Objective: To use diffusion tensor imaging (DTI) to assess gray matter and white matter tract diffusion in behavioral variant frontotemporal dementia (bvFTD), semantic dementia (SMD), and progressive nonfluent aphasia (PNFA). Methods:This was a case-control study where 16 subjects with bvFTD, 7 with PNFA, and 4 with SMD were identified and matched by age and gender to 19 controls. All subjects had 3-T head MRI with a DTI sequence with diffusion encoding in 21 directions. Gray matter mean diffusivity (MD) was assessed using a region-of-interest (ROI) and voxel-level approach, and voxel-based morphometry was used to assess patterns of gray matter loss. White matter tract diffusivity (fractional anisotropy and radial diffusivity) was assessed by placing ROIs on tracts of interest. Results:In bvFTD, increased gray matter MD and gray matter loss were identified bilaterally throughout frontal and temporal lobes, with abnormal diffusivity observed in white matter tracts that connect to these regions. In SMD, gray matter loss and increased MD were identified predominantly in the left temporal lobe, with tract abnormalities observed in the inferior longitudinal fasciculus and uncinate fasciculus. In PNFA, gray matter loss and increased MD were observed in left inferior frontal lobe, insula, and supplemental motor area, with tract abnormalities observed in the superior longitudinal fasciculus. Conclusions:The diffusivity of gray matter is increased in regions that are atrophic in frontotemporal dementia, suggesting disruption of the cytoarchitecture of remaining tissue. Furthermore, damage was identified in white matter tracts that interconnect these regions, supporting the hypothesis that these diseases involve different and specific brain networks. Neurology ® 2010;74:1279 -1287 GLOSSARY AAL ϭ automated anatomic labeling; AC ϭ anterior cingulate; ADRC ϭ Alzheimer's Disease Research Center; ADPR ϭ Alzheimer's Disease Patient Registry; AOS ϭ apraxia of speech; bvFTD ϭ behavioral variant frontotemporal dementia; CV ϭ coefficient of variation; DA ϭ axial diffusivity; DR ϭ radial diffusivity; DTI ϭ diffusion tensor imaging; FA ϭ fractional anisotropy; FDR ϭ false discovery rate; FOV ϭ field of view; FTD ϭ frontotemporal dementia; FWHM ϭ full-width at half-maximum; GCC ϭ genu of the corpus callosum; HDW ϭ high-dimensional warping; ILF ϭ inferior longitudinal fasciculus; MD ϭ mean diffusivity; MPRAGE ϭ magnetization prepared rapid acquisition gradient echo; PC ϭ posterior cingulate; PNFA ϭ progressive nonfluent aphasia; PVC ϭ partial volume correction; ROI ϭ region of interest; SLF ϭ superior longitudinal fasciculus; SMD ϭ semantic dementia; UNC ϭ uncinate fasciculus.Diffusion tensor imaging (DTI) has recently emerged as a valuable technique for assessing structural changes in the brain.1-3 It can provide information on microstructural tissue integrity by measuring changes in water diffusion through tissue. This is particularly useful for assessing the integrity of white matter tracts because DTI can provide a measure ...

Objective: To identify the patterns of diffusivity changes in patients with dementia with Lewy bodies (DLB) and Alzheimer disease (AD) and to determine whether diffusion tensor MRI (DTI) is complementary to structural MRI in depicting the tissue abnormalities characteristic of DLB and AD. Methods:We studied clinically diagnosed age-, gender-, and education-matched subjects with DLB (n ϭ 30), subjects with AD (n ϭ 30), and cognitively normal (CN) subjects (n ϭ 60) in a case-control study. DTI was performed at 3T with a fluid-attenuated inversion recovery-based DTI sequence that enabled cortical diffusion measurements. Mean diffusivity (MD) and gray matter (GM) density were measured from segmented cortical regions. Tract-based diffusivity was measured using color-coded fractional anisotropy (FA) maps. Results:Patients with DLB were characterized by elevated MD in the amygdala and decreased FA in the inferior longitudinal fasciculus (ILF). ILF diffusivity was associated with the presence of visual hallucinations (p ϭ 0.007), and amygdala diffusivity was associated with Unified Parkinson's Disease Rating Scale (r ϭ 0.50; p ϭ 0.005) in DLB. In contrast, patients with AD were characterized by elevated MD in the medial temporal, temporal, and parietal lobe association cortices and decreased FA in the fornix, cingulum, and ILF. Amygdala diffusivity was complementary to GM density in discriminating DLB from CN; hippocampal and parahippocampal diffusivity was complementary to GM density in discriminating AD from CN. Conclusion:Increased amygdalar diffusivity in the absence of tissue loss in dementia with Lewy bodies (DLB) may be related to microvacuolation, a common pathology associated with Lewy body disease in the amygdala. Diffusivity measurements were complementary to structural MRI, demonstrating that measures of diffusivity on diffusion tensor MRI are valuable tools for characterizing the tissue abnormalities characteristic of Alzheimer disease and DLB. Neurology ® 2010;74:1814 -1821 GLOSSARY AD ϭ Alzheimer disease; CN ϭ cognitively normal; DLB ϭ dementia with Lewy bodies; DTI ϭ diffusion tensor MRI; FA ϭ fractional anisotropy; FDR ϭ false discovery rate; FLAIR ϭ fluid-attenuated inversion recovery; GM ϭ gray matter; ILF ϭ inferior longitudinal fasciculus; LB ϭ Lewy body; MD ϭ mean diffusivity; RBD ϭ REM sleep behavior disorder; ROI ϭ region of interest; SLF ϭ superior longitudinal fasciculus; TE ϭ echo time; TI ϭ inversion time; TR ϭ repetition time; UPDRS ϭ Unified Parkinson's Disease Rating Scale; WM ϭ white matter.Dementia with Lewy bodies (DLB) is the second most common cause of neurodegenerative dementia after Alzheimer disease (AD).1 Although patients with Lewy body (LB) pathology typically have some AD pathology, 2 noninvasive imaging markers that can distinguish the contribution of these different pathologies to the dementia syndrome may be useful for the differential diagnosis and may provide insight into the pathologic mechanisms underlying these disorders.Diffusion tensor MRI (DTI) provides infor...

Specific cognitive domain functions are associated with distinct patterns of cortical and white matter diffusivity in elderly with no dementia. Posterior cingulum tract FA was associated with all 4 cognitive domain functions, in agreement with the hypothesis that the posterior cingulate cortex is the main connectivity hub for cognitive brain networks. Microstructural changes identified on DTI may be associated with neurodegenerative pathologies underlying cognitive changes in older adults without dementia.

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Purpose To assess 12-month outcomes and safety of clinical magnetic resonance (MR)–guided focused ultrasound (US) treatments of uterine leiomyomas. Materials and Methods Between March 2005 and December 2009, 150 women with symptomatic uterine leiomyomas were clinically treated with MR-guided focused US at a single institution; 130 patients completed treatment and agreed to have their data used for research purposes. Patients were followed through retrospective review of medical records and phone interviews conducted at 3-, 6-, and 12-month intervals after treatment to assess additional procedures and symptom relief. Outcome measures and treatment complications were analyzed for possible correlations with the appearance of the tumors on T2-weighted imaging. Results The cumulative incidence of additional tumor-related treatments 12 months after MR-guided focused US was 7.4% by the Kaplan–Meier method. At 3-, 6-, and 12-month follow-up, 86% (90 of 105), 93% (92 of 99), and 88% (78 of 89) of patients reported relief of symptoms, respectively. No statistically significant correlation between tumor appearance on T2-weighted imaging and 12-month outcome was found. Treatment-related complications were observed in 17 patients (13.1%): 16 patients had minor complications and one had a major complication (deep vein thrombosis). All complications were resolved within the 12-month follow-up period. Conclusions MR-guided focused US is a noninvasive treatment option that can be used to effectively and safely treat uterine leiomyomas and delivers significant and lasting symptom relief for at least 12 months. The incidence of additional treatment during this time period is comparable with those in previous reports of uterine artery embolization.