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1.
AJR Am J Roentgenol ; 205(5): 1075-85, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26496556

RESUMO

OBJECTIVE: Tumefactive demyelinating lesions (TDLs) remain one of the most common brain lesions to mimic a brain tumor, particularly primary CNS lymphoma (PCNSL) and high-grade gliomas. The purpose of our study was to evaluate the ability of apparent diffusion coefficient (ADC) values and conventional MRI features to differentiate TDLs from PCNSLs and high-grade gliomas. MATERIALS AND METHODS: Seventy-five patients (24 patients with TDLs, 28 with PCNSLs, and 23 with high-grade gliomas) with 168 brain lesions (70 TDLs, 68 PCNSLs, and 30 high-grade gliomas) who underwent DWI before surgery or therapy were included in the study. Minimum ADC (ADC(min)) and average ADC (ADC(avg)) values were calculated for each lesion. ANOVA and ROC analyses were performed. ROC analyses were also performed for the presence of incomplete rim enhancement and for the number of lesions. Multiple-variable logistic regression with ROC analysis was then performed to evaluate performance in multiple-variable models. RESULTS: ADC(min) was statistically significantly higher (p < 0.01) in TDLs (mean, 0.886; 95% CI, 0.802-0.931) than in PCNSLs (0.547; 95% CI, 0.496-0.598) and high-grade gliomas (0.470; 95% CI, 0.385-0.555). (All ADC values in this article are reported in units of × 10(-3) mm(2)/s.) ADC(avg) was statistically significantly higher (p < 0.01) in TDLs (mean, 1.362; 95% CI, 1.268-1.456) than in PCNSLs (0.990; 95% CI, 0.919-1.061) but not in high-grade gliomas (1.216; 95% CI, 1.074-1.356). Multiple-variable models showed statistically significant individual effects and superior diagnostic performance on ROC analysis. CONCLUSION: TDLs can be diagnosed on preoperative MRI with a high degree of specificity; MRI features of incomplete rim enhancement, high ADC values, and a large number of lesions individually increase the probability and diagnostic confidence that a lesion is a TDL.


Assuntos
Neoplasias Encefálicas/diagnóstico , Doenças Desmielinizantes/diagnóstico , Imagem de Difusão por Ressonância Magnética/métodos , Glioma/diagnóstico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias Encefálicas/patologia , Meios de Contraste , Doenças Desmielinizantes/patologia , Diagnóstico Diferencial , Feminino , Glioma/patologia , Humanos , Interpretação de Imagem Assistida por Computador , Imageamento Tridimensional , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
2.
Neuroimage ; 54 Suppl 1: S196-203, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19761848

RESUMO

Optimal results in the direct brain delivery of brain therapeutics such as growth factors or viral vector into primate brain depend on reproducible distribution throughout the target region. In the present study, we retrospectively analyzed MRI of 25 convection-enhanced delivery (CED) infusions with MRI contrast into the putamen of non-human primates (NHP). Infused volume (V(i)) was compared to total volume of distribution (V(d)) versus V(d) within the target putamen. Excellent distribution of contrast agent within the putamen was obtained in eight cases that were used to define an optimal target volume or "green" zone. Partial or poor distribution with leakage into adjacent anatomical structures was noted in 17 cases, defining "blue" and "red" zones, respectively. Quantitative containment (99±1%) of infused gadoteridol within the putamen was obtained when the cannula was placed in the green zone, 87±3% in the blue zone and 49±0.05% in the red zone. These results were used to determine a set of 3D stereotactic coordinates that define an optimal site for putaminal infusions in NHP and human putamen. We conclude that cannula placement and definition of optimal (green zone) stereotactic coordinates have important implications in ensuring effective delivery of therapeutics into the putamen utilizing routine stereotactic MRI localization procedures and should be considered when local therapies such as gene transfer or protein administration are being translated into clinical therapy.


Assuntos
Meios de Contraste/administração & dosagem , Sistemas de Liberação de Medicamentos/métodos , Compostos Heterocíclicos/administração & dosagem , Compostos Organometálicos/administração & dosagem , Putamen/metabolismo , Cirurgia Assistida por Computador/métodos , Animais , Meios de Contraste/farmacocinética , Convecção , Feminino , Gadolínio , Compostos Heterocíclicos/farmacocinética , Humanos , Macaca fascicularis , Macaca mulatta , Imageamento por Ressonância Magnética , Masculino , Compostos Organometálicos/farmacocinética , Distribuição Tecidual
3.
J Neurosci Methods ; 176(2): 200-5, 2009 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-18809434

RESUMO

Convection-enhanced delivery (CED) has recently entered the clinic and represents a promising new delivery option for targeted gene therapy in Parkinson's disease (PD). The prime stereotactic target for the majority of recent gene therapy clinical trials has been the human putamen. The stereotactic delivery of therapeutic agents into putamen (or other subcortical structures) via CED remains problematic due to the difficulty in knowing what volume of therapeutic agent to deliver. Preclinical studies in non-human primates (NHP) offer a way to model treatment strategies prior to clinical trials. Understanding more accurately the volumetric differences in striatum, especially putamen, between NHP and humans is essential in predicting convective volume parameters in human clinical trials. In this study, magnetic resonance images (MRI) were obtained for volumetric measurements of striatum (putamen and caudate nucleus) and whole brain from 11 PD patients, 13 aged healthy human subjects, as well as 8 parkinsonian and 30 normal NHP. The human brain is 13-18 times larger than the monkey brain. However, this ratio is significantly smaller for striatum (5.7-6.5), caudate nucleus (4.6-6.6) and putamen (4.4-6.6). Size and species of the monkeys used for this comparative study are responsible for differences in ratios for each structure between monkeys and humans. This volumetric ratio may have important implications in the design of clinical therapies for PD and Huntington's disease and should be considered when local therapies such as gene transfer, local protein administration or cellular replacement are translated based on NHP research.


Assuntos
Corpo Estriado/patologia , Intoxicação por MPTP/patologia , Doença de Parkinson/patologia , Idoso , Animais , Feminino , Humanos , Macaca mulatta , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade
4.
J Neurosci Methods ; 196(1): 124-30, 2011 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-21185868

RESUMO

This comparative magnetic resonance imaging (MRI) analysis evaluated the ratio of AC-PC (anterior commissure to posterior commissure) distance measures in selected groups of humans and nonhuman primates (NHPs). An understanding of the basis of this ratio between primate species may allow more accurate translation of NHP stereotactic targeting measurements to upcoming human trials. MRI datasets of adult humans [n=21], and juvenile and adult NHPs (Macaca fascicularis [n=40], and Macaca mulatta [n=32]), were evaluated in a mid-sagittal plane to obtain the AC-PC distance measure for each examined subject. Two trained evaluators, blinded to each other's results, carried out three separate measurements of the AC-PC length for each subject. Each observer carried out measurements of the entire dataset [n=93] before repeating the measurements two additional times. Previous dataset measures were not available for review at the time of subsequent measures. Inter- and intra-observer variabilities were not statistically significant. Minimal intraspecies variation was found in the AC-PC measurement of our human and NHP groups. We found significant interspecies differences, however, more between humans and NHPs, and less between the NHP groups. Regression analysis confirms the strong linear relationship of AC-PC distance based primarily on species in our study groups. Human/NHP AC-PC ratios varied between 2.1 and 2.3 based on the compared NHP species groups. We conclude that the scale differences in brain measurements between NHPs and humans described in this study allows improved translation of stereotactic targeting coordinates in future human clinical trials, which may lead to improved efficacy and safety.


Assuntos
Mapeamento Encefálico/métodos , Mapeamento Encefálico/normas , Encéfalo/anatomia & histologia , Técnicas Estereotáxicas , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Animais , Encéfalo/patologia , Corpo Caloso/anatomia & histologia , Corpo Caloso/patologia , Feminino , Humanos , Processamento de Imagem Assistida por Computador/métodos , Modelos Lineares , Macaca fascicularis , Macaca mulatta , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Doença de Parkinson/patologia
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