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1.
PLoS One ; 14(3): e0213905, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30883579

RESUMO

PURPOSE: Perfusion and diffusion magnetic resonance imaging (MRI) provide important biomarkers for brain tumor analysis. Our aim was to investigate if regions of increased perfusion or tumor with restricted diffusion on the immediate post-operative MRI examination would be predictive of time to tumor progression in patients with high-grade gliomas. MATERIALS AND METHODS: Twenty-three patients with high-grade gliomas were retrospectively analyzed. We measured the perfusion at the resection area and evaluated the presence or absence of the restricted diffusion in residual tumor masses. The associations of the perfusion, diffusion and contrast enhancement (delayed static enhancement (DSE)) characteristics with time to tumor progression were statistically calculated. We also evaluated if the location of the tumor progression was concordant to the areas of the elevated perfusion, tumor type restricted diffusion and enhancement. RESULTS: Patients with >200 days to progression are more likely to have no elevated relative cerebral blood volume (rCBV) ratio (p = 0.0004), no tumor restriction (p = 0.024), and no DSE (p = 0.052). The elevated mean rCBV ratio (p<0.001) and tumor type restricted diffusion (p = 0.002) were significantly associated with a higher risk of progression. All cases with rCBV ratio of >1.5 progressed in 275 days or earlier. Tumors tended to progress at the area where patients with post-operative MRIs showed elevated perfusion (p = 0.006), tumor-type restricted diffusion (p = 0.005) and DSE (p = 0.008). CONCLUSIONS: Post-operative analysis of rCBV, tumor type restricted diffusion and enhancement characteristics are predictive of time to progression, risk of progression and where tumor progression is likely to occur.


Assuntos
Neoplasias Encefálicas/diagnóstico por imagem , Glioma/diagnóstico por imagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/cirurgia , Volume Sanguíneo Cerebral , Imagem de Difusão por Ressonância Magnética , Progressão da Doença , Feminino , Glioma/patologia , Glioma/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade , Período Pós-Operatório , Estudos Retrospectivos
2.
Magn Reson Imaging ; 32(7): 796-803, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24856625

RESUMO

Quantification of the living human visual system using MRI methods has been challenging, but several applications demand a reliable and time-efficient data acquisition protocol. In this study, we demonstrate the utility of high-spatial-resolution diffusion tensor fiber tractography (DTT) in reconstructing and quantifying the human visual pathways. Five healthy males, age range 24-37years, were studied after approval of the institutional review board (IRB) at The University of Texas Health Science Center at Houston. We acquired diffusion tensor imaging (DTI) data with 1-mm slice thickness on a 3.0-Tesla clinical MRI scanner and analyzed the data using DTT with the fiber assignment by continuous tractography (FACT) algorithm. By utilizing the high-spatial-resolution DTI protocol with FACT algorithm, we were able to reconstruct and quantify bilateral optic pathways including the optic chiasm, optic tract, optic radiations free of contamination from neighboring white matter tracts.


Assuntos
Imagem de Tensor de Difusão/métodos , Aumento da Imagem/métodos , Nervo Óptico/anatomia & histologia , Trato Óptico/anatomia & histologia , Córtex Visual/anatomia & histologia , Vias Visuais/anatomia & histologia , Substância Branca/ultraestrutura , Adulto , Humanos , Masculino , Reconhecimento Automatizado de Padrão/métodos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Adulto Jovem
3.
Dev Med Child Neurol ; 53(4): 361-7, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21121904

RESUMO

AIM: Angelman syndrome is a neurogenetic disorder characterized by severe intellectual disability, absent speech, seizures, and outbursts of laughter. The aim of this study was to utilize diffusion tensor imaging (DTI) to examine alterations in white matter pathways in Angelman syndrome, with an emphasis on correlations with clinical severity. METHOD: DTI was used to examine the arcuate fasciculus (AF), uncinate fasciculus (UF), inferior longitudinal fasciculus (ILF), inferior fronto-occipital fasciculus (IFOF), and the corpus callosum (CC). We enrolled 14 children aged 8 to 17 years (mean age 10y 8mo; SD 2y 7mo) with Angelman syndrome (seven male; seven female) and 13 typically developing children, aged 8 to 17 years, for comparison (five male; eight female; mean age 12y; SD 2y 9mo). Individuals with Angelman syndrome were assessed using standardized measures of development, language, and behaviour. RESULTS: The children with Angelman syndrome exhibited lower fractional anisotropy and increased radial diffusivity values than the comparison group for the AF, UF, ILF, and CC (p < 0.006 corrected for multiple comparisons). They also had lower fractional anisotropy values for the IFOF and higher radial diffusivity values for the left IFOF (p < 0.006). Additionally, children with Angelman syndrome had significantly higher apparent diffusion coefficient values in the AF, CC, ILF, and the left IFOF (p < 0.006). Significant correlations were noted between DTI parameters and some of the clinical assessment outcomes (e.g. language, socialization, cognition) for three of the temporal pathways (AF, UF, ILF; p < 0.05). INTERPRETATION: Changes in DTI parameters in individuals with Angelman syndrome suggest decreased/delayed myelination, decreased axonal density or diameter, or aberrant axonal organization. Our findings suggest a generalized white matter alteration throughout the brain in those with Angelman syndrome; however, only the alterations in temporal white matter pathways were associated with language and cognitive and social functioning.


Assuntos
Síndrome de Angelman/patologia , Encéfalo/patologia , Fibras Nervosas Mielinizadas/patologia , Vias Neurais/patologia , Adolescente , Análise de Variância , Síndrome de Angelman/genética , Anisotropia , Criança , Cromossomos Humanos Par 15/genética , Corpo Caloso/patologia , Imagem de Tensor de Difusão/métodos , Feminino , Lateralidade Funcional , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Testes Psicológicos , Estatística como Assunto
4.
Radiol Case Rep ; 5(3): 373, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-27307866

RESUMO

Precalcaneal soft-tissue lesions are uncommon in the pediatric population and can present a diagnostic challenge. Fibrous hamartoma of infancy (FHI) is relatively rare in this location. We report an interesting case of FHI in a 3-years-and-10-months-old boy in the precalcaneal location that was present since birth. We describe the imaging findings of FHI on X-ray, ultrasound, and MRI and discuss the differential diagnoses. It is important to consider FHI during differential diagnosis and be aware of the imaging features of other common possible diagnoses in the precalcaneal region for appropriate management.

5.
Pediatr Radiol ; 39(12): 1365-8, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19690849

RESUMO

Ewing sarcoma of the bone is a highly malignant round-cell tumor that typically presents between 10 to 20 years of age and is more common in boys. It can have an extraosseous origin, although it is rare. We report a case of extraosseous Ewing sarcoma in the thyroid gland in a 9-year-old girl.


Assuntos
Imageamento por Ressonância Magnética , Tomografia Computadorizada por Raios X , Ultrassonografia , Neoplasias Ósseas/diagnóstico , Criança , Feminino , Humanos , Sarcoma de Ewing/diagnóstico , Neoplasias da Glândula Tireoide/diagnóstico
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