Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 215
Filtrar
1.
Hand Surg Rehabil ; 37(3): 167-170, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29580686

RESUMO

We investigated the relationship between pain and hesitation during movement initiation among 11 adult female patients who had undergone surgery for a distal radius fracture. Data on the patients' pain at rest, pain during movement and score on the Pain Catastrophizing Scale were analyzed. Movement characteristics were assessed by the administration of a finger tapping (FT) task using the thumb and index finger, with the movement repeated 10 times, recorded and analyzed to determine the patient's hesitation when opening or closing her thumb/forefinger during the task. Hesitation of movement initiation was significantly correlated with subjective factors such as pain at rest, pain during movement, and rumination. Pain was not significantly correlated with the physical range of motion. Our findings suggest that hesitation during movement initiation for the FT task may be a type of behavior that is affected by subjective pain. Movement hesitation is a novel clinical sign indicating the possible progression of acute pain into chronic pain. The kinematic evaluation described herein is a convenient clinical measurement that captures a subjective factor.


Assuntos
Movimento/fisiologia , Dor/psicologia , Fraturas do Rádio/psicologia , Idoso , Feminino , Fixação de Fratura , Humanos , Dor/fisiopatologia , Período Pós-Operatório , Fraturas do Rádio/fisiopatologia , Fraturas do Rádio/cirurgia , Escala Visual Analógica
2.
EJVES Short Rep ; 38: 1-3, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29276786

RESUMO

INTRODUCTION: Vasculopathy, such as an aneurysm, stenosis, rupture, or arteriovenous fistula, in patients with neurofibromatosis type I (NF-1; von Recklinghausen disease) is well recognised. However, there has been no report regarding treatment for a ruptured lumbar artery aneurysm associated with NF-1. We present the first report of successful endovascular treatment by coil embolisation for a ruptured lumbar artery aneurysm in a patient with NF-I. REPORT: A 52 year old man with a history of NF-1 was referred with back pain and anaemia. The computed tomography scan showed rupture of a solitary lumbar artery aneurysm. The rupture was successfully treated by endovascular embolisation with a coil and N-butyl-2-cyanoacrylate. DISCUSSION: Endovascular treatment with coil embolisation was performed safely in this patient.

3.
Water Sci Technol ; 62(8): 1807-12, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20962396

RESUMO

Underground is an important space that supports function of cities, such as subways, shopping malls and basement parking. However in consequence a new type of disaster, the "urban flood" menaces these spaces. In the last decade, urban floods struck Tokyo, Nagoya and Fukuoka. When underground inundation occurs, people must evacuate to the ground as soon as possible. But, when such an inundation situation happens, aged persons may not be able to evacuate quickly to ground level. In this paper, the method of safety assessment for aged persons is discussed on the experimental results and flood simulation data in an underground space. As a criterion of the safety evacuation, the specific force per unit width is used in this study. From the result of experiments, it is difficult to implement safety evacuation when the specific force per unit width is over 0.100 m(2) for the aged male.


Assuntos
Planejamento em Desastres/métodos , Inundações , Modelos Teóricos , Trabalho de Resgate/métodos , Urbanização , Idoso , Idoso de 80 Anos ou mais , Simulação por Computador , Humanos , Japão , Segurança , Caminhada , Movimentos da Água
4.
Br J Radiol ; 81(962): 99-106, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18238921

RESUMO

The aim of this study was to assess the effects of the reconstructed thickness of axial images on image quality of CT pancreatic arteriography with 16-channel multislice CT. In 31 consecutive patients, raw data of arterial-phase scanning with 0.5 mm collimation were reconstructed in the following three ways: 0.5 mm thickness (effective thickness of 0.75 mm) at 0.4 mm intervals in Group 1; 1 mm thickness at 0.5 mm intervals in Group 2; and 2 mm thickness at 1 mm intervals in Group 3. For the visualization of major arteries and small arteries of the pancreatic head, four blinded readers independently performed side-by-side comparison of the CT arteriographic images generated from each axial dataset for the same patient using a three-dimensional volume-rendered technique. In all comparisons using a continuous rating scale, CT arteriographic images generated from thinner axial images were found to be significantly superior (p<0.01). The difference was more pronounced for small arteries. The degree of degradation from Group 1 to Group 2 was markedly smaller than that from Group 1 to Group 3 or from Group 2 to Group 3. For small arteries, paired images were assigned a grade of "almost equivalent" in 73%, 6% and 15% of the comparison between Group 1 and Group 2, Group 1 and Group 3, and Group 2 and Group 3, respectively. We concluded that the image quality of CT pancreatic arteriography, especially for small arteries, can be improved by reconstructing axial images with thinner thickness from the data obtained with submillimetre collimation.


Assuntos
Pâncreas/irrigação sanguínea , Tomografia Computadorizada por Raios X , Adulto , Idoso , Idoso de 80 Anos ou mais , Angiografia/métodos , Angiografia/normas , Artérias , Meios de Contraste , Feminino , Humanos , Processamento de Imagem Assistida por Computador/métodos , Processamento de Imagem Assistida por Computador/normas , Imageamento Tridimensional , Masculino , Pessoa de Meia-Idade , Pâncreas/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Tomografia Computadorizada por Raios X/normas
5.
Water Sci Technol ; 54(6-7): 65-73, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-17120635

RESUMO

Although various numerical methods were used to simulate real floods occurring in cities, the validation of the models was never accurate because of the lack of data about location and event description and about observation for validation. In order to check the capacities of our 2-dimensional shallow water equations model to simulate an urban flood, we then decided to simulate numerically an experimental event with well known characteristics and accurate flow measurements. The physical model presented in (Ishigaki et al, 2003) represents the flooding of the city center of Kyoto in Japan due to an overflow from the Kamo river. The 2-dimensional numerical simulation of this event was then set up and the experimental and computed data were compared. It appears that the event was calculated quite fairly in terms of flow depth and flow rates in the streets and in terms of timing. However, some discrepancies appear between the measurements and the numerical results, mostly due to some topographical local uncertainties and to the capacities of the equations to model the complex flows in the crossroads.


Assuntos
Cidades , Desastres , Modelos Teóricos , Chuva , Movimentos da Água , Simulação por Computador , Japão , Modelos Estruturais , Projetos de Pesquisa
6.
J Phys Chem B ; 110(13): 6804-9, 2006 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-16570988

RESUMO

Well-crystallized iron(III)-doped TiO2 nanopowders with controlled Fe3+ doping concentration and uniform dopant distribution, have been synthesized with plasma oxidative pyrolysis. The photocatalytic reactivity of the synthesized TiO2 nanopowders with a mean particle size of 50-70 nm was quantified in terms of the degradation rates of methyl orange (MO) in aqueous TiO2 suspension under UV (mainly 365 and 316 nm) and visible light irradiation (mainly 405 and 436 nm). The photodecomposition of MO over TiO2 nanopowders followed a distinct two-stage pseudo first order kinetics. Interestingly, the photocatalytic reactivity depends not only on the iron doping concentration but also on the wavelength of the irradiating light. Under UV irradiation, nominally undoped TiO2 had much higher reactivity than Fe3+ -doped TiO2, suggesting that Fe3+ doping (> 0.05 at. %) in TiO2 with a mean particle size of approximately 60 nm was detrimental to the photocatalytic decomposition of methyl orange. Whereas, under visible light irradiation, the Fe3+ -doped TiO2 with an intermediate iron doping concentration of approximately 1 at. % had the highest photocatalytic reactivity due to the narrowing of band gap so that it could effectively absorb the light with longer wavelength. A strategy for improving the photocatalytic reactivity of Fe3+ -doped TiO2 used in the visible light region is also proposed.

7.
Eur Radiol ; 16(3): 726-32, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16284772

RESUMO

PURPOSE: To access the influence of liquid crystal display (LCD) monitors on the detectability of nodular lesions depicted on chest radiographs by comparing them with a high-resolution cathode ray tube (CRT) monitor. MATERIAL AND METHODS: Ten radiologists interpreted 247 soft-copy images on LCD monitors with pixel arrays of 1,024x1,280, 1,200x1,600, 1,536x2,048 and 2,048x2,560, and a CRT monitor with a pixel array of 2,048x2,560, and were asked to indicate their individual confidence levels regarding the presence of a nodule. These images were chest radiographs with and without a lung nodule from the "Standard Digital Image Database" created by the Japanese Society of Radiological Technology. The luminance distributions of all monitors were adjusted to the same, and the ambient illumination was 200 lux. Observer performance was analyzed in terms of the receiver-operating characteristics. RESULTS: No significant statistical differences in nodule detection performance were found among the four LCD monitors and the CRT monitor. CONCLUSION: The nodule detection performance on the LCD monitors with a spatial resolution higher than a matrix size of 1,024x1,280 was found to be equivalent to that on the high-resolution CRT monitor.


Assuntos
Apresentação de Dados , Intensificação de Imagem Radiográfica/instrumentação , Radiografia Torácica , Nódulo Pulmonar Solitário/diagnóstico por imagem , Análise de Variância , Feminino , Humanos , Cristais Líquidos , Masculino , Curva ROC
8.
J Am Chem Soc ; 127(31): 10982-90, 2005 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-16076205

RESUMO

Iron(III)-doped TiO(2) nanopowders, with controlled iron to titanium atomic ratios (R(Fe/Ti)) ranging from nominal 0 to 20%, were synthesized using oxidative pyrolysis of liquid-feed metallorganic precursors in a radiation-frequency (RF) thermal plasma. The valence of iron doped in the TiO(2), phase formation, defect structures, band gaps, and magnetic properties of the resultant nanopowders were systematically investigated using Mössbauer spectroscopy, XRD, Raman spectroscopy, TEM/HRTEM, UV-vis spectroscopy, and measurements of magnetic properties. The iron doped in TiO(2) was trivalent (3+) in a high-spin state as determined by the isomer shift and quadrupole splitting from the Mössbauer spectra. No other phases except anatase and rutile TiO(2) were identified in the resultant nanopowders. Interestingly, thermodynamically metastable anatase predominated in the undoped TiO(2) nanopowders, which can be explained from a kinetic point of view based on classical homogeneous nucleation theory. With iron doping, the formation of rutile was strongly promoted because rutile is more tolerant than anatase to the defects such as oxygen vacancies resulting from the substitution of Fe(3+) for Ti(4+) in TiO(2). The concentration of oxygen vacancies reached a maximum at R(Fe/Ti) = 2% above which excessive oxygen vacancies tended to concentrate. As a result of this concentration, an extended defect like crystallographic shear (CS) structure was established. With iron doping, red shift of the absorption edges occurred in addition to the d-d electron transition of iron in the visible light region. The as-prepared iron-doped TiO(2) nanopowders were paramagnetic in nature at room temperature.

9.
J Neurol Neurosurg Psychiatry ; 75(1): 103-9, 2004 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-14707317

RESUMO

OBJECTIVE: We performed (1)H-MR spectroscopy ((1)H-MRS) on multiple brain regions to determine the metabolite pattern and diagnostic utility of (1)H-MRS in multiple system atrophy (MSA). METHODS: Examining single voxels at 3.0 T, we studied metabolic findings of the putamen, pontine base, and cerebral white matter in 24 MSA patients (predominant cerebellar ataxia (MSA-C), n = 13), parkinsonism (MSA-P), n = 11), in 11 age and duration matched Parkinson's disease patients (PD) and in 18 age matched control subjects. RESULTS: The N-acetylaspartate to creatine ratio (NAA/Cr) in MSA patients showed a significant reduction in the pontine base (p<0.0001) and putamen (p = 0.02) compared with controls. NAA/Cr in cerebral white matter also tended to decline in long standing cases. NAA/Cr reduction in the pontine base was prominent in both MSA-P (p<0.0001) and MSA-C (p<0.0001), and putaminal NAA/Cr reduction was significant in MSA-P (p = 0.009). It was also significant in patients who were in an early phase of their disease, and in those who showed no ataxic symptoms or parkinsonism, or did not show any MRI abnormality of the "hot cross bun" sign or hyperintense putaminal rims. NAA/Cr in MSA-P patients was significantly reduced in the pontine base (p = 0.001) and putamen (p = 0.002) compared with PD patients. The combined (1)H-MRS in the putamen and pontine base served to distinguish patients with MSA-P from PD more clearly. CONCLUSIONS: (1)H-MRS showed widespread neuronal and axonal involvement in MSA. The NAA/Cr reduction in the pontine base proved highly informative in the early diagnosis of MSA prior to MRI changes and even before any clinical manifestation of symptoms.


Assuntos
Ácido Aspártico/análogos & derivados , Ácido Aspártico/metabolismo , Creatina/metabolismo , Espectroscopia de Ressonância Magnética , Atrofia de Múltiplos Sistemas/diagnóstico , Tronco Encefálico/patologia , Tronco Encefálico/fisiologia , Estudos de Casos e Controles , Córtex Cerebral/patologia , Córtex Cerebral/fisiologia , Diagnóstico Diferencial , Feminino , Humanos , Hidrogênio , Masculino , Pessoa de Meia-Idade , Doença de Parkinson/fisiopatologia , Putamen/patologia , Putamen/fisiologia , Valores de Referência
10.
Nucl Med Commun ; 24(10): 1071-80, 2003 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-14508163

RESUMO

This study aimed to determine whether combined examinations of myocardial 2-[18F]fluoro-2-deoxy-D-glucose positron emission tomography (FDG PET) and stress-redistribution 201Tl single-photon emission computed tomography (Tl SPECT) were useful in clarifying myocardial ischaemia and evaluating the prognosis in patients with idiopathic dilated cardiomyopathy (IDCM). Twenty-two patients with IDCM underwent echocardiography, cardiac catheterization, FDG PET, and Tl SPECT. In scintigraphic analysis, the total defect score (TDS) was semiquantitatively determined as the sum of scores of the 17 left ventricular (LV) segments with a 5-point scale (0 as normal to 4 as absent). Patients were classified according to the scintigraphic findings as follows: eight patients with small defects on Tl and FDG (TDS < or = 20) (group I), eight patients with small defects on FDG (TDS < or = 20) with FDG uptake increased relative to Tl or 'mismatch' (group II), and six patients with large defects on FDG and Tl (TDS >20) (group III). Eleven patients (50%) showed reversible defects on Tl and all showed preserved FDG uptake. The patients in group III had significantly lower LV ejection fraction (LVEF) (P<0.05, respectively) and a poorer prognosis as shown by the Kaplan-Meier event-free curve compared with those in groups I and II (P<0.01, respectively). Although patients in group II had significantly greater TDS on Tl compared with those in group I (P<0.01), no significant differences in LVEF and prognosis were found between patients in groups I and II. In multivariate analysis, a TDS on FDG revealed an independent predictor of subsequent cardiac events. In conclusion, such mismatched areas can be assumed to consist of impaired but viable myocardium, and may be associated with ischaemia of the microvasculature. Impaired myocardial glucose metabolism is a more powerful predictor of future cardiac events than perfusion abnormality in patients with IDCM.


Assuntos
Cardiomiopatia Dilatada/diagnóstico por imagem , Fluordesoxiglucose F18 , Aumento da Imagem/métodos , Isquemia Miocárdica/diagnóstico por imagem , Tomografia Computadorizada de Emissão/métodos , Disfunção Ventricular Esquerda/diagnóstico por imagem , Fatores Etários , Cardiomiopatia Dilatada/complicações , Cardiomiopatia Dilatada/diagnóstico , Diagnóstico Diferencial , Intervalo Livre de Doença , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Isquemia Miocárdica/complicações , Isquemia Miocárdica/diagnóstico , Prognóstico , Protetores contra Radiação , Reprodutibilidade dos Testes , Medição de Risco/métodos , Sensibilidade e Especificidade , Fatores Sexuais , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Disfunção Ventricular Esquerda/diagnóstico , Disfunção Ventricular Esquerda/etiologia
11.
Neuroradiology ; 45(9): 626-30, 2003 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12904928

RESUMO

There have been no previous reports on contrast enhancement of the cochlear aqueduct in magnetic resonance imaging. The purpose of the present study was to evaluate the frequency and significance of this finding. Thirty-one patients (15 men and 16 women; age range 18-81 years) with otologic symptoms (sudden sensorineural hearing loss, vertigo, or tinnitus) were examined using contrast-enhanced imaging on a 1.5-T MR scanner. The normal ear served as the control. Two radiologists evaluated contrast enhancement in the area of the cochlear aqueduct. Forty-eight of 62 ears (77.4%) showed contrast enhancement of the cochlear aqueduct, but no significant differences in the frequency of contrast enhancement were observed between patients with and patients without vertigo, tinnitus, sensorineural hearing loss, cerebellopontine angle tumors, or a high-riding jugular bulb. In addition, no gender- or age-related differences were noted. Contrast enhancement of the cochlear aqueduct was frequently observed, but the frequency of enhancement in symptomatic ears was not significantly higher than in control ears. The results of this study may prove helpful in avoiding unnecessary examinations and potential diagnostic confusion.


Assuntos
Aqueduto da Cóclea/patologia , Perda Auditiva Neurossensorial/etiologia , Perda Auditiva Neurossensorial/patologia , Imageamento por Ressonância Magnética/métodos , Zumbido/etiologia , Zumbido/patologia , Vertigem/etiologia , Vertigem/patologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Meios de Contraste/administração & dosagem , Meios de Contraste/farmacocinética , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador
12.
J Digit Imaging ; 14(3): 111-6, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11720332

RESUMO

The authors have developed a new stereoscopic liquid crystal display that provides real-time 3-dimensional image viewing without special eyeglasses. The device consists of 3 major parts: (1) an image display composed of a 10.4-inch color liquid crystal plate with a resolution of 640 x 480, (2) an automatic head tracking system, and (3) a special backlight unit for the right and left eyes. Eight radiologists interpreted 60 cases of magnetic resonance angiography (29 cases of cerebrovascular disease and 31 normal cases) to compare film display and the liquid crystal display (ie, pseudo 3-dimensional display and true 3-dimensional display). Using a continuously distributed scale ranging from 0% to 100%, the observers ranked their confidence levels in determining the presence or absence of steno-occlusive disease, aneurysm, and arteriovenous malformation (AVM) and their locations. For statistical evaluation, receiver operating characteristic (ROC) analysis and Brier score were used. For detecting AVM, film reading showed a significantly higher value in the area under the binormal ROC curve (Az) than did pseudo-3-dimensional display (P < .05). Excluding this, however, no significant difference existed in Az values among the 3 viewing methods. Also, there was no significant difference in Brier score between not only the stereoscopic view and nonstereoscopic view groups, but also the senior and junior groups. Subjective estimation of true 3-dimensional display showed that vessels were more distinguishable with less eye fatigue compared with stereoscopic film reading. The stereoscopic liquid crystal display provided almost equal efficacy to film reading; however, the short optimum distance for observation and the low resolution should be improved.


Assuntos
Transtornos Cerebrovasculares/diagnóstico , Imageamento Tridimensional/instrumentação , Angiografia por Ressonância Magnética/métodos , Apresentação de Dados , Humanos , Processamento de Imagem Assistida por Computador , Imageamento Tridimensional/métodos , Variações Dependentes do Observador , Curva ROC , Fatores de Tempo
13.
Ann Nucl Med ; 15(4): 387-91, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11577767

RESUMO

In patients with cerebral tumors, high accumulations of L-methyl-11C-methionine (11C-Met) have been reported in some cases of cerebral ischemic disease, but no high accumulations of 11C-Met in areas where only transient arterial occlusions are most likely to occur have been reported. Herein we present a case of a high accumulation of 11C-Met in an area of frontal interhemispheric cerebral infarction and a moderately high accumulation with an unclear margin in a distant frontal convexity area. A craniotomy revealed a subacute stage of cerebral infarction in the interhemispheric lesion, and an ischemic change in the distant convexity area. Sixteen months after onset, CT scans demonstrated an infarction area in the interhemispheric lesion only, and no atrophic changes were observed in the distant convexity area indicating that no serious tissue damage had occurred.


Assuntos
Radioisótopos de Carbono , Infarto Cerebral/diagnóstico por imagem , Metionina/análogos & derivados , Compostos Radiofarmacêuticos , Adulto , Infarto Cerebral/diagnóstico , Humanos , Imageamento por Ressonância Magnética , Masculino , Tomografia Computadorizada de Emissão , Tomografia Computadorizada por Raios X
15.
Radiat Med ; 19(4): 185-92, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11550718

RESUMO

PURPOSE: To evaluate contrast-enhanced MR angiography using the 3D time-resolved imaging of contrast kinetics technique (3D-TRICKS) by direct comparison with the fluoroscopic triggered 3D-elliptical centric view ordering (3D-ELLIP) technique. METHODS: 3D-TRICKS and 3D-ELLIP were directly compared on a 1.5-Tesla MR unit using the same spatial resolution and matrix. In 3D-TRICKS, the central part of the k-space is updated more frequently than the peripheral part of the k-space, which is divided in the slice-encoding direction. The carotid arteries were imaged using 3D-TRICKS and 3D-ELLIP sequentially in 14 patients. Temporal resolution was 12 sec for 3D-ELLIP and 6 sec for 3D-TRICKS. The signal-to-noise ratio (S/N) of the common carotid artery was measured, and the quality of MIP images was then scored in terms of venous overlap and blurring of vessel contours. RESULTS: No significant difference in mean S/N was seen between the two methods. Significant venous overlap was not seen in any of the patients examined. Moderate blurring of vessel contours was noted on 3D-TRICKS in five patients and on 3D-ELLIP in four patients. Blurring in the slice-encoding direction was slightly more pronounced in 3D-TRICKS. However, qualitative analysis scores showed no significant differences. CONCLUSION: When the spatial resolution of the two methods was identical, the performance of 3D-TRICKS was found to be comparable in static visualization of the carotid arteries with 3D-ELLIP, although blurring in the slice-encoding direction was slightly more pronounced in 3D-TRICKS. 3D-TRICKS is a more robust technique than 3D-ELLIP, because 3D-ELLIP requires operator-dependent fluoroscopic triggering. Furthermore, 3D-TRICKS can achieve higher temporal resolution. For the spatial resolution employed in this study, 3D-TRICKS may be the method of choice.


Assuntos
Artérias Carótidas/patologia , Meios de Contraste , Imageamento Tridimensional , Angiografia por Ressonância Magnética , Adulto , Idoso , Angiografia Digital , Artérias Carótidas/diagnóstico por imagem , Feminino , Fluoroscopia , Gadolínio DTPA , Humanos , Masculino , Pessoa de Meia-Idade
16.
Methods Inf Med ; 40(3): 259-64, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11501642

RESUMO

We investigated the application of resampling techniques to the statistical analysis of the Brier score (B), and extended them to the statistical comparison of two Bs derived from the same set of patients. The resampling techniques are helpful in the statistical analysis of B, and there are almost no differences between the jackknife method and the bootstrap method in this analysis. Thus, we believe that B should be used more often as an index to evaluate probabilistic judgments in the case in which the data sets for the assessment are "degenerate" as the "receiver operating characteristic data sets."


Assuntos
Técnicas de Apoio para a Decisão , Probabilidade , Estudos de Casos e Controles , Humanos , Neoplasias Pulmonares/diagnóstico por imagem , Curva ROC , Tomografia Computadorizada por Raios X
17.
Semin Musculoskelet Radiol ; 5(2): 167-70, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11500161

RESUMO

There are four types of muscular sarcoidosis: nodular, chronic myopathy, acute myositis, and asymptomatic. The nodular type is important because it may be confused with a soft tissue tumor. Magnetic resonance (MR) imaging provides specific findings. A star-shaped central structure of decreased signal intensity, a "dark star" sign, is seen on the axial images. A long nodule with an inner stripe of decreased signal intensity and outer stripes of increased signal intensity, a "three stripes" sign, is seen on the coronal and sagittal images. In the chronic myopathy type, the role of MR imaging is limited. Gallium scintigraphy, which reflects activity of inflammation, may show increased uptake. In the acute myositis type, MR imaging shows increased signal intensity, and gallium scintigraphy shows increased uptake; however, these findings are nonspecific.


Assuntos
Imageamento por Ressonância Magnética , Doenças Musculares/diagnóstico , Sarcoidose/diagnóstico , Humanos , Músculo Esquelético/patologia , Sarcoidose/classificação
18.
Hepatogastroenterology ; 48(40): 923-7, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11490841

RESUMO

Recent improvements in imaging techniques have made it possible to improve the diagnostic accuracy for detection, staging, and indicating surgical resectability of pancreatic cancer. The latest advance in the computed tomography technique, is the introduction of subsecond multislice helical scanning that improves z-axis resolution in the reformatted images and three-dimensional rendering with a large volume data. Magnetic resonance imaging provides versatile information including magnetic resonance cholangiopancreatography that allows noninvasive delineation of the pancreatic and biliary duct systems. The presence of pancreatic cancer may best be evaluated by dynamic computed tomography or dynamic magnetic resonance imaging with administration of intravenous contrast material. Both computed tomography and magnetic resonance imaging are valuable for the preoperative assessment of local invasion and vascular involvement. Multislice helical computed tomography is currently considered as the best single modality for the diagnosis of pancreatic cancer as it provides excellent image quality. When advanced magnetic resonance imaging equipment is used as a primary modality, in the future, it may have a possibility to replace other imaging modalities.


Assuntos
Adenocarcinoma/diagnóstico , Imageamento por Ressonância Magnética , Neoplasias Pancreáticas/diagnóstico , Tomografia Computadorizada por Raios X , Adenocarcinoma/diagnóstico por imagem , Humanos , Interpretação de Imagem Assistida por Computador , Invasividade Neoplásica , Neoplasias Pancreáticas/diagnóstico por imagem , Neoplasias Pancreáticas/patologia
19.
IEEE Trans Med Imaging ; 20(7): 595-604, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11465466

RESUMO

The purpose of this study is to develop a technique for computer-aided diagnosis (CAD) systems to detect lung nodules in helical X-ray pulmonary computed tomography CT) images. We propose a novel template-matching technique based on a genetic algorithm (GA) template matching (GATM) for detecting nodules existing within the lung area; the GA was used to determine the target position in the observed image efficiently and to select an adequate template image from several reference patterns for quick template matching. In addition, a conventional template matching was employed to detect nodules existing on the lung wall area, lung wall template matching (LWTM), where semicircular models were used as reference patterns; the semicircular models were rotated according to the angle of the target point on the contour of the lung wall. After initial detecting candidates using the two template-matching methods, we extracted a total of 13 feature values and used them to eliminate false-positive findings. Twenty clinical cases involving a total of 557 sectional images were used in this study. 71 nodules out of 98 were correctly detected by our scheme (i.e., a detection rate of about 72%), with the number of false positives at approximately 1.1/sectional image. Our present results show that our scheme can be regarded as a technique for CAD systems to detect nodules in helical CT pulmonary images.


Assuntos
Algoritmos , Neoplasias Pulmonares/diagnóstico por imagem , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Tomografia Computadorizada por Raios X/métodos , Reações Falso-Positivas , Humanos , Neoplasias Pulmonares/genética , Distribuição Normal , Valores de Referência
20.
Cardiovasc Intervent Radiol ; 24(2): 94-8, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11443393

RESUMO

PURPOSE: To evaluate the effect on dilatation of three types of covering materials used for endovascular stent-grafts. METHODS: Stent-grafts with three types of covering material [0.1-mm polytetrafluoroethylene (PTFE), 0.2-mm PTFE, and 0.15-mm woven polyester] were placed in a fluid circuit. For the pulsatile pressure test, the luminal pressure of 190/130 mmHg was loaded up to 300,000 pulses. For the static pressure test, the luminal pressure was increased from 50 to 300 mmHg at 50-mmHg increments. The percent of dilatation of each stent-graft was compared. RESULTS: The 0.1-mm PTFE stent-graft was significantly more dilated than the 0.2-mm PTFE and the 0.15-mm woven polyester stent-graft (p < 0.005) in both examinations. There was no significant difference between the 0.2-mm PTFE and the 0.15-mm woven polyester stent-grafts. The dilatation of the 0.1-mm PTFE stent-graft was irreversible. CONCLUSION: The 0.15-mm woven polyester and the 0.2-mm PTFE stent-grafts may be preferable to the 0.1-mm PTFE stent-graft with regard to dilatation and deformity.


Assuntos
Cateterismo , Fluxo Pulsátil/fisiologia , Stents , Aneurisma Aórtico/terapia , Humanos , Modelos Teóricos , Poliésteres , Politetrafluoretileno , Pulso Arterial
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA