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1.
Radiography (Lond) ; 30(3): 770-775, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38460224

RESUMO

INTRODUCTION: Implanted pacemakers (PM) would decrease the detection of lung nodules in chest computed tomography (CT) due to the metal artifact. This study aimed to explore the computer-aided diagnosis (CAD) detectability of pulmonary nodules for the patients implanted with PMs in low- and ultra-low-dose chest CT screening. METHODS: Four different sizes of artificial nodules were placed in an anthropomorphic chest phantom with two alternative diameters utilized. A commercially available PM was placed on the surface of the left chest wall of the phantom. The image acquisitions were performed with 120 kV and 150 kV with a dedicated selective photon shield made of tin filter (Sn150 kV) at low- and ultra-low- radiation doses (1.0 and 0.5 mGy of volume CT dose index), and reconstructed with and without Iterative Metal Artifact Reduction (iMAR, Siemens Healthineers, Erlangen, Germany). The relative artifact index (AIr) was calculated as an index of metal artifacts, and the nodule detectability was evaluated with a CAD system. RESULTS: Sn150 kV reduced AIr in all acquisitions when comparing 120 kV and Sn150 kV. Although PM reduced the detectability of nodules, Sn150 kV showed higher detectability compared to 120 kV. The use of iMAR showed inconsistent results in nodule detectability. CONCLUSION: Sn150 kV reduced PM-induced metal artifacts and improved nodule detectability with CAD compared to 120 kV acquisition in many conditions including low and ultra-low doses and large phantoms, but iMAR did not improve the detectability. IMPLICATIONS FOR PRACTICE: Based on the results of the current phantom study, low and ultra-low dose with Sn150 kV acquisition reduced PM-induced metal artifacts and improved nodule detectability.


Assuntos
Artefatos , Marca-Passo Artificial , Imagens de Fantasmas , Doses de Radiação , Tomografia Computadorizada por Raios X , Humanos , Tomografia Computadorizada por Raios X/métodos , Radiografia Torácica/métodos , Interpretação de Imagem Radiográfica Assistida por Computador/métodos
2.
Clin Radiol ; 74(10): 816.e1-816.e8, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31400805

RESUMO

AIM: To evaluate the diagnostic feasibility of probabilistic analysis using voxel-based morphometry (VBM) in differentiating primary central nervous system lymphoma (PCNSL) from glioblastoma (GBM). MATERIALS AND METHODS: In total, 118 patients with GBM (57 males, 61 females; mean [± standard deviation] age, 56.9±19.3 years; median, 61 years) and 52 patients with PCNSL (37 males, 15 females; mean age, 62±13.3 years, median, 66 years) were studied retrospectively. Each patient underwent preoperative contrast-enhanced T1-weighted imaging (CE-T1WI) using a 1.5 or 3 T magnetic resonance imaging (MRI) system. To assess preferential occurrence sites, images from CE-T1WI were co-registered and spatially normalised using the MNI152 T1 template. Subsequently, a region of interest (ROI) was placed in the centre of the enhancing tumour in normalised images with 1-mm isotropic resolution. The same ROI between normalised and T1 template images was set up using an ROI manager function in ImageJ software. A spherical volume of interest (VOI) with a radius of 10 mm was determined. A probability map was created by overlaying each image with the VOI. Each VOI was removed from T1 template images for VBM analysis. VBM analysis was performed using statistical parametric mapping (SPM) 12 software under default settings. RESULTS: VBM analysis showed significantly higher frequency in the splenium of the corpus callosum among PCNSL patients than among GBM patients (p<0.05; family-wise error correction). CONCLUSION: Topographic analysis using VBM provides useful information for differentiating PCNSL from GBM.


Assuntos
Mapeamento Encefálico , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias do Sistema Nervoso Central/diagnóstico por imagem , Glioblastoma/diagnóstico por imagem , Linfoma/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Meios de Contraste , Diagnóstico Diferencial , Estudos de Viabilidade , Feminino , Substância Cinzenta/diagnóstico por imagem , Humanos , Processamento de Imagem Assistida por Computador/métodos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto Jovem
3.
AJNR Am J Neuroradiol ; 40(5): 878-884, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-31023663

RESUMO

BACKGROUND AND PURPOSE: Intravoxel incoherent motion imaging, which simultaneously measures diffusion and perfusion parameters, is promising for brain tumor grading. However, intravoxel incoherent motion imaging has not been tested in children. The purpose of this study was to evaluate the correlation between intravoxel incoherent motion parameters and histology to assess the accuracy of intravoxel incoherent motion imaging for pediatric intracranial tumor grading. MATERIALS AND METHODS: Between April 2013 and September 2015, 17 children (11 boys, 6 girls; 2 months to 15 years of age) with intracranial tumors were included in this retrospective study. Intravoxel incoherent motion parameters were fitted using 13 b-values for a biexponential model. The perfusion-free diffusion coefficient, pseudodiffusion coefficient, and perfusion fraction were measured in high- and low-grade tumors. These intravoxel incoherent motion parameters and the ADC were compared using the unpaired t test. The correlations between the intravoxel incoherent motion parameters and microvessel density or the MIB-1 index were analyzed using the Spearman correlation test. Receiver operating characteristic analysis was used to evaluate diagnostic performance. RESULTS: The perfusion-free diffusion coefficient and ADC were lower in high-grade than in low-grade tumors (perfusion-free diffusion coefficient, 0.85 ± 0.40 versus 1.53 ± 0.21 × 10-3 mm2/s, P < .001; ADC, 1.04 ± 0.33 versus 1.60 ± 0.21 × 10-3 mm2/s, P < .001). The pseudodiffusion coefficient showed no difference between the groups. The perfusion fraction was higher in high-grade than in low-grade tumors (21.7 ± 8.2% versus 7.6 ± 4.3%, P < .001). Receiver operating characteristic analysis found that the combined perfusion-free diffusion coefficient and perfusion fraction had the best diagnostic performance for tumor differentiation (area under the curve = 0.986). CONCLUSIONS: Intravoxel incoherent motion imaging reflects tumor histology and may be a helpful, noninvasive method for pediatric intracranial tumor grading.


Assuntos
Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/patologia , Imagem de Difusão por Ressonância Magnética/métodos , Interpretação de Imagem Assistida por Computador/métodos , Neuroimagem/métodos , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Movimento (Física) , Gradação de Tumores/métodos , Estudos Retrospectivos
4.
Diagn Interv Imaging ; 100(7-8): 411-419, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30948344

RESUMO

PURPOSE: The purpose of this study was to identify magnetic resonance imaging (MRI) features that are associated with telomerase reverse transcriptase promoter mutation (TERTm) in glioblastoma. MATERIALS AND METHODS: A total of 112 patients with glioblastoma who had MRI at 1.5- or 3.0-T were retrospectively included. There were 43 patients with glioblastoma with wild-type TERT (TERTw) (22 men, 21 women; mean age, 47±25 [SD] years; age range: 3-84 years) and 69 patients with glioblastoma with TERTm (34 men, 35 women; mean age 64±11 [SD] years; age range, 41--85 years). The feature vectors consist of 11 input units for two clinical parameters (age and gender) and nine MRI characteristics (tumor location, subventricular extension, cortical extension, multiplicity, enhancing volume, necrosis volume, the percentage of necrosis volume, minimum apparent diffusion coefficient [ADC] and normalized ADC). First, the diagnostic performance using univariate and multivariate logistic regression analyses was evaluated. Second, the cross-validation of the support vector machine (SVM) was performed by using leave-one-out method with 43 TERTw and 69 TERTm to evaluate the diagnostic performance. In addition, the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy for the differentiation between TERTw and TERTm were compared between logistic regression analysis and SVM. RESULTS: With multivariate analysis, the percentage of necrosis volume and age were significantly greater in TERTm glioblastoma than in TERTw glioblastoma. SVM allowed discriminating between TERTw glioblastoma and TERTm glioblastoma with sensitivity, specificity, PPV, NPV, and accuracy of 85.7% [60/70; 95% confidence interval (CI): 75.3-92.9%], 54.8% (23/42; 95% CI: 38.7-70.2%), 75.9% (60/79; 95% CI: 69.1-81.7%), 69.7% (23/33; 95% CI: 54.9-81.3%) and 74.1% (83/112; 95% CI: 65.0-81.9%), respectively. CONCLUSION: The percentage of necrosis volume and age may surrogate for predicting TERT mutation status in glioblastoma.


Assuntos
Neoplasias Encefálicas/diagnóstico por imagem , Glioblastoma/diagnóstico por imagem , Imageamento por Ressonância Magnética , Mutação , Regiões Promotoras Genéticas , Telomerase , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Criança , Pré-Escolar , Meios de Contraste , Feminino , Glioblastoma/genética , Glioblastoma/patologia , Humanos , Isocitrato Desidrogenase/genética , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Necrose , Valor Preditivo dos Testes , Estudos Retrospectivos , Sensibilidade e Especificidade , Máquina de Vetores de Suporte , Adulto Jovem
6.
AJNR Am J Neuroradiol ; 37(1): 58-65, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26405082

RESUMO

BACKGROUND AND PURPOSE: Glioblastoma multiforme is highly aggressive and the most common type of primary malignant brain tumor in adults. Imaging biomarkers may provide prognostic information for patients with this condition. Patients with glioma with isocitrate dehydrogenase 1 (IDH1) mutations have a better clinical outcome than those without such mutations. Our purpose was to investigate whether the IDH1 mutation status in glioblastoma multiforme can be predicted by using MR imaging. MATERIALS AND METHODS: We retrospectively studied 55 patients with glioblastoma multiforme with wild type IDH1 and 11 patients with mutant IDH1. Absolute tumor blood flow and relative tumor blood flow within the enhancing portion of each tumor were measured by using arterial spin-labeling data. In addition, the maximum necrosis area, the percentage of cross-sectional necrosis area inside the enhancing lesions, and the minimum and mean apparent diffusion coefficients were obtained from contrast-enhanced T1-weighted images and diffusion-weighted imaging data. Each of the 6 parameters was compared between patients with wild type IDH1 and mutant IDH1 by using the Mann-Whitney U test. The performance in discriminating between the 2 entities was evaluated by using receiver operating characteristic analysis. RESULTS: Absolute tumor blood flow, relative tumor blood flow, necrosis area, and percentage of cross-sectional necrosis area inside the enhancing lesion were significantly higher in patients with wild type IDH1 than in those with mutant IDH1 (P < .05 each). In contrast, no significant difference was found in the ADC(minimum) and ADC(mean). The area under the curve for absolute tumor blood flow, relative tumor blood flow, percentage of cross-sectional necrosis area inside the enhancing lesion, and necrosis area were 0.850, 0.873, 0.739, and 0.772, respectively. CONCLUSIONS: Tumor blood flow and necrosis area calculated from MR imaging are useful for predicting the IDH1 mutation status.


Assuntos
Neoplasias Encefálicas/genética , Imagem de Difusão por Ressonância Magnética/métodos , Glioblastoma/genética , Isocitrato Desidrogenase/genética , Adulto , Idoso , Área Sob a Curva , Neoplasias Encefálicas/irrigação sanguínea , Neoplasias Encefálicas/patologia , Estudos Transversais , Feminino , Glioblastoma/irrigação sanguínea , Glioblastoma/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Prognóstico , Curva ROC , Estudos Retrospectivos , Marcadores de Spin
7.
Clin Neuroradiol ; 26(2): 229-33, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26170221

RESUMO

We report a case of leiomyosarcoma of the thoracic spine. Primary leiomyosarcoma is a malignant connective tissue tumor originating from smooth muscle cells. Leiomyosarcoma frequently occurs in the uterus, retroperitoneal space, gastrointestinal tract, and deep soft tissues; primary leiomyosarcoma of the bone is rare. The MR imaging including intravoxel incoherent motion (IVIM) imaging findings of the current case indicated a low diffusion coefficient and high blood flow, which were in concurrence with high cell density on histology and increased vascularity by angiography. Although some benign tumors such as osteoblastoma and giant cell tumor would show similar findings on IVIM imaging, these additional imaging features may narrow the differential diagnosis of spinal tumors.


Assuntos
Leiomiossarcoma/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Neoplasias da Coluna Vertebral/diagnóstico por imagem , Vértebras Torácicas/diagnóstico por imagem , Diagnóstico Diferencial , Feminino , Humanos , Leiomiossarcoma/patologia , Pessoa de Meia-Idade , Neoplasias da Coluna Vertebral/patologia , Vértebras Torácicas/patologia
8.
AJNR Am J Neuroradiol ; 32(10): 1915-8, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21778245

RESUMO

BACKGROUND AND PURPOSE: Previous reports have shown that DWI is useful in detecting cholesteatoma. SS-EPI is the most widely used DWI technique. However, SS-EPI may have susceptibility artifacts due to field inhomogeneity in the imaging of the temporal bone region. Our purpose was to prospectively evaluate the advantage of MS-EPI for the diagnosis of middle ear cholesteatoma by comparing it with SS-EPI. MATERIALS AND METHODS: We studied 29 patients with preoperatively suspected acquired cholesteatoma. Each patient underwent an MR imaging examination including both SS-EPI and MS-EPI by using a 1.5T MR imaging scanner. Images of the 29 patients (58 temporal bones including 30 with and 28 without cholesteatoma) were reviewed by 2 independent neuroradiologists. The confidence level for the presence of cholesteatoma was graded on a scale of 0-2 (0 = none, 1 = equivocal, 2 = definite). Interobserver agreement as well as sensitivity, specificity, and accuracy were assessed for the 2 readers. RESULTS: Excellent interobserver agreement was shown for both MS-EPI (κ = 0.856) and SS-EPI (κ = 0.820). MS-EPI was associated with higher sensitivity (76.7%) and accuracy (87.9%) than SS-EPI (sensitivity = 50.0%, accuracy = 74.1%) (P < .05), while both methods showed 100% specificity. CONCLUSIONS: Compared with SS-EPI, MS-EPI improves the accuracy of the diagnosis of acquired middle ear cholesteatomas.


Assuntos
Colesteatoma da Orelha Média/diagnóstico , Imagem de Difusão por Ressonância Magnética/métodos , Imagem Ecoplanar/métodos , Aumento da Imagem/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Adulto Jovem
9.
AJNR Am J Neuroradiol ; 32(4): 664-70, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21292797

RESUMO

BACKGROUND AND PURPOSE: MSDE preparation is a technique for black-blood imaging. Our purpose was to evaluate the usefulness of a 3D TSE sequence with MSDE preparation in detecting brain metastases by comparing it with conventional sequences. MATERIALS AND METHODS: Postcontrast images of 227 patients who were suspected of having brain metastasis were prospectively obtained by using 3 T1-weighted 3D sequences: a gradient-echo sequence (MPRAGE), TSE-noMSDE, and TSE-MSDE. The number of visualized blood vessels and the lesion-to-normal CNR were compared among the 3 sequences. An observer test involving 9 radiologists was performed, and their diagnostic performance by using TSE-MSDE, MPRAGE, and combined TSE-MSDE and MPRAGE was compared by means of an FOM as an index of diagnostic performance derived by the JAFROC analysis, sensitivity, FP/case, and reading time. RESULTS: TSE-MSDE resulted in significantly better vessel suppression than the other 2 methods. TSE with and without MSDE resulted in significantly higher CNRs than MPRAGE. In the observer test, significantly higher sensitivity and FOM as well as significantly shorter reading time were achieved by TSE-MSDE compared with MPRAGE, but FP/case was significantly higher with TSE-MSDE. Combined TSE-MSDE/MPRAGE resulted in significantly higher sensitivity and FOM and similar FP/case and reading time compared with MPRAGE alone. CONCLUSIONS: With blood vessel suppression and increased CNR, TSE-MSDE improves radiologists' performances in detecting brain metastases compared with MPRAGE, but it may increase FP results. Combined with MPRAGE, TSE-MSDE achieves high diagnostic performance while maintaining a low FP rate.


Assuntos
Neoplasias Encefálicas/secundário , Imagem Ecoplanar/métodos , Imagem Ecoplanar/normas , Neoplasias Pulmonares/patologia , Neurorradiografia/normas , Adulto , Idoso , Idoso de 80 Anos ou mais , Artefatos , Neoplasias da Mama/patologia , Artérias Cerebrais/anatomia & histologia , Bases de Dados Factuais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Bucais/patologia , Neurorradiografia/estatística & dados numéricos , Variações Dependentes do Observador , Neoplasias Pancreáticas/patologia , Estudos Prospectivos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
10.
AJNR Am J Neuroradiol ; 29(6): 1153-8, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18388216

RESUMO

BACKGROUND AND PURPOSE: Previous studies have suggested that use of an artificial neural network (ANN) system is beneficial for radiological diagnosis. Our purposes in this study were to construct an ANN for the differential diagnosis of intra-axial cerebral tumors on MR images and to evaluate the effect of ANN outputs on radiologists' diagnostic performance. MATERIALS AND METHODS: We collected MR images of 126 patients with intra-axial cerebral tumors (58 high-grade gliomas, 37 low-grade gliomas, 19 metastatic tumors, and 12 malignant lymphomas). We constructed a single 3-layer feed-forward ANN with a Levenberg-Marquardt algorithm. The ANN was designed to differentiate among 4 categories of tumors (high-grade gliomas, low-grade gliomas, metastases, and malignant lymphomas) with use of 2 clinical parameters and 13 radiologic findings in MR images. Subjective ratings for the 13 radiologic findings were provided independently by 2 attending radiologists. All 126 cases were used for training and testing of the ANN based on a leave-one-out-by-case method. In the observer test, MR images were viewed by 9 radiologists, first without and then with ANN outputs. Each radiologist's performance was evaluated through a receiver operating characteristic (ROC) analysis on a continuous rating scale. RESULTS: The averaged area under the ROC curve for ANN alone was 0.949. The diagnostic performance of the 9 radiologists increased from 0.899 to 0.946 (P < .001) when they used ANN outputs. CONCLUSIONS: The ANN can provide useful output as a second opinion to improve radiologists' diagnostic performance in the differential diagnosis of intra-axial cerebral tumors seen on MR imaging.


Assuntos
Neoplasias Encefálicas/diagnóstico , Interpretação de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Redes Neurais de Computação , Reconhecimento Automatizado de Padrão/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
11.
AJNR Am J Neuroradiol ; 29(4): 688-93, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18184842

RESUMO

BACKGROUND AND PURPOSE: We investigated the relationship between tumor blood-flow measurement based on perfusion imaging by arterial spin-labeling (ASL-PI) and histopathologic findings in brain tumors. MATERIALS AND METHODS: We used ASL-PI to examine 35 patients with brain tumors, including 11 gliomas, 9 meningiomas, 9 schwannomas, 1 diffuse large B-cell lymphoma, 4 hemangioblastomas, and 1 metastatic brain tumor. As an index of tumor perfusion, the relative signal intensity (SI) of each tumor (%Signal intensity) was determined as a percentage of the maximal SI within the tumor per averaged SI within normal cerebral gray matter on ASL-PI. Relative vascular attenuation (%Vessel) was determined as the total microvessel area per the entire tissue area on CD-34-immunostained histopathologic specimens. MIB1 indices of gliomas were also calculated. The differences in %Signal intensity among different histopathologic types and between high- and low-grade gliomas were compared. In addition, the correlations between %Signal intensity and %Vessel or MIB1 index were evaluated in gliomas. RESULTS: Statistically significant differences in %Signal intensity were observed between hemangioblastomas versus gliomas (P < .005), meningiomas (P < .05), and schwannomas (P < .005). Among gliomas, %Signal intensity was significantly higher for high-grade than for low-grade tumors (P < .05). Correlation analyses revealed significant positive correlations between %Signal intensity and %Vessel in 35 patients, including all 6 histopathologic types (rs = 0.782, P < .00005) and in gliomas (rs = 0.773, P < .05). In addition, in gliomas, %Signal intensity and MIB1 index were significantly positively correlated (rs = 0.700, P < .05). CONCLUSION: ASL-PI may predict histopathologic vascular densities of brain tumors and may be useful in distinguishing between high- and low-grade gliomas and in differentiating hemangioblastomas from other brain tumors.


Assuntos
Neoplasias Encefálicas/irrigação sanguínea , Imageamento por Ressonância Magnética , Adolescente , Adulto , Idoso , Neoplasias Encefálicas/patologia , Proliferação de Células , Circulação Cerebrovascular , Criança , Pré-Escolar , Feminino , Glioma/irrigação sanguínea , Glioma/patologia , Hemangioma/irrigação sanguínea , Hemangioma/patologia , Humanos , Masculino , Neoplasias Meníngeas/irrigação sanguínea , Neoplasias Meníngeas/patologia , Meningioma/irrigação sanguínea , Meningioma/patologia , Microcirculação/patologia , Pessoa de Meia-Idade , Neurilemoma/irrigação sanguínea , Neurilemoma/patologia , Marcadores de Spin
12.
Acta Radiol ; 41(5): 417-9, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11016757

RESUMO

A 53-year-old Japanese woman presented with a mass of the hard palate that was histologically diagnosed as myoepithelioma. By CT, the well-demarcated ovoid isodense mass showed faint contrast enhancement. By MR imaging, the mass was homogeneous and isointense on T1-weighted images with homogeneous enhancement after administration of contrast material and markedly hyperintense on T2-weighted images. Myoepithelioma should be kept in mind as differential diagnosis of hard palatine tumors.


Assuntos
Diagnóstico por Imagem , Mioepitelioma/diagnóstico , Neoplasias Palatinas/diagnóstico , Actinas/análise , Meios de Contraste , Diagnóstico Diferencial , Feminino , Gadolínio DTPA , Humanos , Aumento da Imagem , Queratinas/análise , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Mioepitelioma/diagnóstico por imagem , Mioepitelioma/patologia , Neoplasias Palatinas/diagnóstico por imagem , Neoplasias Palatinas/patologia , Intensificação de Imagem Radiográfica , Proteínas S100/análise , Tomografia Computadorizada por Raios X , Vimentina/análise
13.
AJNR Am J Neuroradiol ; 20(10): 1976-8, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10588129

RESUMO

We report an unusual case of Kimura's disease. An 81-year-old Japanese woman was shown to have bilateral auricular masses that had begun to enlarge 6 years before. On CT scans, slightly high-density masses with faint contrast enhancement were seen. The masses were heterogeneous and hypointense on T1-weighted MR images, were slightly hyperintense on T2-weighted MR images, and showed heterogeneous enhancement after the administration of contrast material. Kimura's disease should be included in the differential diagnosis of bilateral auricular tumors.


Assuntos
Hiperplasia Angiolinfoide com Eosinofilia/diagnóstico , Otopatias/diagnóstico , Imageamento por Ressonância Magnética , Tomografia Computadorizada por Raios X , Idoso , Idoso de 80 Anos ou mais , Diagnóstico Diferencial , Orelha Externa/patologia , Feminino , Humanos , Aumento da Imagem
14.
Abdom Imaging ; 24(4): 357-9, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10390556

RESUMO

A rare case with a pseudolesion in segment II of the liver observed on computed tomography (CT) during arterial portography caused by the aberrant left gastric venous drainage is presented. Close observation of the celiac angiography was helpful in recognizing this pseudolesion. Selective catheterization of the left gastric artery and CT during its venous phase confirmed the etiology of the pseudolesion.


Assuntos
Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/secundário , Estômago/irrigação sanguínea , Tomografia Computadorizada por Raios X , Evolução Fatal , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Neoplasias Pancreáticas/patologia , Portografia , Veias/anormalidades
15.
Arch Biochem Biophys ; 264(1): 23-9, 1988 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-3395121

RESUMO

Mature bovine adrenocortical ferredoxin (adreno-ferredoxin) was extracted from fresh adrenal glands at pH 9.0. Extraction and purification at this alkaline pH protected the mature adreno-ferredoxin molecule from proteolytic degradation. The mature adreno-ferredoxin was extensively purified by a rapid procedure including two kinds of column chromatography, hydrophobic and ion exchange. The purified adreno-ferredoxin was homogeneous on the basis of two HPLC analyses, hydrophobic and ion exchange, and had the highest purity so far reported. Then it was digested by trypsin and the carboxyl-terminal peptide was isolated from the tryptic digest by a novel column chromatographic method using a cation-exchange HPLC column, TSK-gel SP-5PW. The carboxyl-terminal amino acid was isoleucine, so the adreno-ferredoxin had 127 amino acid residues, the longest polypeptide so far determined chemically for bovine adreno-ferredoxin. Only Glu-128 was lacking within the carboxyl-terminal elongated peptide that was found by nucleotide sequencing of the adreno-ferredoxin gene. There was no evidence obtained on whether the deletion of Glu-128 was due to so-called carboxyl-terminal processing or to proteolytic degradation during storage and purification.


Assuntos
Córtex Suprarrenal/análise , Ferredoxinas/isolamento & purificação , Elongação Traducional da Cadeia Peptídica , Sequência de Aminoácidos , Aminoácidos/isolamento & purificação , Animais , Bovinos , Fracionamento Químico , Cromatografia Líquida de Alta Pressão , Cromatografia por Troca Iônica , Dados de Sequência Molecular , Fragmentos de Peptídeos/isolamento & purificação
16.
Clin Chim Acta ; 160(3): 255-63, 1986 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-3791635

RESUMO

We studied the mitochondrial cytochrome P-450-linked monooxygenase system in livers of two patients with cerebrotendinous xanthomatosis (CTX). The three components of this system, which catalyzes steroid 27-hydroxylation, NADPH-hepatoredoxin reductase, hepatoredoxin, and cytochrome P-450s27, were stained on a nitrocellulose sheet with antibodies against NADPH-adrenodoxin reductase, adrenodoxin, and cytochrome P-450scc, respectively, from bovine adrenocortical mitochondria. The concentrations of hepatoredoxin in the patients were not significantly different from a control, but the level of NADPH-hepatoredoxin reductase was three times that of the control. Cytochrome P-450s27 was not detected in the patients, but it was present (22.8 pmol/mg of protein) in the control liver. This implies that a defect of mitochondrial cytochrome P-450s27 prevents steroid 27-hydroxylation of hepatic mitochondria in patients with CTX.


Assuntos
Encefalopatias/enzimologia , Sistema Enzimático do Citocromo P-450/análise , Ferredoxina-NADP Redutase/análise , Ferredoxinas/análise , Isoenzimas/análise , Mitocôndrias Hepáticas/enzimologia , NADH NADPH Oxirredutases/análise , Oxigenases/análise , Xantomatose/enzimologia , Córtex Suprarrenal/enzimologia , Córtex Suprarrenal/ultraestrutura , Adulto , Animais , Encefalopatias/complicações , Bovinos , Colestanotriol 26-Mono-Oxigenase , Sistema Enzimático do Citocromo P-450/metabolismo , Feminino , Humanos , Esteroide Hidroxilases/metabolismo , Tendões , Xantomatose/complicações
17.
Biochim Biophys Acta ; 580(1): 44-63, 1979 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-121057

RESUMO

Adrenocortical NADPH-cytochrome P-450 reductase (EC. 1.6.2.4) was purified from bovine adrenocortical microsomes by detergent solubilization and affinity chromatography. The purified cytochrome P-450 reductase was a single protein band in sodium dodecyl sulfate-polyacrylamide gel electrophoresis, being electrophoretically homogeneous and pure. The cytochrome P-450 reductase was optically a typical flavoprotein. The absorption peaks were at 274, 380 and 45 nm with shoulders at 290, 360 and 480 nm. The NADPH-cytochrome P-450 reductase was capable of reconstituting the 21-hydroxylase activity of 17 alpha-hydroxyprogesterone in the presence of cytochrome P-45021 of adrenocortical microsomes. The specific activity of the 21-hydroxylase of 17 alpha-hydroxyprogesterone in the reconstituted system using the excess concentration of the cytochrome P-450 reductase, was 15.8 nmol/min per nmol of cytochrome P-45021 at 37 degrees C. The NADPH-cytochrome P-450 reductase, like hepatic microsomal NADPH-cytochrome P-450 reductase, could directly reduce the cytochrome P-45021. The physicochemical properties of the NADPH-cytochrome P-450 reductase were investigated. Its molecular weight was estimated to be 80 000 +/- 1000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and analytical ultracentrifugation. The cytochrome P-450 reductase contained 1 mol each FAD and FMN as coenzymes. Iron, manganese, molybdenum and copper were not detected. The Km values of NADPH and NADH for the NADPH-cytochrome c reductase activity and those of cytochrome c for the activity of NADPH-cytochrome P-450 reductase were determined kinetically. They were 5.3 microM for NADPH, 1.1 mM for NADH, and 9-24 microM for cytochrome c. Chemical modification of the amino acid residues showed that a histidyl and cysteinyl residue are essential for the binding site of NADPH of NADPH-cytochrome P-450 reductase.


Assuntos
Córtex Suprarrenal/enzimologia , Microssomos/enzimologia , NADPH-Ferri-Hemoproteína Redutase/isolamento & purificação , Animais , Sítios de Ligação , Bovinos , Fenômenos Químicos , Físico-Química , Dicroísmo Circular , Cinética , Oxirredução , Solubilidade , Espectrometria de Fluorescência
18.
J Biochem ; 84(5): 1071-86, 1978 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32168

RESUMO

Pig NADPH-adrenodoxin reductase was crystallized from pig adrenocortical mitochondria and its physicochemical properties were investigated. Pig NADPH-adrenodoxin reductase is a typical flavoprotein. Its optical absorption spectrum showed peaks at 272, 377, and 450 nm in the oxidized form. The adrenodoxin reductase contained one FAD per mol. The molecular weight was 49,000. The isoelectric points of the adrenodoxin reductase and its complex with adrenodoxin were 5.3 and 4.6, respectively. Pig NADPH-adrenodoxin reductase, unlike bovine NADPH-adrenodoxin reductase, was found to be free of carbohydrate. The fluorescences of tryptophanyl residues and FAD of the adrenodoxin reductase were quenched by holo- and apo-adrenodoxins. The NADPH-binding site of the adrenodoxin reductase was examined by photooxidation and selective chemical modifications with diethyl pyrocarbonate and sulfhydryl reagents. The results indicate that a histidyl and a cysteinyl residue of the adrenodoxin reductase are essential for the NADPH-binding site. The circular dichroism spectrum of the adrenodoxin reductase showed negative ellipticity in the visible region. Spur formation was observed between pig and bovine NADPH-adrenodoxin reductases against the antibody to bovine NADPH-adrenodoxin reductase in Ouchterlony double-diffusion agar plates. The antibody did not interact with spinach ferredoxin-NADP+ reductase.


Assuntos
Córtex Suprarrenal/enzimologia , Adrenodoxina/metabolismo , Cisteína , Ferredoxina-NADP Redutase/metabolismo , Histidina , Mitocôndrias/enzimologia , NADH NADPH Oxirredutases/metabolismo , NADP/metabolismo , Animais , Sítios de Ligação , Bovinos , Dietil Pirocarbonato/farmacologia , Ferredoxina-NADP Redutase/imunologia , Ferredoxinas/farmacologia , Reagentes de Sulfidrila/farmacologia , Suínos
19.
Biochemistry ; 15(14): 3091-7, 1976 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-8083

RESUMO

The binding site of NADPH in NADPH-adrenodoxin reductase was examined using crystalline enzyme from bovine adrenocortical mitochondria by studies on the effects of photooxidation and chemical modifications of amino acid residues in the reductase. (1) Photoxication decreased the enzymatic activity of NADPH-adrenodoxin reductase. Photooxidation of the reductase was prevented by NADP+, adrenodoxin, or reduced glutathione, but not NAD+. Photoinactivation caused loss of a histidyl residue, but not of tyrosyl, tryptophanyl, cysteinyl, or methionyl residues of the reductase. It did not affect the circular dichroism spectrum of the reductase appreciably. (2) NADPH-adrenodoxin reductase activity was inhibited by diethyl pyrocarbonate and the inhibition was partially reversed by addition of hydroxylamine. The inhibition was prevented by NADP+, but not NAD+. (3) NADPH-adrenodoxin reductase activity was inhibited by 5,5'-dithiobis(2-nitrobenzoate) and the inhibition was reversed by reduced glutathione. It was also protected by NADP+, but not NAD+. The results indicate that a histidyl residue and a cysteinyl residue of NADPH-adrenodoxin reductase are essential for the binding of NADPH by the reductase.


Assuntos
Córtex Suprarrenal/enzimologia , Glândulas Suprarrenais/enzimologia , Cisteína , Ferredoxina-NADP Redutase/metabolismo , Histidina , NADH NADPH Oxirredutases/metabolismo , NADP/farmacologia , Adrenodoxina/farmacologia , Animais , Sítios de Ligação , Bovinos , Dietil Pirocarbonato/farmacologia , Ferredoxina-NADP Redutase/efeitos da radiação , Glutationa/farmacologia , Concentração de Íons de Hidrogênio , Hidroxilaminas/farmacologia , Luz , Azul de Metileno , Mitocôndrias/enzimologia , NAD/farmacologia
20.
Biochemistry ; 15(14): 3082-90, 1976 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-986153

RESUMO

A crystalline NADPH-adrenodoxin reductase was obtained from bovine adrenocortical mitochondria and its properties were investigated. Its molecular weights and isoelectric point were estimated to be 51 000 and 5.4, respectively. Amino acid and sugar contents and the interaction between the apo-reductase and flavin of NADPH-adrenodoxin reductase were investigated. Formation of a complex of bovine NADPH-adrenodoxin reductase with adrenodoxin, its apoadrenodoxin, or other non-heme iron proteins caused quenching of fluorescence of the tryptophanyl residue and bound FAD of the NADPH-adrenodoxin reductase. The results obatined suggest that adrenodoxin and apoadrenodoxin bind functionally to a site close to the tryptophanyl residue and the bound FAD of the reductase. The circular dichroism spectrum of oxidized NADPH-adrenodoxin reductase was measured in the ultraviolet and visible regions. This spectrum showed negative absorption in the visible region and was not appreciably influenced in either the ultraviolet or visible region by formation of a complex with adrenodoxin or apoadrenodoxin.


Assuntos
Córtex Suprarrenal/enzimologia , Glândulas Suprarrenais/enzimologia , Ferredoxina-NADP Redutase/metabolismo , Hemeproteínas/metabolismo , Mitocôndrias/enzimologia , NADH NADPH Oxirredutases/metabolismo , Adrenodoxina/metabolismo , Aminoácidos/análise , Animais , Apoproteínas/metabolismo , Sítios de Ligação , Carboidratos/análise , Bovinos , Ferredoxina-NADP Redutase/isolamento & purificação , Flavina-Adenina Dinucleotídeo/farmacologia , Peso Molecular , Ligação Proteica , Espectrometria de Fluorescência , Termodinâmica , Triptofano
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