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1.
AJNR Am J Neuroradiol ; 38(12): 2243-2250, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29074633

RESUMO

BACKGROUND AND PURPOSE: Glioblastoma is the most common primary brain malignancy and differentiation of true progression from pseudoprogression is clinically important. Our purpose was to compare the diagnostic performance of dynamic contrast-enhanced pharmacokinetic parameters using the fixed T1 and measured T1 on differentiating true from pseudoprogression of glioblastoma after chemoradiation with temozolomide. MATERIALS AND METHODS: This retrospective study included 37 patients with histopathologically confirmed glioblastoma with new enhancing lesions after temozolomide chemoradiation defined as true progression (n = 15) or pseudoprogression (n = 22). Dynamic contrast-enhanced pharmacokinetic parameters, including the volume transfer constant, the rate transfer constant, the blood plasma volume per unit volume, and the extravascular extracellular space per unit volume, were calculated by using both the fixed T1 of 1000 ms and measured T1 by using the multiple flip-angle method. Intra- and interobserver reproducibility was assessed by using the intraclass correlation coefficient. Dynamic contrast-enhanced pharmacokinetic parameters were compared between the 2 groups by using univariate and multivariate analysis. The diagnostic performance was evaluated by receiver operating characteristic analysis and leave-one-out cross validation. RESULTS: The intraclass correlation coefficients of all the parameters from both T1 values were fair to excellent (0.689-0.999). The volume transfer constant and rate transfer constant from the fixed T1 were significantly higher in patients with true progression (P = .048 and .010, respectively). Multivariate analysis revealed that the rate transfer constant from the fixed T1 was the only independent variable (OR, 1.77 × 105) and showed substantial diagnostic power on receiver operating characteristic analysis (area under the curve, 0.752; P = .002). The sensitivity and specificity on leave-one-out cross validation were 73.3% (11/15) and 59.1% (13/20), respectively. CONCLUSIONS: The dynamic contrast-enhanced parameter of rate transfer constant from the fixed T1 acted as a preferable marker to differentiate true progression from pseudoprogression.


Assuntos
Neoplasias Encefálicas/diagnóstico por imagem , Glioblastoma/diagnóstico por imagem , Adulto , Idoso , Antineoplásicos Alquilantes/uso terapêutico , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/terapia , Quimiorradioterapia , Meios de Contraste , Dacarbazina/análogos & derivados , Dacarbazina/uso terapêutico , Progressão da Doença , Feminino , Glioblastoma/patologia , Glioblastoma/terapia , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Curva ROC , Reprodutibilidade dos Testes , Estudos Retrospectivos , Sensibilidade e Especificidade , Temozolomida
2.
AJNR Am J Neuroradiol ; 38(11): 2052-2058, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28912280

RESUMO

BACKGROUND AND PURPOSE: In adults with only cerebellar masses, hemangioblastoma and metastasis are the 2 most important differential diagnoses. Our aim was to investigate the added value of arterial spin-labeling MR imaging for differentiating hemangioblastoma from metastasis in patients with only cerebellar masses. MATERIALS AND METHODS: This retrospective study included a homogeneous cohort comprising patients with only cerebellar masses, including 16 hemangioblastomas and 14 metastases. All patients underwent enhanced MR imaging, including arterial spin-labeling. First, the presence or absence of a hyperperfused mass was determined. Next, in the hyperperfused mass, relative tumor blood flow (mean blood flow in the tumor divided by blood flow measured in normal-appearing cerebellar tissue) and the size ratio (size in the arterial spin-labeling images divided by size in the postcontrast T1WI) were measured. To validate the arterial spin-labeling findings, 2 observers independently evaluated the conventional MR images and the combined set of arterial spin-labeling images. RESULTS: All patients with hemangioblastomas and half of the patients with metastases presented with a hyperperfused mass (P < .001). The size ratio and relative tumor blood flow were significantly larger for hemangioblastomas than for metastases (P < .001 and P = .039, respectively). The size ratio revealed excellent diagnostic power (area under the curve = 0.991), and the relative tumor blood flow demonstrated moderate diagnostic power (area under the curve = 0.777). The diagnostic accuracy of both observers was significantly improved after the addition of arterial spin-labeling; the area under the curve improved from 0.574 to 0.969 (P < .001) for observer 2 and from 0.683 to 1 (P < .001) for observer 2. CONCLUSIONS: Arterial spin-labeling imaging can aid in distinguishing hemangioblastoma from metastasis in patients with only cerebellar masses.


Assuntos
Neoplasias Cerebelares/diagnóstico por imagem , Neoplasias Cerebelares/secundário , Artérias Cerebrais/diagnóstico por imagem , Hemangioblastoma/diagnóstico por imagem , Hemangioblastoma/secundário , Imageamento por Ressonância Magnética/métodos , Marcadores de Spin , Adulto , Idoso , Área Sob a Curva , Neoplasias Cerebelares/irrigação sanguínea , Estudos de Coortes , Diagnóstico Diferencial , Feminino , Hemangioblastoma/irrigação sanguínea , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Fluxo Sanguíneo Regional , Reprodutibilidade dos Testes , Estudos Retrospectivos , Adulto Jovem
3.
AIDS Res Hum Retroviruses ; 16(11): 1083-7, 2000 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-10933624

RESUMO

Subtype E HIV-1 is the most prevalent strain in Southeast Asia. Although subtype B is prevalent in Korea, geographical distance and increases in travel may lead to the spread of subtype E in Korea. Therefore, we tried to identify and monitor the patterns of HIV subtype E virus introduction into Korea. The divergence of nucleotide sequences within the envelope region (V3 to V5) of Korean subtype E isolates ranged from 4.3 to 14.6% (n = 8; mean, 9.5 +/- 2.8%). In pairwise comparisons of subtype E isolates between Korea and other regions, the divergence of nucleotide sequences between 8 Korean and 16 Asian subtype E variants ranged from 1.3 to 15.2% (mean, 7.8 +/- 2.6%), whereas the divergence of nucleotide sequences between 8 Korean and 2 African variants ranged from 11.7 to 20.7% (mean, 15.4 +/- 2.2%). A phylogenetic tree showed that Korean subtype E isolates cluster with the Asian isolates but far from the African isolates. These epidemiological and molecular epidemiological data suggest that HIV-1 subtype E strains have been transmitted into Korea from endemic areas of Southeast Asia rather from Africa.


Assuntos
Infecções por HIV/epidemiologia , HIV-1/classificação , Adulto , Sequência de Aminoácidos , Feminino , Produtos do Gene env/química , Produtos do Gene env/genética , Genes env , Infecções por HIV/virologia , HIV-1/genética , Humanos , Coreia (Geográfico)/epidemiologia , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Filogenia , Análise de Sequência de DNA
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