***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: BACKGROUND AND PURPOSE : DLB is recognized as the second major form of dementia in the elderly . The regional pattern of GM atrophy in DLB highly overlaps that in AD . The aim of this study was to identify the critical pattern of atrophy in DLB by using DARTEL , which provides improved registration accuracy compared with that of conventional VBM . MATERIAL S AND METHODS : We evaluated 51 patients with probable AD , 43 patients with probable DLB , and 40 age-matched healthy controls . The pattern of GM atrophy in each group was compared by using conventional VBM and VBM-DARTEL . RESULTS : Regional patterns of atrophy identified by using conventional VBM differed significantly from those identified by using VBM-DARTEL . A decrease in GM volume in the MTLs in both AD and DLB was identified with VBM-DARTEL ; the decrease was greater in patients with AD than in those with DLB . Comparisons with healthy controls revealed that the WM volume of the whole brain was preserved in patients with DLB . In contrast , a severe bilateral decrease in WM in the MTLs was detected in patients with AD . CONCLUSIONS : VBM-DARTEL provided more accurate results , and it enabled the identification of more localized morphologic alterations than did conventional VBM . Analysis of WM preservation in DLB could help to differentiate this condition from AD Voxel-based morphometry ( VBM ) has already been applied to MRI scans of patients with Alzheimer 's disease ( AD ) . The results of these studies demonstrated atrophy of the hippocampus , temporal pole , and insula , but did not describe any global brain changes or atrophy of deep cerebral structures . We propose an optimized VBM method , which accounts for these shortcomings . Additional processing steps are incorporated in the method , to ensure that the whole spectrum of brain atrophy is visualized . A local group template was created to avoid registration bias , morphological opening was performed to eliminate cerebrospinal fluid voxel misclassifications , and volume preserving modulation was used to correct for local volume changes . Group differences were assessed and thresholded at P < 0.05 ( corrected ) . Our results confirm earlier findings , but additionally we demonstrate global cortical atrophy with sparing of the sensorimotor cortex , occipital poles , and cerebellum . Moreover , we show atrophy of the cau date head nuclei and medial thalami . Our findings are in full agreement with the established neuropathological descriptions , offering a comprehensive view of atrophy patterns in AD Increasing evidence demonstrates that there is marked damage and dysfunction in the white matter in Alzheimer ’s disease ( AD ) . The present study investigates the nature of white matter damage of patients with Alzheimer ’s disease with diffusion tensor magnetic resonance imaging ( DTI ) and analyses the relationship between the white matter damage and the cognition function . DTI , as well as T1 fluid attenuated inversion recovery ( FLAIR ) and T2-FLAIR , was performed on probable patients of Alzheimer ’s disease , and sex and age matched healthy volunteers to measure the fractional anisotropy ( FA ) and mean diffusivity ( MD ) in the genu and splenium of the corpus callosum , anterior and posterior limbs of the internal capsule , and the white matter of frontal , temporal , parietal , and occipital lobes . FA was lower in the splenium of corpus callosum , as well as in the white matter of the frontal , temporal , and parietal lobes from patients with Alzheimer ’s disease than in the corresponding region from healthy controls and was strongly positive correlated with MMSE scores , whereas FA appeared no different in the anterior and posterior limbs of internal capsule , occipital lobes white matter , and the genu of corpus callosum between the patients and healthy controls . MD was significantly higher in the splenium of corpus callosum and parietal lobes white matter from patients than in that those from healthy controls and was strongly negative correlated with MMSE scores , whereas MD in the anterior and posterior limbs of internal capsule , as well as in frontal , temporal , occipital lobes white matter and the genu of corpus callosum , was not different between the patients and healthy controls . The most prominent alteration of FA and MD was in the splenium of corpus callosum . Our results suggested that white matter of patients with Alzheimer ’s disease was selectively impaired and the extent of damage had a strong correlation with the cognitive function , and that selective impairment reflected the cortico – cortical and cortico – subcortical disconnections in the pathomechanism of Alzheimer ’s disease . The values of FA and MD in white matter , especially in the splenium of corpus callosum in AD patients , might be a more appropriate surrogate marker for monitoring the disease progression Introduction Our aim was to determine diffusion abnormalities in the uncinate fasciculus ( UF ) in Alzheimer ’s disease ( AD ) by diffusion tensor tractography ( DTT ) using a new method for measuring the core of the tract . Methods We studied 19 patients with AD and 19 age-matched control subjects who underwent MRI using diffusion tensor imaging ( DTI ) .  DTT of the UF was generated . The mean diffusivity ( MD ) and fractional anisotropy ( FA ) of the core of the tract were measured after voxelized tract shape processing . Student ’s t-test was used to compare results between patients with AD and controls . Intraobserver correlation tests were also performed . Results FA was significantly lower ( P < 0.0001 ) in the UF of patients with AD than of controls . There was no significant difference in MD along the UF between the two groups . Intraobserver reliability ( intraclass correlation coefficient ) for the first and second measurement was r > 0.93 for measured FA and r > 0.92 for measured MD . Conclusion Our results suggest that FA reflects progression of AD-related histopathological changes in the UF of the white matter and may represent a useful biological index in monitoring AD . Diffusion tensor tract-specific analysis with voxelized tract shape processing to measure the core of the tract may be a sensitive tool for evaluation of diffusion abnormalities of white matter tracts in AD We compared voxel-based morphometry ( VBM ) with independent accurate region-of-interest ( ROI ) measurements of temporal lobe structures in order to vali date the usefulness of this fully automated and unbiased technique in Alzheimer 's disease ( AD ) and semantic dementia ( SD ) . In AD , ROI analyses appear more sensitive to volume loss in the amygdalae , whereas VBM analyses appear more sensitive to right middle temporal gyrus and regional hippocampal volume loss . In SD , ROI analyses appear more sensitive to left middle and inferior temporal gyrus volume loss , whereas VBM appears more sensitive to regional hippocampal volume loss . In addition the significance of volume reductions was generally less in VBM owing to more stringent corrections for multiple comparisons . In conclusion , the automated technique detects a general trend of atrophy similar to that of expertly labeled ROI measurements in AD and SD , although there are discrepancies in the ranking of severity and in the significance of volume reductions that are more marked in AD 
    Output:
    
Significant reductions were observed in the left parahippocampal gyrus extending to the temporal white matter , the right temporal white matter extending to the parahippocampal gyrus and the posterior corpus callosum .
The findings remain largely unchanged in the jackknife sensitivity analyses .
White matter atrophy was clearly identified in AD , mainly in bilateral structures close to memory formations such as the hippocampus , amygdala , and entorhinal cortex