Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 15 de 15
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
J Radiat Res ; 61(4): 616-621, 2020 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-32567660

RESUMO

In patients with various cancers, modified Glasgow prognostic score (mGPS) before treatment has predicted prognoses after antitumor therapy. This study aimed to assess whether pretreatment mGPS also has predictive value in patients with muscle-invasive bladder cancer (MIBC) after radiotherapy. A retrospective review accumulated 98 consecutive MIBC patients treated with definitive 3D-conformal radiotherapy from January 2011 to December 2016 in a single center. It included cT2-4bN0-3M0 patients with a median age of 79 years (range: 49 to 95 years). Radiotherapy was delivered at 60-66 Gy for bladder cancer. Patients were categorized in terms of their pretreatment serum albumin and C-reactive protein (CRP) values as mGPS_0, mGPS_1, and mGPS_2. Among them, cumulative overall survival (OS) rates were compared by Kaplan-Meier plots with log-rank tests. The number of patients with mGPS_0, mGPS_1, and mGPS_2 were 40, 40, and 18, respectively. The median follow-up time for all patients was 19 months (range: 2-73 months). The 2-year OS rate for all patients was 75.7%. The 2-year OS rates for mGPS_0, mGPS_1, and mGPS_2 were 85.1%, 71.3%, and 60.9%, respectively. Kaplan-Meier curves revealed a significantly higher cumulative OS rate for mGPS_0 compared with mGPS_1 and mGPS_2 (P = 0.003). Using multivariate Cox regression analysis, mGPS_0 and good performance status were associated with favorable OS rates, of which mGPS_0 was more significant (Hazard ratio 2.74, 95% CI 1.30-5.57, P = 0.008). Modified Glasgow prognostic score may be a novel biomarker that can predict survival in patients with MIBC after radiotherapy.


Assuntos
Neoplasias Musculares/diagnóstico , Neoplasias Musculares/secundário , Neoplasias da Bexiga Urinária/diagnóstico , Neoplasias da Bexiga Urinária/mortalidade , Neoplasias da Bexiga Urinária/radioterapia , Idoso , Idoso de 80 Anos ou mais , Proteína C-Reativa/metabolismo , Feminino , Seguimentos , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Neoplasias Musculares/mortalidade , Neoplasias Musculares/radioterapia , Prognóstico , Radioterapia/métodos , Estudos Retrospectivos , Índice de Gravidade de Doença , Resultado do Tratamento
2.
Anticancer Res ; 38(8): 4827-4831, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30061255

RESUMO

BACKGROUND/AIM: Secure dose escalation is required to compensate avoidance of concurrent chemotherapy in radiotherapy for increasing elderly bladder cancer. We aimed to evaluate the efficacy of lipiodol submucosally injected as a fiducial marker during image-guided radiotherapy (Lip-IGRT) for muscle invasive bladder cancer (BC). PATIENTS AND METHODS: Twenty-three patients with T2a-4aN0-1M0 BC underwent whole-bladder irradiation of 46 Gy and Lip-IGRT of 20 Gy, conventionally. The bladder volume exposed to 19 Gy (bV19:%) on Lip-IGRT was referred as an index predicting cystitis. RESULTS: Lipiodol consistently highlighted the boundaries of 20 tumors (88%) on planning and portal verification images. Three of 4 patients under oral anticoagulant agents usage were complicated with grade ≥2 hematuria for 3 days (a patient with a bV19 of >50%) or more than a year (2 patients with bV19 of <50%) after the injection. The 3-year overall survival and disease-free survival rates were 70.4% and 71.1%, respectively. CONCLUSION: Lipiodol marking is an effective way of demarcating BC. However, it is necessary to address the comorbidities of elderly patients.


Assuntos
Óleo Etiodado/administração & dosagem , Marcadores Fiduciais , Radioterapia Guiada por Imagem/métodos , Neoplasias da Bexiga Urinária/radioterapia , Idoso , Idoso de 80 Anos ou mais , Envelhecimento , Comorbidade , Intervalo Livre de Doença , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Musculares/secundário , Estudos Prospectivos , Bexiga Urinária/patologia , Neoplasias da Bexiga Urinária/patologia
3.
Anticancer Res ; 35(11): 6231-7, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26504056

RESUMO

BACKGROUND/AIM: The aim of the present study was to assess clinical outcomes of postoperative radiotherapy for biliary tract cancer patients. PATIENTS AND METHODS: Clinical results of 187 patients treated with external irradiation in 31 Japanese Institutions between 2000 and 2011 were retrospectively analyzed. The median radiation dose was 50.4 Gy in fractions of 1.8-2 Gy. RESULTS: Two-year actuarial overall survival and locoregional control (LCs) rates were 56% and 68%, respectively. In multivariate analysis, macroscopic residual tumor (R2) and irradiated doses <54 Gy were significant indicators of poor LC prognosis. For patients with complete resection (R0) or microscopic residual tumor (R1), 2-year LCs were 71% for <54 Gy and 83% for ≥54 Gy; doses ≥54 Gy were associated with high long-term LCs. There was no significant difference in acute adverse event rates between <54 Gy and ≥54 Gy. CONCLUSION: Postoperative irradiation doses of approximately 54 Gy are safe and effective for R0 or R1 resection patients.


Assuntos
Adenocarcinoma/radioterapia , Neoplasias do Sistema Biliar/radioterapia , Carcinoma de Células Escamosas/radioterapia , Recidiva Local de Neoplasia/radioterapia , Neoplasia Residual/radioterapia , Adenocarcinoma/mortalidade , Adenocarcinoma/patologia , Adenocarcinoma/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias do Sistema Biliar/mortalidade , Neoplasias do Sistema Biliar/patologia , Neoplasias do Sistema Biliar/cirurgia , Carcinoma de Células Escamosas/mortalidade , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/cirurgia , Terapia Combinada , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/mortalidade , Recidiva Local de Neoplasia/patologia , Recidiva Local de Neoplasia/cirurgia , Estadiamento de Neoplasias , Neoplasia Residual/mortalidade , Neoplasia Residual/patologia , Neoplasia Residual/cirurgia , Período Pós-Operatório , Prognóstico , Dosagem Radioterapêutica , Radioterapia Adjuvante , Estudos Retrospectivos , Taxa de Sobrevida
4.
Appl Radiat Isot ; 103: 25-30, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26046520

RESUMO

To measure X-ray spectra with high count rates, we developed a detector consisting of a Lu2(SiO4)O [LSO] crystal with a decay time of 40 ns and a multipixel photon counter (MPPC). The photocurrents flowing through the MPPC are converted into voltages and amplified by a high-speed current-voltage amplifier, and event pulses from the amplifier are sent to a multichannel analyzer to measure spectra. We used three MPPCs of 100, 400 and 1600 pixels/mm(2), and the MPPCs were driven under pre-Geiger mode at a temperature of 20 °C. At a tube voltage of 100 kV and a tube current of 5.0 µA, the maximum count rate was 12.8 kilo-counts per second. The event-pulse widths were 200 ns, and the energy resolution was 53% at 59.5 keV using a 100-pixel MPPC.


Assuntos
Amplificadores Eletrônicos , Lutécio/efeitos da radiação , Fotometria/instrumentação , Radiometria/instrumentação , Processamento de Sinais Assistido por Computador/instrumentação , Raios X , Desenho de Equipamento , Análise de Falha de Equipamento , Fótons , Doses de Radiação , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Dióxido de Silício/efeitos da radiação , Transdutores
5.
Int J Radiat Oncol Biol Phys ; 89(4): 822-9, 2014 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-24969796

RESUMO

PURPOSE: To determine whether adding intraluminal brachytherapy (ILBT) to definitive radiation therapy (RT) for unresectable biliary tract cancer has a positive impact on survival outcome. METHODS AND MATERIALS: The original cohort comprised 209 patients, including 153 who underwent external beam RT (EBRT) alone and 56 who received both ILBT and EBRT. By matching propensity scores, 56 pairs (112 patients) consisting of 1 patient with and 1 patient without ILBT were selected. They were well balanced in terms of sex, age, performance status, clinical stage, jaundice, and addition of chemotherapy. The impact of ILBT on overall survival (OS), disease-specific survival (DSS), and local control (LC) was investigated. RESULTS: The 2-year OS rates were 31% for the ILBT+ group and 40% for theILBT- group (P=.862). The 2-year DSS rates were 42% for the ILBT+ group and 41% for the ILBT- group (P=.288). The 2-year LC rates were 65% for the ILBT+ group and 35% for the ILBT- group (P=.094). Three of the 4 sensitivity analyses showed a significantly better LC for the ILBT+ group (P=.010, .025, .049), and another showed a marginally better LC (P=.068), and none of the sensitivity analyses showed any statistically significant differences in OS or DSS. CONCLUSIONS: In the treatment for unresectable biliary tract cancer, the addition of ILBT to RT has no impact on OS or DSS but is associated with better LC. Therefore, the role of ILBT should be addressed by other measures than survival benefit, for example, by less toxicity, prolonged biliary tract patency decreasing the need for further palliative interventions, or patient quality of life.


Assuntos
Neoplasias do Sistema Biliar/mortalidade , Neoplasias do Sistema Biliar/radioterapia , Braquiterapia/mortalidade , Braquiterapia/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Análise de Variância , Bases de Dados Factuais , Intervalo Livre de Doença , Feminino , Humanos , Japão , Masculino , Análise por Pareamento , Pessoa de Meia-Idade , Pontuação de Propensão , Estudos Retrospectivos , Taxa de Sobrevida , Resultado do Tratamento
6.
Radiother Oncol ; 110(3): 546-52, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24560766

RESUMO

PURPOSE: To seek for the possible factors influencing overall survival (OS) with radiotherapy (RT) for biliary tract cancer. MATERIALS AND METHODS: Data were collected retrospectively from RT database of 31 institutions in Japan. All patients underwent at least external beam RT. The factors influencing OS were investigated. RESULTS: Data of 498 patients were analyzed. Median OS of the 212 patients who underwent surgery was significantly better than that of the 286 patients without surgery (31 vs. 15 months, p<0.001). The OS for the R0 or R1 resection group was significantly longer than that for the R2 or non-surgery group, as well as for n0 compared to n1 (all p<0.001). Chemoradiotherapy (CRT), both sequential and concurrent, resulted in a better OS than RT alone for the n1 group (31 vs. 13 months, p<0.001), and marginally better for the R0/R1 group (p=0.065; p=0.054 for concurrent CRT). However, no such benefit was observed for the R2/non-surgical patients. Multivariate analysis identified performance status, clinical stage, and surgery as significant factors. CONCLUSION: Surgery, especially R0/R1 resection, seemed as the gold standard for treatment of biliary tract cancer including RT, even in the highly heterogeneous population obtained from the multicenter retrospective study. The possibility was shown that CRT yielded better survival benefit especially for n1 patients. We recommend that future prospective trials include an arm of adjuvant CRT at least for n1 and possibly R0/R1 patients.


Assuntos
Neoplasias do Sistema Biliar/radioterapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias do Sistema Biliar/mortalidade , Quimiorradioterapia , Feminino , Humanos , Japão , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
7.
Radiother Oncol ; 107(2): 159-64, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23541641

RESUMO

BACKGROUND AND PURPOSE: To determine the dose constraints for rectal bleeding in brachytherapy (BRT) combined with external beam radiotherapy (EBRT). MATERIALS AND METHODS: Post-BRT, pelvic computed tomography images were used for subsequent EBRT planning and BRT postplans in 37 patients. The physical doses for each plan were converted to biologically effective doses, and corresponding voxel doses were integrated to plot the summed dose-volume histogram (sum-DVH). Between 5 patients with (bled-pts) and 32 without (spared-pts) grade 2 or 3 rectal bleeding, the differences in the mean minimal dose (rDn) covering the rectal volume of 0.5-10.0 cc and the rectal volume (rVn) receiving the calculated dose of 20-150Gy were compared. RESULTS: The differences in the summed-rDn were determined by BRT exposure, while those of the summed-rVn were determined in the low-dose range and superimposed in the high-dose range by EBRT exposure. Of the 13 patients with rV150 of >1.2 cc, 4 were bled-pts (30.8%). Of the 24 patients with rV150 of ≤ 1.2cc, 1 was a bled-pts (4.2%) (p=0.024; odds ratio, 10.2; CI (95%), 1.0-104.3). CONCLUSIONS: The mono-scale DVH analysis is a promising method for exploring the threshold for rectal bleeding in combined radiotherapy.


Assuntos
Braquiterapia , Neoplasias da Próstata/radioterapia , Reto/efeitos da radiação , Adulto , Idoso , Hemorragia Gastrointestinal/etiologia , Humanos , Masculino , Pessoa de Meia-Idade , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador
8.
Radiat Oncol ; 8: 76, 2013 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-23547715

RESUMO

BACKGROUND: The patterns of radiotherapy (RT) practice for biliary tract cancer (BTC) in Japan are not clearly established. METHODS: A questionnaire-based national survey of RT used for BTC treatment between 2000 and 2011 was conducted by the Japanese Radiation Oncology Study Group. Detailed information was collected for 555 patients from 31 radiation oncology institutions. RESULTS: The median age of the patients was 69 years old (range, 33-90) and 81% had a good performance status (0-1). Regarding RT treatment, 78% of the patients were treated with external beam RT (EBRT) alone, 17% received intraluminal brachytherapy, and 5% were treated with intraoperative RT. There was no significant difference in the choice of treatment modality among the BTC subsites. Many patients with EBRT were treated with a total dose of 50 or 50.4 Gy (~40%) and only 13% received a total dose ≥60 Gy, even though most institutions (90%) were using CT-based treatment planning. The treatment field consisted of the primary tumor (bed) only in 75% of the patients. Chemotherapy was used for 260 patients (47%) and was most often administered during RT (64%, 167/260), followed by after RT (63%, 163/260). Gemcitabine was the most frequently used drug for chemotherapy. CONCLUSIONS: This study established the general patterns of RT practice for BTC in Japan. Further surveys and comparisons with results from other countries are needed for development and optimization of RT for patients with BTC in Japan.


Assuntos
Neoplasias do Sistema Biliar/radioterapia , Padrões de Prática Médica/estatística & dados numéricos , Radioterapia (Especialidade)/estatística & dados numéricos , Radioterapia/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Japão , Masculino , Pessoa de Meia-Idade , Padrões de Prática Médica/normas , Radioterapia (Especialidade)/normas , Inquéritos e Questionários
9.
Brachytherapy ; 10(3): 208-13, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-20685175

RESUMO

PURPOSE: To elucidate the potential effects of prostate deformation on dose distribution during Iodine-125 ((125)I) seed implantation brachytherapy for prostate cancer. METHODS AND MATERIALS: A retrospective analysis of 245 patients who underwent only transperineal brachytherapy for low-risk prostate adenocarcinoma was performed. The maximum diameters of the prostate were measured before treatment by transrectal ultrasound volumetry along right to left (RL), anterior to posterior (AP), and apex to base (Length) directions. The seeds were inserted by the modified peripheral loading method using real-time ultrasound-guided seed placement. The ellipsoid deformation rates in the axial plane (E(ax)) and in the sagittal plane (E(sag)) were defined as [RL-AP]/RL and [Length-AP]/Length, respectively. The correlation between them and the dose-volume histogram parameters at 30 days after the operation was evaluated. A simulation test was additionally performed to ascertain the change in dose distribution among virtual volumes built in a radiotherapy planning device that corresponds to prostates with increased Eax or Esag. RESULTS: The mean Esag and Eax of patients were 0.313 (range, -0.28 to 0.844) and 0.261 (range, -0.02 to 0.54), respectively. Esag showed a positive correlation with dose (Gy) covering 90% of the prostate volume (pD(90)), prostate volume (%) covered by 100% of the prescribed dose (pV(100)), the rectal volume (cc) irradiated by 100% of the prescribed dose (rV(100)), and the rectal volume (cc) irradiated by 150% of the prescribed dose (rV(150)), whereas Eax showed a positive correlation with prostate volume (%) covered by 150% of the prescribed dose (pV(150)) and the urethral dose (Gy) delivered to 5% of its volume (uD(5)). The simulation test suggested that the prescribed dose resulted in the best coverage in patients with increased E(sag), and that patients with increased E(ax) exhibited poor urethral sparing from overdosage. CONCLUSION: In the seed implantation method, ellipsoid deformation of the prostate causes higher rectal dose exposure or dose delivery to the urethra.


Assuntos
Braquiterapia/métodos , Próstata/diagnóstico por imagem , Próstata/efeitos da radiação , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/radioterapia , Radiometria , Idoso , Idoso de 80 Anos ou mais , Humanos , Masculino , Pessoa de Meia-Idade , Tamanho do Órgão , Dosagem Radioterapêutica , Resultado do Tratamento , Ultrassonografia
10.
Brachytherapy ; 9(1): 71-5, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-19880354

RESUMO

PURPOSE: To establish a method of quantitative assessment of the duodenal exposure dose to avoid duodenal morbidity after radiotherapy for bile duct cancer. METHODS AND MATERIALS: After external beam radiotherapy (ERTx) and intraluminal high-dose-rate brachytherapy (BRTx), 4 of 10 patients developed Grade 3 or 4 ulcers at the posterior wall of the duodenal bulb (PWDB) (compromised group); the remainder exhibited no duodenal complications (spared group) for 14 (range, 7-59) months after radiotherapy. The radiation exposure to the duodenal volume at risk (V(duod)) in ERTx and BRTx was individually analyzed using dose-volume histograms in terms of the mean doses (the average dose of V(duod)[D(ave)] and the median dose of V(duod) [D(median)]), dose covering 1% or 5% of V(duod) (dose covering 1% of the V(duod) [D(1)] and dose covering 5% of the V(duod) [D(5)], respectively), and the V(duod) receiving 100% or 150% of the prescribed radiation dose (V(100) and V(150), respectively) in ERTx (D(ave), D(median), D(5)) and BRTx (D(ave), D(1), D(5), V(100), V(150)). D(ave) and D(5) were converted to biologically effective doses (BEDs), and each corresponding values of ERTx and BRTx were summed presenting as BED(ave_sum) and BED(5_sum). RESULTS: The PWDB was consistently involved in 100% of the prescription dose area in ERTx. The compromised group had smaller exposure doses without significant difference (SD). In BRTx, the PWDB was exposed to higher doses. The compromised group had larger dose exposures without SD and larger volume exposures (V(100), V(150)) with SD in BRTx. The BED(ave_sum) and BED(5_sum) showed no difference between the groups. CONCLUSIONS: Measuring the duodenal volume exposed to determine doses that exceed the prescription in BRTx may be useful for predicting intractable complications in the combined radiotherapy.


Assuntos
Adenocarcinoma/radioterapia , Neoplasias dos Ductos Biliares/radioterapia , Duodenopatias/diagnóstico , Duodenopatias/etiologia , Lesões por Radiação/diagnóstico , Lesões por Radiação/etiologia , Adenocarcinoma/complicações , Idoso , Idoso de 80 Anos ou mais , Neoplasias dos Ductos Biliares/complicações , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Dosagem Radioterapêutica , Medição de Risco , Resultado do Tratamento
11.
Int J Radiat Oncol Biol Phys ; 75(2): 338-42, 2009 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-19735860

RESUMO

PURPOSE: To confirm the advantage of chemoradiotherapy using intra-arterial docetaxel with intravenous cisplatin and 5-fluorouracil. PATIENTS AND METHODS: A total of 26 oropharyngeal cancer patients (1, 2, 2, and 21 patients had Stage I, II, III, and IVa-IVc, respectively) were treated with two sessions of this chemoradiotherapy regimen. External beam radiotherapy was delivered using large portals that included the primary site and the regional lymph nodes initially (range, 40-41.4 Gy) and the metastatic lymph nodes later (60 or 72 Gy). All tumor-supplying branches of the carotid arteries were cannulated, and 40 mg/m(2) docetaxel was individually infused on Day 1. The other systemic chemotherapy agents included 60 mg/m(2) cisplatin on Day 2 and 500 mg/m(2) 5-fluorouracil on Days 2-6. RESULTS: The primary response of the tumor was complete in 21 (81%), partial in 4 (15%), and progressive in 1 patient. Grade 4 mucositis, leukopenia, and dermatitis was observed in 3, 2, and 1 patients, respectively. During a median follow-up of 10 months, the disease recurred at the primary site and at a distant organ in 2 (8%) and 3 (12%) patients, respectively. Three patients died because of cancer progression. Two patients (8%) with a partial response were compromised by lethal bleeding from the tumor bed or chemotherapeutic toxicity. The 3-year locoregional control rate and the 3-year overall survival rate was 73% and 77%, respectively. CONCLUSION: This method resulted in an excellent primary tumor response rate (96%) and moderate acute toxicity. Additional follow-up is required to ascertain the usefulness of this modality.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Carcinoma de Células Escamosas/tratamento farmacológico , Carcinoma de Células Escamosas/radioterapia , Neoplasias Orofaríngeas/tratamento farmacológico , Neoplasias Orofaríngeas/radioterapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Carcinoma de Células Escamosas/irrigação sanguínea , Cisplatino/administração & dosagem , Terapia Combinada/métodos , Docetaxel , Esquema de Medicação , Feminino , Fluoruracila/administração & dosagem , Seguimentos , Humanos , Infusões Intra-Arteriais/métodos , Leucopenia/etiologia , Masculino , Pessoa de Meia-Idade , Mucosite/etiologia , Neoplasias Orofaríngeas/irrigação sanguínea , Radiodermite/etiologia , Dosagem Radioterapêutica , Indução de Remissão , Taxoides
12.
Neuroradiology ; 46(10): 817-21, 2004 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15316699

RESUMO

To elucidate MR imaging changes of the substantia innominata in Parkinson's disease (PD), using a 1.5-T superconductive MR unit, the thickness of the substantia innominata was measured on coronal thin-section images in 44 PD patients and 20 age-matched control subjects. We also evaluated the correlation between the thickness of the substantia innominata and mental status in PD patients. Mean thickness of the substantia innominata was 2.3 mm in PD patients, and 2.5 mm in control subjects. Thinning of the substantia innominata was statistically significant in PD patients compared with control subjects, although there were large overlaps. Among the PD patients, thinning was remarkable in cases with dementia. A positive correlation between thickness of substantia innominata and score of Mini-Mental-Status-Examination was also observed in PD patients. Atrophy of the substantia innominata was demonstrated, especially in PD patients with cognitive impairment, on coronal MR images, and this is compatible with the previous pathological reports.


Assuntos
Doença de Parkinson/patologia , Substância Inominada/patologia , Adulto , Idoso , Estudos de Casos e Controles , Transtornos Cognitivos/etiologia , Transtornos Cognitivos/patologia , Demência/etiologia , Demência/patologia , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Doença de Parkinson/psicologia , Estudos Prospectivos , Testes Psicológicos , Índice de Gravidade de Doença
13.
Magn Reson Med Sci ; 2(3): 133-9, 2003 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-16222104

RESUMO

Introduction of clinical high-field MRI has raised interest in the use of clinical imaging--the efficacy of which has not yet been fully established--in daily practice. A high signal-to-noise ratio and profound susceptibility effects can improve the spatial resolution and image contrast of clinical imaging, whereas the heating effects of the radio frequency tend to prolong acquisition time. As well, inhomogeneities in the static or local magnetic fields can have a negative effect on image quality. The T(1) prolongation may affect T(1) contrast yet improve the enhancement effect of gadolinium chelate and the inflow effect of MR angiography. High-contrast imaging, such as the short inversion-time inversion recovery technique, can provide excellent intra- and extracerebral contrast comparable to microscopic or macroscopic specimens. High-field systems can also be applied to microscopic imaging. High-field MRI is expected to have an increased clinical impact in the near future. Technological advances tailored to high-field systems, as well as the accumulation of scientific evidence, will be necessary to establish its predominance over conventional MRI.


Assuntos
Doenças do Sistema Nervoso Central/diagnóstico , Sistema Nervoso Central/patologia , Imageamento por Ressonância Magnética/métodos , Meios de Contraste , Humanos , Microscopia
14.
AJNR Am J Neuroradiol ; 23(10): 1747-56, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12427635

RESUMO

BACKGROUND AND PURPOSE: A reduction in the area of the substantia nigra (SN) has been shown in patients with Parkinson disease. The substantia nigra is anteroinferolateral to the red nucleus, and it is important to precisely locate its true anatomic location to accurately measure SN area. Our purpose was to determine the exact location of the substantia nigra by correlating imaging and anatomic findings. We also attempted to quantitate SN area in patients with Parkinson disease compared with that in healthy control subjects on the basis of proton density-weighted spin-echo (SE) and fast short inversion time inversion-recovery (STIR) MR imaging findings. METHODS: In four healthy volunteers, dual-echo SE and fast STIR MR images were obtained in three orthogonal planes and an oblique coronal plane. These images were correlated with anatomic specimens to determine the location of the SN. The area of the SN was also measured on oblique coronal fast STIR images obtained at a plane perpendicular to the SN in 22 patients with Parkinson disease and in 22 age- and sex-matched healthy volunteers. RESULTS: The true anatomic location of the SN, anteroinferolateral to the red nucleus, was accurately identified, not on T2-weighted images, but on proton density-weighted SE images and fast STIR images as an area of hyperintense gray matter. The hypointense area seen on T2-weighted images corresponded to the anterosuperior aspect of the SN and to the adjacent crus cerebri. No statistically significant differences were noted in the size of the SN when the oblique coronal images of patients with Parkinson disease were compared with those of the control groups. CONCLUSION: The SN is located mainly beneath the red nucleus. Its location cannot be determined on the basis of T2-weighted imaging results but rather on the basis of proton density-weighted SE or fast STIR findings. SN volume loss is not found in Parkinson disease, and this finding is compatible with that of recent pathology reports in the literature.


Assuntos
Encéfalo/patologia , Doença de Parkinson/diagnóstico , Adulto , Idoso , Anatomia Transversal , Encéfalo/diagnóstico por imagem , Imagem de Difusão por Ressonância Magnética , Imagem Ecoplanar , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prótons , Radiografia , Substância Negra/diagnóstico por imagem , Substância Negra/patologia
15.
Magn Reson Med Sci ; 1(1): 1-6, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-16037661

RESUMO

We established an easy-to-use technique for performing contrast-enhanced carotid MR angiography (MRA) with a commercial scanner. Twenty-three patients with suspected carotid or vertebral arterial lesions were prospectively studied. Two techniques were applied in the study. After performing sagittal time-resolved acquisitions, we undertook a coronal single-phase 3D acquisition, in which the injection timing was estimated from the preceding images. In each case, we obtained multidirectional images with sufficient venous suppression. The combined use of time-resolved and single-phase 3D MRA is a feasible technique for obtaining selective arterial images without the use of special applications or hardware.


Assuntos
Estenose das Carótidas/diagnóstico , Angiografia por Ressonância Magnética/métodos , Idoso , Idoso de 80 Anos ou mais , Meios de Contraste , Feminino , Gadolínio DTPA , Humanos , Imageamento Tridimensional , Masculino , Pessoa de Meia-Idade , Artéria Vertebral
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...