Zobrazení tenzorů difuze (diffusion tensor imaging, DT I) je poměrně nová technika vyšetření magnetickou rezonancí, která je v současné době jako jediná schopna zobrazit bližší strukturální detaily bílé hmoty mozku. Sofistikované softwarové zpracování základních dat umožňuje vizualizovat jednotlivé dráhy nebo měřit číselné hodnoty parametrů DTI, které dle dosavadních publikací citlivě reagují na strukturální poškození bílé hmoty. Autoři této práce si kladou za cíl přinést přehled současných aplikací DT I pro zobrazení bílé hmoty mozku. Probírány jsou základní technické aspekty, možnosti praktického využití této metody v běžné klinické praxi a v neposlední řadě i ryze výzkumné aplikace směřující k detekci a kvantifikaci diskrétní ultrastrukturální patologie u různých onemocnění bílé hmoty mozkové.

Diffusion tensor imaging (DTI) is a relatively new magnetic resonance imaging technique that is capable of unique depiction of the structural detail in brain white matter. Its sophisticated software algorithms provide either three-dimensional reconstructions and visualizations of the particular tracts of the white matter or quantifications of various DTI parameters that appear, according to certain studies, to be highly sensitive to structural abnormalities in white matter. The aim of the present paper is to review the current applications of DTI for the depiction of brain white matter. Some basic technical remarks are made and clinical aspects are discussed, as well as purely research applications aimed at the detection and quantification of the subtle ultra-structural pathology of brain white matter.

• MeSH
• amyotrofická laterální skleróza diagnóza   MeSH
• centrální nervový systém fyziologie   patofyziologie   patologie   MeSH
• diagnostické techniky neurologické přístrojové vybavení   trendy   využití   MeSH
• difuzní magnetická rezonance metody   přístrojové vybavení   využití   MeSH
• financování organizované MeSH
• lidé MeSH
• nádory mozku diagnóza   etiologie   MeSH
• nemoci mozku diagnóza   etiologie   MeSH
• nervová tkáň MeSH
• nervové dráhy MeSH
• počítačové zpracování obrazu metody   přístrojové vybavení   využití   MeSH
• předoperační péče metody   využití   MeSH
• roztroušená skleróza diagnóza   MeSH
• schizofrenie diagnóza   MeSH
• stereotaktické techniky přístrojové vybavení   využití   MeSH
• zobrazování trojrozměrné metody   přístrojové vybavení   využití   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• přehledy MeSH

OBJECTIVE: The potential of magnetization transfer imaging (MTI) and diffusion tensor imaging (DTI) for the detection and evolution of new multiple sclerosis (MS) lesions was analyzed. METHODS: Nineteen patients with MS obtained conventional MRI, MTI, and DTI examinations bimonthly for 12 months and again after 24 months at 1.5 T MRI. MTI was acquired with balanced steady-state free precession (bSSFP) in 10 min (1.3 mm3 isotropic resolution) yielding both magnetization transfer ratio (MTR) and quantitative magnetization transfer (qMT) parameters (pool size ratio (F), exchange rate (kf), and relaxation times (T1/T2)). DTI provided fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD). RESULTS: At the time of their appearance on MRI, the 21 newly detected MS lesions showed significantly reduced MTR/F/kf and prolonged T1/T2 parameters, as well as significantly reduced FA and increased AD/MD/RD. Significant differences were already observed for MTR 4 months and for qMT parameters 2 months prior to lesions' detection on MRI. DTI did not show any significant pre-lesional differences. Slightly reversed trends were observed for most lesions up to 8 months after their detection for qMT and less pronounced for MTR and three diffusion parameters, while appearing unchanged on MRI. CONCLUSIONS: MTI provides more information than DTI in MS lesions and detects tissue changes 2 to 4 months prior to their appearance on MRI. After lesions' detection, qMT parameter changes promise to be more sensitive than MTR for the lesions' evolutional assessment. Overall, bSSFP-based MTI adumbrates to be more sensitive than MRI and DTI for the early detection and follow-up assessment of MS lesions. CLINICAL RELEVANCE STATEMENT: When additionally acquired in routine MRI, fast bSSFP-based MTI can complement the MRI/DTI longitudinal lesion assessment by detecting MS lesions 2-4 months earlier than with MRI, which could implicate earlier clinical decisions and better follow-up/treatment assessment in MS patients. KEY POINTS: • Magnetization transfer imaging provides more information than DTI in multiple sclerosis lesions and can detect tissue changes 2 to 4 months prior to their appearance on MRI. • After lesions' detection, quantitative magnetization transfer changes are more pronounced than magnetization transfer ratio changes and therefore promise to be more sensitive for the lesions' evolutional assessment. • Balanced steady-state free precession-based magnetization transfer imaging is more sensitive than MRI and DTI for the early detection and follow-up assessment of multiple sclerosis lesions.

• MeSH
• anizotropie MeSH
• lidé MeSH
• magnetická rezonanční tomografie metody   MeSH
• mozek diagnostické zobrazování   patologie   MeSH
• roztroušená skleróza * diagnostické zobrazování   patologie   MeSH
• zobrazování difuzních tenzorů * metody   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

Many patients with dementia with Lewy bodies (DLB) have overlapping Alzheimer's disease (AD)-related pathology, which may contribute to white matter (WM) diffusivity alterations on diffusion tensor imaging (DTI). Consecutive patients with DLB (n = 30), age- and sex-matched AD patients (n = 30), and cognitively normal controls (n = 60) were recruited. All subjects underwent DTI, 18F 2-fluoro-deoxy-d-glucose, and (11)C Pittsburgh compound B positron emission tomography scans. DLB patients had reduced fractional anisotropy (FA) in the parietooccipital WM but not elsewhere compared with cognitively normal controls, and elevated FA in parahippocampal WM compared with AD patients, which persisted after controlling for β-amyloid load in DLB. The pattern of WM FA alterations on DTI was consistent with the more diffuse posterior parietal and occipital glucose hypometabolism of 2-fluoro-deoxy-d-glucose positron emission tomography in the cortex. DLB is characterized by a loss of parietooccipital WM integrity, independent of concomitant AD-related β-amyloid load. Cortical glucose hypometabolism accompanies WM FA alterations with a concordant pattern of gray and WM involvement in the parietooccipital lobes in DLB.

• MeSH
• amyloidní beta-protein metabolismus   MeSH
• anizotropie MeSH
• bílá hmota patologie   MeSH
• demence s Lewyho tělísky metabolismus   patologie   MeSH
• glukosa metabolismus   MeSH
• lidé středního věku MeSH
• lidé MeSH
• pozitronová emisní tomografie MeSH
• senioři MeSH
• týlní lalok metabolismus   MeSH
• zobrazování difuzních tenzorů metody   MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH

BACKGROUND: Segmentation of the gray and white matter (GM, WM) of the human spinal cord in MRI images as well as the analysis of spinal cord diffusivity are challenging. When appropriately segmented, diffusion tensor imaging (DTI) of the spinal cord might be beneficial in the diagnosis and prognosis of several diseases. PURPOSE: To evaluate the applicability of a semiautomatic algorithm provided by ITK-SNAP in classification mode (CLASS) for segmenting cervical spinal cord GM, WM in MRI images and analyzing DTI parameters. STUDY TYPE: Prospective. SUBJECTS: Twenty healthy volunteers. SEQUENCES: 1.5T, turbo spin echo, fast field echo, single-shot echo planar imaging. ASSESSMENT: Three raters segmented the tissues by manual, CLASS, and atlas-based methods (Spinal Cord Toolbox, SCT) on T2 -weighted and DTI images. Masks were quantified by similarity and distance metrics, then analyzed for repeatability and mutual comparability. Masks created over T2 images were registered into diffusion space and fractional anisotropy (FA) values were statistically evaluated for dependency on method, rater, or tissue. STATISTICAL TESTS: t-test, analysis of variance (ANOVA), coefficient of variation, Dice coefficient, Hausdorff distance. RESULTS: CLASS segmentation reached better agreement with manual segmentation than did SCT (P < 0.001). Intra- and interobserver repeatability of SCT was better for GM and WM (both P < 0.001) but comparable with CLASS in entire spinal cord segmentation (P = 0.17 and P = 0.07, respectively). While FA values of whole spinal cord were not influenced by choice of segmentation method, both semiautomatic methods yielded lower FA values (P < 0.005) for GM than did the manual technique (mean differences 0.02 and 0.04 for SCT and CLASS, respectively). Repeatability of FA values for all methods was sufficient, with mostly less than 2% variance. DATA CONCLUSION: The presented semiautomatic method in combination with the proposed approach to data registration and analyses of spinal cord diffusivity can potentially be used as an alternative to atlas-based segmentation. LEVEL OF EVIDENCE: 1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;47:1217-1227.

• MeSH
• algoritmy MeSH
• anizotropie MeSH
• bílá hmota diagnostické zobrazování   MeSH
• difuzní magnetická rezonance * MeSH
• dospělí MeSH
• echoplanární zobrazování * MeSH
• krční mícha diagnostické zobrazování   MeSH
• lidé MeSH
• mladý dospělý MeSH
• odchylka pozorovatele MeSH
• počítačové zpracování obrazu metody   MeSH
• poranění míchy diagnostické zobrazování   MeSH
• prospektivní studie MeSH
• šedá hmota diagnostické zobrazování   MeSH
• strojové učení MeSH
• zobrazování difuzních tenzorů * MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

V krátkém sdělení dokumentujeme u pacienta s gliomem postihujícím precentrální gyrus relativitu výsledku zobrazení pyramidové dráhy pomocí DW traktografie a diskutujeme o faktorech, které mohou ovlivnit zobrazení dráhy. Dle našeho názoru se v dostupné literatuře nevěnuje dostatečná pozornost volbě oblasti zájmu trasování, přičemž právě ta je klíčovým determinantem výsledku.

In our short report, we show the relative nature of pyramidal tract representation using Diffusion Tensor Imaging in a patient with a precentral gyrus glioma and we discuss the factors that may affect tract reconstruction. We believe that, so far, inadequate attention has been paid in the published literature to the region of interest selection even though this is the key determinant of the imaging outcome. Key words: glioma – navigation – tractography – electric cortical stimulation The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manu­script met the ICMJE “uniform requirements” for biomedical papers.

• MeSH
• dospělí MeSH
• elektrická stimulace MeSH
• epilepsie parciální senzorická diagnóza   etiologie   MeSH
• gliom * diagnóza   chirurgie   MeSH
• magnetická rezonanční tomografie metody   využití   MeSH
• neurochirurgické výkony * metody   využití   MeSH
• perioperační období MeSH
• pooperační období MeSH
• pyramidové dráhy anatomie a histologie   patofyziologie   patologie   MeSH
• statistika jako téma MeSH
• stereotaktické techniky * využití   MeSH
• výsledky a postupy - zhodnocení (zdravotní péče) MeSH
• zobrazování difuzních tenzorů metody   využití   MeSH
• Check Tag
• dospělí MeSH
• mužské pohlaví MeSH
• Publikační typ
• kazuistiky MeSH
• práce podpořená grantem MeSH

Attention-deficit/hyperactivity disorder predominantly inattentive (ADHD-PI) and combined (ADHD-C) presentations are likely distinct disorders that differ neuroanatomically, neurochemically, and neuropsychologically. However, to date, little is known about specific white matter (WM) regions differentiating ADHD presentations. This study examined differences in WM microstructure using diffusion tensor imaging (DTI) data from 20 ADHD-PI, 18 ADHD-C, and 27 typically developed children. Voxel-wise analysis of DTI measurements in major fiber bundles was carried out using tract-based spatial statistics (TBSS). Clusters showing diffusivity abnormalities were used as regions of interest for regression analysis between fractional anisotropy (FA) and neuropsychological outcomes. Compared to neurotypicals, ADHD-PI children showed higher FA in the anterior thalamic radiations (ATR), bilateral inferior longitudinal fasciculus (ILF), and in the left corticospinal tract (CST). In contrast, the ADHD-C group exhibited higher FA in the bilateral cingulum bundle (CB). In the ADHD-PI group, differences in FA in the left ILF and ATR were accompanied by axial diffusivity (AD) abnormalities. In addition, the ADHD-PI group exhibited atypical mean diffusivity in the forceps minor (FMi) and left ATR and AD differences in right CB compared to healthy subjects. Direct comparison between ADHD presentations demonstrated radial diffusivity differences in FMi. WM clusters with FA irregularities in ADHD were associated with neurobehavioral performance across groups. In conclusion, differences in WM microstructure in ADHD presentations strengthen the theory that ADHD-PI and ADHD-C are two distinct disorders. Regions with WM irregularity seen in both ADHD presentations might serve as predictors of executive and behavioral functioning across groups. Hum Brain Mapp 37:3323-3336, 2016. © 2016 Wiley Periodicals, Inc.

• MeSH
• bílá hmota patologie   MeSH
• dítě MeSH
• hyperkinetická porucha patologie   MeSH
• interpretace obrazu počítačem MeSH
• lidé MeSH
• mapování mozku MeSH
• mozek patologie   MeSH
• nervové dráhy patologie   MeSH
• neuropsychologické testy MeSH
• zobrazování difuzních tenzorů MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH

A wide range of imaging studies provides growing support for the potential role of diffusion tensor imaging (DTI) in evaluating microstructural white matter integrity in Alzheimer disease (AD) and mild cognitive impairment (MCI). Our review aims to present DTI principles, post-processing and analysis frameworks and to report the results of particular studies. The distribution of AD-related white matter abnormalities is widely discussed in the light of deteriorated connectivity within certain tracts due to secondary white matter degeneration; primary alterations are also assumed to contribute to the pattern. The question whether it is more effective to assess the whole-brain diffusion or to directly concentrate on specific regions remains an interesting issue. Assessing white matter microstructure alterations, as evaluated by group-level differences of tensor-derived parameters, may be a promising neuroimaging tool for differential diagnosis between AD, MCI and other cognitive disorders, as well as being particularly helpful in the interpretation of underlying pathological processes.

• MeSH
• Alzheimerova nemoc komplikace   diagnóza   patologie   MeSH
• diferenciální diagnóza MeSH
• kognitivní dysfunkce etiologie   MeSH
• kognitivní poruchy diagnóza   MeSH
• leukoencefalopatie diagnóza   MeSH
• lidé MeSH
• mozek patologie   MeSH
• zobrazování difuzních tenzorů * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

The aim of this study was to investigate whether white matter changes as measured by diffusion tensor imaging (DTI) can help differentiate shunt-responsive idiopathic normal pressure hydrocephalus (iNPH) patients from patients with other causes of gait disturbances and/or cognitive decline with ventriculomegaly whose clinical symptoms do not improve significantly after cerebrospinal fluid derivation (non-iNPH). Between 2017 and 2022, 85 patients with probable iNPH underwent prospective preoperative magnetic resonance imaging (MRI) and comprehensive clinical workup. Patients with clinical symptoms of iNPH, positive result on lumbar infusion test, and gait improvement after 120-h lumbar drainage were diagnosed with iNPH and underwent shunt-placement surgery. Fractional anisotropy (FA) and mean diffusivity (MD) values for individual regions of interest were extracted from preoperative MRI, using the TBSS pipeline of FSL toolkit. These FA and MD values were then compared to results of clinical workup and established diagnosis of iNPH. An identical MRI protocol was performed on 13 age- and sex-matched healthy volunteers. Statistically significant differences in FA values of several white matter structures were found not only between iNPH patients and healthy controls but also between iNPH and non-iNPH patients. ROI that showed best diagnostic ability when differentiating iNPH among probable iNPH cohort was uncinate fasciculus, with AUC of 0.74 (p < 0.001). DTI methods of white matter analysis using standardised methods of ROI extraction can help in differentiation of iNPH patients not only from healthy patients but also from patients with other causes of gait disturbances with cognitive decline and ventriculomegaly.

• MeSH
• difuzní magnetická rezonance metody   MeSH
• lidé MeSH
• magnetická rezonanční tomografie MeSH
• normotenzní hydrocefalus * diagnostické zobrazování   chirurgie   MeSH
• prospektivní studie MeSH
• zobrazování difuzních tenzorů metody   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

To meet the need for Parkinson's disease biomarkers and evidence for amount and distribution of pathological changes, MRI diffusion tensor imaging (DTI) has been explored in a number of previous studies. However, conflicting results warrant further investigations. As tissue microstructure, particularly of the grey matter, is heterogeneous, a more precise diffusion model may benefit tissue characterization. The purpose of this study was to analyze the diffusion-based imaging technique restriction spectrum imaging (RSI) and DTI, and their ability to detect microstructural changes within brain regions associated with motor function in Parkinson's disease. Diffusion weighted (DW) MR images of a total of 100 individuals, (46 Parkinson's disease patients and 54 healthy controls) were collected using b-values of 0-4000s/mm2. Output diffusion-based maps were estimated based on the RSI-model combining the full set of DW-images (Cellular Index (CI), Neurite Density (ND)) and DTI-model combining b = 0 and b = 1000 s/mm2 (fractional anisotropy (FA), Axial-, Mean- and Radial diffusivity (AD, MD, RD)). All parametric maps were analyzed in a voxel-wise group analysis, with focus on typical brain regions associated with Parkinson's disease pathology. CI, ND and DTI diffusivity metrics (AD, MD, RD) demonstrated the ability to differentiate between groups, with strongest performance within the thalamus, prone to pathology in Parkinson's disease. Our results indicate that RSI may improve the predictive power of diffusion-based MRI, and provide additional information when combined with the standard diffusivity measurements. In the absence of major atrophy, diffusion techniques may reveal microstructural pathology. Our results suggest that protocols for MRI diffusion imaging may be adapted to more sensitive detection of pathology at different sites of the central nervous system.

• MeSH
• degenerace nervu diagnóza   diagnostické zobrazování   patologie   MeSH
• diagnostické zobrazování * MeSH
• difuzní magnetická rezonance MeSH
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mozkový kmen diagnostické zobrazování   patologie   MeSH
• Parkinsonova nemoc diagnóza   diagnostické zobrazování   patologie   MeSH
• šedá hmota diagnostické zobrazování   patologie   MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• substantia nigra diagnostické zobrazování   patologie   MeSH
• thalamus diagnostické zobrazování   patologie   MeSH
• zobrazování difuzních tenzorů * MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

INTRODUCTION: The paper focuses on the use of diffusion tensor imaging (DTI) in the evaluation of one case of Chiari III malformation. CASE REPORT: In the case discussed, DTI was used to delineate the position of large descending tracts within the malformation and the reconstructed images were used to plan the surgical procedure. DISCUSSION: The clinical and imaging findings, the technical aspects of the DTI fiber tract reconstruction and the outcome are summarized.

• MeSH
• Arnoldův-Chiariho syndrom patologie   chirurgie   MeSH
• difuzní magnetická rezonance MeSH
• encefalokéla patologie   chirurgie   MeSH
• fatální výsledek MeSH
• lidé MeSH
• nervová tkáň patologie   chirurgie   MeSH
• neurochirurgické výkony MeSH
• novorozenec MeSH
• počítačové zpracování obrazu MeSH
• pyramidové dráhy abnormality   patologie   chirurgie   MeSH
• ventrikuloperitoneální zkrat MeSH
• Check Tag
• lidé MeSH
• novorozenec MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• kazuistiky MeSH
• práce podpořená grantem MeSH