences related to these syndromes when they occur alone or coexist are unclear. Resting-state functional connectivity MRI (R-fMRI) technique was used to measure left and right HFC in 72 elderly participants (LLD [n = 18], aMCI [n = 17], LLD with comorbid aMCI [n = 12], and healthy controls [n = 25]). ⋯ In conclusion, these findings indicate that discrete hippocampal functional network abnormalities are associated with LLD and aMCI when they occur alone. However, when these conditions coexist, more pronounced vulnerabilities of the hippocampal networks occur, which may be a marker of disease severity and impending cognitive decline. By utilizing R-fMRI technique, this study provides novel insights into the neural mechanisms underlying LLD and aMCI in the functional network level.
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NeuroImage. Clinical · Jan 2013
Deficits in cortical, diencephalic and midbrain gray matter in alcoholism measured by VBM: Effects of co-morbid substance abuse.
Alcoholism has been associated with a widespread pattern of gray matter atrophy. This study sought to investigate the spectrum of volume alterations in a population of alcoholics with only alcohol dependence, polysubstance abusing alcoholics, and a comparison population of healthy controls. ⋯ These findings reinforce the accepted literature in regards to frontal lobe gray matter atrophy in alcohol dependence. This study calls for additional research in order to investigate the spectrum from uncomplicated alcoholism to Wernicke-Korsakoff Syndrome. Further research is needed to elucidate the exact cause of this pattern of differences and to determine what factors are responsible for the patterns of gray matter reduction or difference in 'pure' and polysubstance abusing alcoholics.