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1.
Neurobiol Aging ; 84: 9-16, 2019 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-31491596

RESUMO

Brain imaging data are increasingly made publicly accessible, and volumetric imaging measures derived from population-based cohorts may serve as normative data for individual patient diagnostic assessment. Yet, these normative cohorts are usually not a perfect reflection of a patient's base population, nor are imaging parameters such as field strength or scanner type similar. In this proof of principle study, we assessed differences between reference curves of subcortical structure volumes of normal controls derived from two population-based studies and a case-control study. We assessed the impact of any differences on individual assessment of brain structure volumes. Percentile curves were fitted on the three healthy cohorts. Next, percentile values for these subcortical structures for individual patients from these three cohorts, 91 mild cognitive impairment and 95 Alzheimer's disease cases and patients from the Alzheimer Center, were calculated, based on the distributions of each of the three cohorts. Overall, we found that the subcortical volume normative data from these cohorts are highly interchangeable, suggesting more flexibility in clinical implementation.

2.
J Neurol Neurosurg Psychiatry ; 90(9): 997-1004, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31123142

RESUMO

BACKGROUND: Semantic dementia (SD) is a neurodegenerative disorder characterised by progressive language problems falling within the clinicopathological spectrum of frontotemporal lobar degeneration (FTLD). The development of disease-modifying agents may be facilitated by the relative clinical and pathological homogeneity of SD, but we need robust monitoring biomarkers to measure their efficacy. In different FTLD subtypes, neurofilament light chain (NfL) is a promising marker, therefore we investigated the utility of cerebrospinal fluid (CSF) NfL in SD. METHODS: This large retrospective multicentre study compared cross-sectional CSF NfL levels of 162 patients with SD with 65 controls. CSF NfL levels of patients were correlated with clinical parameters (including survival), neuropsychological test scores and regional grey matter atrophy (including longitudinal data in a subset). RESULTS: CSF NfL levels were significantly higher in patients with SD (median: 2326 pg/mL, IQR: 1628-3593) than in controls (577 (446-766), p<0.001). Higher CSF NfL levels were moderately associated with naming impairment as measured by the Boston Naming Test (rs =-0.32, p=0.002) and with smaller grey matter volume of the parahippocampal gyri (rs =-0.31, p=0.004). However, cross-sectional CSF NfL levels were not associated with progression of grey matter atrophy and did not predict survival. CONCLUSION: CSF NfL is a promising biomarker in the diagnostic process of SD, although it has limited cross-sectional monitoring or prognostic abilities.

3.
MAGMA ; 2018 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-29916058

RESUMO

OBJECTIVE: Partial volume (PV) correction is an important step in arterial spin labeling (ASL) MRI that is used to separate perfusion from structural effects when computing the mean gray matter (GM) perfusion. There are three main methods for performing this correction: (1) GM-threshold, which includes only voxels with GM volume above a preset threshold; (2) GM-weighted, which uses voxel-wise GM contribution combined with thresholding; and (3) PVC, which applies a spatial linear regression algorithm to estimate the flow contribution of each tissue at a given voxel. In all cases, GM volume is obtained using PV maps extracted from the segmentation of the T1-weighted (T1w) image. As such, PV maps contain errors due to the difference in readout type and spatial resolution between ASL and T1w images. Here, we estimated these errors and evaluated their effect on the performance of each PV correction method in computing GM cerebral blood flow (CBF). MATERIALS AND METHODS: Twenty-two volunteers underwent scanning using 2D echo planar imaging (EPI) and 3D spiral ASL. For each PV correction method, GM CBF was computed using PV maps simulated to contain estimated errors due to spatial resolution mismatch and geometric distortions which are caused by the mismatch in readout between ASL and T1w images. Results were analyzed to assess the effect of each error on the estimation of GM CBF from ASL data. RESULTS: Geometric distortion had the largest effect on the 2D EPI data, whereas the 3D spiral was most affected by the resolution mismatch. The PVC method outperformed the GM-threshold even in the presence of combined errors from resolution mismatch and geometric distortions. The quantitative advantage of PVC was 16% without and 10% with the combined errors for both 2D and 3D ASL. Consistent with theoretical expectations, for error-free PV maps, the PVC method extracted the true GM CBF. In contrast, GM-weighted overestimated GM CBF by 5%, while GM-threshold underestimated it by 16%. The presence of PV map errors decreased the calculated GM CBF for all methods. CONCLUSION: The quality of PV maps presents no argument for the preferential use of the GM-threshold method over PVC in the clinical application of ASL.

4.
J Alzheimers Dis ; 56(2): 789-804, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28059782

RESUMO

Semantic dementia (SD) and behavioral variant frontotemporal dementia (bvFTD), subtypes of frontotemporal dementia, are characterized by distinct clinical symptoms and neuroimaging features, with predominant left temporal grey matter (GM) atrophy in SD and bilateral or right frontal GM atrophy in bvFTD. Such differential hemispheric predilection may also be reflected by other neuroimaging features, such as brain connectivity. This study investigated white matter (WM) microstructure and functional connectivity differences between SD and bvFTD, focusing on the hemispheric predilection of these differences. Eight SD and 12 bvFTD patients, and 17 controls underwent diffusion tensor imaging and resting state functional MRI at 3T. Whole-brain WM microstructure was assessed to determine distinct WM tracts affected in SD and bvFTD. For these tracts, diffusivity measures and lateralization indices were calculated. Functional connectivity was established for GM regions affected in early stage SD or bvFTD. Results of a direct comparison between SD and bvFTD are reported. Whole-brain WM microstructure abnormalities were more pronounced in the left hemisphere in SD and bilaterally- with a slight predilection for the right- in bvFTD. Lateralization of tract-specific abnormalities was seen in SD only, toward the left hemisphere. Functional connectivity of disease-specific regions was mainly decreased bilaterally in SD and in the right hemisphere in bvFTD. SD and bvFTD show WM microstructure and functional connectivity abnormalities in different regions, that are respectively more pronounced in the left hemisphere in SD and in the right hemisphere in bvFTD. This indicates differential hemispheric predilection of brain connectivity abnormalities between SD and bvFTD.


Assuntos
Encéfalo/diagnóstico por imagem , Encéfalo/fisiopatologia , Demência Frontotemporal/diagnóstico por imagem , Demência Frontotemporal/fisiopatologia , Substância Branca/diagnóstico por imagem , Substância Branca/fisiopatologia , Mapeamento Encefálico , Imagem de Tensor de Difusão , Feminino , Lateralidade Funcional , Substância Cinzenta/diagnóstico por imagem , Substância Cinzenta/fisiopatologia , Humanos , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Vias Neurais/diagnóstico por imagem , Vias Neurais/fisiopatologia , Tamanho do Órgão , Descanso
5.
Eur Radiol ; 27(8): 3372-3382, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27986990

RESUMO

OBJECTIVES: To investigate the added diagnostic value of arterial spin labelling (ASL) and diffusion tensor imaging (DTI) to structural MRI for computer-aided classification of Alzheimer's disease (AD), frontotemporal dementia (FTD), and controls. METHODS: This retrospective study used MRI data from 24 early-onset AD and 33 early-onset FTD patients and 34 controls (CN). Classification was based on voxel-wise feature maps derived from structural MRI, ASL, and DTI. Support vector machines (SVMs) were trained to classify AD versus CN (AD-CN), FTD-CN, AD-FTD, and AD-FTD-CN (multi-class). Classification performance was assessed by the area under the receiver-operating-characteristic curve (AUC) and accuracy. Using SVM significance maps, we analysed contributions of brain regions. RESULTS: Combining ASL and DTI with structural MRI resulted in higher classification performance for differential diagnosis of AD and FTD (AUC = 84%; p = 0.05) than using structural MRI by itself (AUC = 72%). The performance of ASL and DTI themselves did not improve over structural MRI. The classifications were driven by different brain regions for ASL and DTI than for structural MRI, suggesting complementary information. CONCLUSIONS: ASL and DTI are promising additions to structural MRI for classification of early-onset AD, early-onset FTD, and controls, and may improve the computer-aided differential diagnosis on a single-subject level. KEY POINTS: • Multiparametric MRI is promising for computer-aided diagnosis of early-onset AD and FTD. • Diagnosis is driven by different brain regions when using different MRI methods. • Combining structural MRI, ASL, and DTI may improve differential diagnosis of dementia.


Assuntos
Doença de Alzheimer/diagnóstico por imagem , Demência Frontotemporal/diagnóstico por imagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Encéfalo/diagnóstico por imagem , Diagnóstico por Computador/métodos , Diagnóstico Diferencial , Imagem de Tensor de Difusão/métodos , Diagnóstico Precoce , Feminino , Humanos , Imagem por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Curva ROC , Estudos Retrospectivos , Marcadores de Spin , Máquina de Vetores de Suporte
6.
Neurobiol Aging ; 43: 119-28, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27255821

RESUMO

This study investigates regional coherence between white matter (WM) microstructure and gray matter (GM) volume and perfusion measures in Alzheimer's disease (AD) and behavioral variant frontotemporal dementia (bvFTD) using a correlational approach. WM-GM coherence, compared with controls, was stronger between cingulum WM and frontotemporal GM in AD, and temporoparietal GM in bvFTD. In addition, in AD compared with controls, coherence was stronger between inferior fronto-occipital fasciculus WM microstructure and occipital GM perfusion. In this first study assessing regional WM-GM coherence in AD and bvFTD, we show that WM microstructure and GM volume and perfusion measures are coherent, particularly in regions implicated in AD and bvFTD pathology. This indicates concurrent degeneration in disease-specific networks. Our methodology allows for the detection of incipient abnormalities that go undetected in conventional between-group analyses.


Assuntos
Doença de Alzheimer/diagnóstico por imagem , Doença de Alzheimer/patologia , Demência Frontotemporal/diagnóstico por imagem , Demência Frontotemporal/patologia , Substância Cinzenta/diagnóstico por imagem , Substância Cinzenta/patologia , Degeneração Neural/diagnóstico por imagem , Degeneração Neural/patologia , Substância Branca/diagnóstico por imagem , Substância Branca/patologia , Idoso , Imagem de Difusão por Ressonância Magnética , Feminino , Humanos , Angiografia por Ressonância Magnética , Masculino , Pessoa de Meia-Idade
7.
Neuroimage Clin ; 11: 595-605, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27222795

RESUMO

PURPOSE: 'Phenocopy' frontotemporal dementia (phFTD) patients may clinically mimic the behavioral variant of FTD (bvFTD), but do not show functional decline or abnormalities upon visual inspection of routine neuroimaging. We aimed to identify abnormalities in gray matter (GM) volume and perfusion in phFTD and to assess whether phFTD belongs to the FTD spectrum. We compared phFTD patients with both healthy controls and bvFTD patients. MATERIALS & METHODS: Seven phFTD and 11 bvFTD patients, and 20 age-matched controls underwent structural T1-weighted magnetic resonance imaging (MRI) and 3D pseudo-continuous arterial spin labeling (pCASL) at 3T. Normalized GM (nGM) volumes and perfusion, corrected for partial volume effects, were quantified regionally as well as in the entire supratentorial cortex, and compared between groups taking into account potential confounding effects of gender and scanner. RESULTS: PhFTD patients showed cortical atrophy, most prominently in the right temporal lobe. Apart from this regional atrophy, GM volume was generally not different from either controls or from bvFTD. BvFTD however showed extensive frontotemporal atrophy. Perfusion was increased in the left prefrontal cortex compared to bvFTD and to a lesser extent to controls. CONCLUSION: PhFTD and bvFTD show overlapping cortical structural abnormalities indicating a continuum of changes especially in the frontotemporal regions. Together with functional changes suggestive of a compensatory response to incipient pathology in the left prefrontal regions, these findings are the first to support a possible neuropathological etiology of phFTD and suggest that phFTD may be a neurodegenerative disease on the FTD spectrum.


Assuntos
Mapeamento Encefálico , Encéfalo/diagnóstico por imagem , Encéfalo/fisiopatologia , Circulação Cerebrovascular/fisiologia , Demência Frontotemporal/patologia , Idoso , Estudos de Casos e Controles , Feminino , Seguimentos , Demência Frontotemporal/diagnóstico por imagem , Substância Cinzenta/diagnóstico por imagem , Substância Cinzenta/patologia , Humanos , Imagem Tridimensional , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Escalas de Graduação Psiquiátrica , Marcadores de Spin
8.
Eur Radiol ; 26(1): 244-53, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26024845

RESUMO

OBJECTIVE: To investigate arterial spin labeling (ASL)-MRI for the early diagnosis of and differentiation between the two most common types of presenile dementia: Alzheimer's disease (AD) and frontotemporal dementia (FTD), and for distinguishing age-related from pathological perfusion changes. METHODS: Thirteen AD and 19 FTD patients, and 25 age-matched older and 22 younger controls underwent 3D pseudo-continuous ASL-MRI at 3 T. Gray matter (GM) volume and cerebral blood flow (CBF), corrected for partial volume effects, were quantified in the entire supratentorial cortex and in 10 GM regions. Sensitivity, specificity and diagnostic performance were evaluated in regions showing significant CBF differences between patient groups or between patients and older controls. RESULTS: AD compared with FTD patients had hypoperfusion in the posterior cingulate cortex, differentiating these with a diagnostic performance of 74 %. Compared to older controls, FTD patients showed hypoperfusion in the anterior cingulate cortex, whereas AD patients showed a more widespread regional hypoperfusion as well as atrophy. Regional atrophy was not different between AD and FTD. Diagnostic performance of ASL to differentiate AD or FTD from controls was good (78-85 %). Older controls showed global hypoperfusion compared to young controls. CONCLUSION: ASL-MRI contributes to early diagnosis of and differentiation between presenile AD and FTD. KEY POINTS: ASL-MRI facilitates differentiation of early Alzheimer's disease and frontotemporal dementia. Posterior cingulate perfusion is lower in Alzheimer's disease than frontotemporal dementia. Compared to controls, Alzheimer's disease patients show hypoperfusion in multiple regions. Compared to controls, frontotemporal dementia patients show focal anterior cingulate hypoperfusion. Global decreased perfusion in older adults differs from hypoperfusion in dementia.


Assuntos
Doença de Alzheimer/diagnóstico , Córtex Cerebral/patologia , Imagem Ecoplanar/métodos , Demência Frontotemporal/diagnóstico , Substância Cinzenta/patologia , Imagem Tridimensional/métodos , Adolescente , Adulto , Idoso , Atrofia/patologia , Circulação Cerebrovascular , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Tempo , Adulto Jovem
9.
PLoS One ; 10(7): e0132929, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26172381

RESUMO

Arterial spin labeling (ASL) magnetic resonance imaging is increasingly used to quantify task-related brain activation. This study assessed functional ASL (fASL) using pseudo-continuous ASL (pCASL) product sequences from two vendors. By scanning healthy participants twice with each sequence while they performed a motor task, this study assessed functional ASL for 1) its sensitivity to detect task-related cerebral blood flow (CBF) changes, and 2) its reproducibility of resting CBF and absolute CBF changes (delta CBF) in the motor cortex. Whole-brain voxel-wise analyses showed that sensitivity for motor activation was sufficient with each sequence, and comparable between sequences. Reproducibility was assessed with within-subject coefficients of variation (wsCV) and intraclass correlation coefficients (ICC). Reproducibility of resting CBF was reasonably good within (wsCV: 14.1-15.7%; ICC: 0.69-0.77) and between sequences (wsCV: 15.1%; ICC: 0.69). Reproducibility of delta CBF was relatively low, both within (wsCV: 182-297%; ICC: 0.04-0.32) and between sequences (wsCV: 185%; ICC: 0.45), while inter-session variation was low. This may be due to delta CBF's small mean effect (0.77-1.32 mL/100g gray matter/min). In conclusion, fASL seems sufficiently sensitive to detect task-related changes on a group level, with acceptable inter-sequence differences. Resting CBF may provide a consistent baseline to compare task-related activation to, but absolute regional CBF changes are more variable, and should be interpreted cautiously when acquired with two pCASL product sequences.


Assuntos
Artérias/fisiologia , Circulação Cerebrovascular/fisiologia , Adulto , Feminino , Substância Cinzenta/fisiologia , Voluntários Saudáveis , Humanos , Processamento de Imagem Assistida por Computador/métodos , Angiografia por Ressonância Magnética/métodos , Masculino , Atividade Motora/fisiologia , Reprodutibilidade dos Testes , Descanso/fisiologia , Sensibilidade e Especificidade , Marcadores de Spin , Adulto Jovem
10.
Neuroimage ; 111: 562-79, 2015 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-25652394

RESUMO

Algorithms for computer-aided diagnosis of dementia based on structural MRI have demonstrated high performance in the literature, but are difficult to compare as different data sets and methodology were used for evaluation. In addition, it is unclear how the algorithms would perform on previously unseen data, and thus, how they would perform in clinical practice when there is no real opportunity to adapt the algorithm to the data at hand. To address these comparability, generalizability and clinical applicability issues, we organized a grand challenge that aimed to objectively compare algorithms based on a clinically representative multi-center data set. Using clinical practice as the starting point, the goal was to reproduce the clinical diagnosis. Therefore, we evaluated algorithms for multi-class classification of three diagnostic groups: patients with probable Alzheimer's disease, patients with mild cognitive impairment and healthy controls. The diagnosis based on clinical criteria was used as reference standard, as it was the best available reference despite its known limitations. For evaluation, a previously unseen test set was used consisting of 354 T1-weighted MRI scans with the diagnoses blinded. Fifteen research teams participated with a total of 29 algorithms. The algorithms were trained on a small training set (n=30) and optionally on data from other sources (e.g., the Alzheimer's Disease Neuroimaging Initiative, the Australian Imaging Biomarkers and Lifestyle flagship study of aging). The best performing algorithm yielded an accuracy of 63.0% and an area under the receiver-operating-characteristic curve (AUC) of 78.8%. In general, the best performances were achieved using feature extraction based on voxel-based morphometry or a combination of features that included volume, cortical thickness, shape and intensity. The challenge is open for new submissions via the web-based framework: http://caddementia.grand-challenge.org.


Assuntos
Algoritmos , Doença de Alzheimer/diagnóstico , Disfunção Cognitiva/diagnóstico , Diagnóstico por Computador/métodos , Interpretação de Imagem Assistida por Computador/métodos , Imagem por Ressonância Magnética/métodos , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/classificação , Disfunção Cognitiva/classificação , Diagnóstico por Computador/normas , Feminino , Humanos , Interpretação de Imagem Assistida por Computador/normas , Imagem por Ressonância Magnética/normas , Masculino , Pessoa de Meia-Idade , Sensibilidade e Especificidade
11.
MAGMA ; 28(5): 427-36, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25588906

RESUMO

OBJECT: The current study assesses the multicenter feasibility of pharmacological arterial spin labeling (ASL) by comparing a caffeine-induced relative cerebral blood flow decrease (%CBF↓) measured with two pseudo-continuous ASL sequences as provided by two major vendors. MATERIALS AND METHODS: Twenty-two healthy volunteers were scanned twice with both a 3D spiral (GE) and a 2D EPI (Philips) sequence. The inter-session reproducibility was evaluated by comparisons of the mean and within-subject coefficient of variability (wsCV) of the %CBF↓, both for the total cerebral gray matter and on a voxel level. RESULTS: The %CBF↓ was larger when measured with the 3D spiral sequence (23.9 ± 5.9 %) than when measured with the 2D EPI sequence (19.2 ± 5.6 %) on a total gray matter level (p = 0.02), and on a voxel level in the posterior watershed area (p < 0.001). There was no difference between the gray matter wsCV of the 3D spiral (57.3 %) and 2D EPI sequence (66.7 %, p = 0.3), whereas on a voxel level, the wsCV was visibly different between the sequences. CONCLUSION: The observed differences between ASL sequences of both vendors can be explained by differences in the employed readout modules. These differences may seriously hamper multicenter pharmacological ASL, which strongly encourages standardization of ASL implementations.


Assuntos
Encéfalo/fisiologia , Cafeína/administração & dosagem , Circulação Cerebrovascular/fisiologia , Imagem Tridimensional/instrumentação , Imagem Tridimensional/métodos , Angiografia por Ressonância Magnética/instrumentação , Encéfalo/efeitos dos fármacos , Circulação Cerebrovascular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Avaliação de Medicamentos/métodos , Desenho de Equipamento , Análise de Falha de Equipamento , Feminino , Humanos , Angiografia por Ressonância Magnética/métodos , Masculino , Estudos Multicêntricos como Assunto/métodos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Marcadores de Spin
12.
PLoS One ; 9(8): e104108, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25090654

RESUMO

PURPOSE: Prior to the implementation of arterial spin labeling (ASL) in clinical multi-center studies, it is important to establish its status quo inter-vendor reproducibility. This study evaluates and compares the intra- and inter-vendor reproducibility of pseudo-continuous ASL (pCASL) as clinically implemented by GE and Philips. MATERIAL AND METHODS: 22 healthy volunteers were scanned twice on both a 3T GE and a 3T Philips scanner. The main difference in implementation between the vendors was the readout module: spiral 3D fast spin echo vs. 2D gradient-echo echo-planar imaging respectively. Mean and variation of cerebral blood flow (CBF) were compared for the total gray matter (GM) and white matter (WM), and on a voxel-level. RESULTS: Whereas the mean GM CBF of both vendors was almost equal (p = 1.0), the mean WM CBF was significantly different (p<0.01). The inter-vendor GM variation did not differ from the intra-vendor GM variation (p = 0.3 and p = 0.5 for GE and Philips respectively). Spatial inter-vendor CBF and variation differences were observed in several GM regions and in the WM. CONCLUSION: These results show that total GM CBF-values can be exchanged between vendors. For the inter-vendor comparison of GM regions or WM, these results encourage further standardization of ASL implementation among vendors.


Assuntos
Angiografia , Imagem Ecoplanar/instrumentação , Neuroimagem/instrumentação , Reprodutibilidade dos Testes , Adulto , Artérias/fisiologia , Sistema Nervoso Central/fisiologia , Circulação Cerebrovascular/fisiologia , Comércio , Feminino , Voluntários Saudáveis , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Marcadores de Spin
13.
Hum Brain Mapp ; 35(9): 4916-31, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24700485

RESUMO

Because hypoperfusion of brain tissue precedes atrophy in dementia, the detection of dementia may be advanced by the use of perfusion information. Such information can be obtained noninvasively with arterial spin labeling (ASL), a relatively new MR technique quantifying cerebral blood flow (CBF). Using ASL and structural MRI, we evaluated diagnostic classification in 32 prospectively included presenile early stage dementia patients and 32 healthy controls. Patients were suspected of Alzheimer's disease (AD) or frontotemporal dementia. Classification was based on CBF as perfusion marker, gray matter (GM) volume as atrophy marker, and their combination. These markers were each examined using six feature extraction methods: a voxel-wise method and a region of interest (ROI)-wise approach using five ROI-sets in the GM. These ROI-sets ranged in number from 72 brain regions to a single ROI for the entire supratentorial brain. Classification was performed with a linear support vector machine classifier. For validation of the classification method on the basis of GM features, a reference dataset from the AD Neuroimaging Initiative database was used consisting of AD patients and healthy controls. In our early stage dementia population, the voxelwise feature-extraction approach achieved more accurate results (area under the curve (AUC) range = 86 - 91%) than all other approaches (AUC = 57 - 84%). Used in isolation, CBF quantified with ASL was a good diagnostic marker for dementia. However, our findings indicated only little added diagnostic value when combining ASL with the structural MRI data (AUC = 91%), which did not significantly improve over accuracy of structural MRI atrophy marker by itself.


Assuntos
Doença de Alzheimer/diagnóstico , Encéfalo/patologia , Encéfalo/fisiopatologia , Circulação Cerebrovascular , Interpretação de Imagem Assistida por Computador/métodos , Imagem por Ressonância Magnética/métodos , Idoso , Doença de Alzheimer/patologia , Doença de Alzheimer/fisiopatologia , Área Sob a Curva , Atrofia , Diagnóstico Diferencial , Feminino , Demência Frontotemporal/diagnóstico , Demência Frontotemporal/patologia , Demência Frontotemporal/fisiopatologia , Substância Cinzenta/patologia , Humanos , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Tamanho do Órgão , Estudos Prospectivos , Máquina de Vetores de Suporte
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