992 resultados para hyperpolarized, xenon, Polarizer, GE180, T1 xenon


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Purpose: Cervical foraminal injection performed with a direct foraminal approach may induce serious neurologic complications. We describe a technique of CT-guided cervical facet joint (CFJ) injection as an indirect foraminal injection, including feasibility and diffusion pathways of the contrast agent. Methods and materials: Retrospective study included 84 punctures in 65 consecutive patients presenting neck pain and/or radiculopathy related to osteoarthritis or soft disc herniation. CT images were obtained from C2 to T1 in supine position, with a metallic landmark on the skin. CFJ punctures were performed by MSK senior radiologists with a lateral approach. CT control of the CFJ opacification was performed after injections of contrast agent (1 ml), followed by slow-acting corticosteroid (25 mg). CFJ opacification was considered as successful when joint space and/or capsular recess opacification occurred. The diffusion of contrast agent in foraminal and epidural spaces was recorded. We assessed the epidural diffusion both on axial and sagittal images, with a classification in two groups (small diffusion or large diffusion). Results: CFJ opacification was successful in 82% (69/84). An epidural and/or foraminal opacification was obtained in 74% (51/69). A foraminal opacification occurred in 92% (47/51) and an epidural opacification in 63% (32/51), with small diffusion in 47% (15/32) and large diffusion in 53% (17/32). No complication occurred. Conclusion: CT- guided CFJ injection is easy to perform and safe. It is most often successful, with a frequent epidural and/or foraminal diffusion of the contrast agent. This technique could be an interesting and safe alternative to foraminal cervical injection.

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OBJECTIVES: To assess the accuracy of high-resolution (HR) magnetic resonance imaging (MRI) in diagnosing early-stage optic nerve (ON) invasion in a retinoblastoma cohort. METHODS: This IRB-approved, prospective multicenter study included 95 patients (55 boys, 40 girls; mean age, 29 months). 1.5-T MRI was performed using surface coils before enucleation, including spin-echo unenhanced and contrast-enhanced (CE) T1-weighted sequences (slice thickness, 2 mm; pixel size <0.3&#8201;Ã&#8201;0.3 mm(2)). Images were read by five neuroradiologists blinded to histopathologic findings. ROC curves were constructed with AUC assessment using a bootstrap method. RESULTS: Histopathology identified 41 eyes without ON invasion and 25 with prelaminar, 18 with intralaminar and 12 with postlaminar invasion. All but one were postoperatively classified as stage I by the International Retinoblastoma Staging System. The accuracy of CE-T1 sequences in identifying ON invasion was limited (AUC&#8201;=&#8201;0.64; 95 % CI, 0.55&#8201;-&#8201;0.72) and not confirmed for postlaminar invasion diagnosis (AUC&#8201;=&#8201;0.64; 95 % CI, 0.47&#8201;-&#8201;0.82); high specificities (range, 0.64&#8201;-&#8201;1) and negative predictive values (range, 0.81&#8201;-&#8201;0.97) were confirmed. CONCLUSION: HR-MRI with surface coils is recommended to appropriately select retinoblastoma patients eligible for primary enucleation without the risk of IRSS stage II but cannot substitute for pathology in differentiating the first degrees of ON invasion. KEY POINTS: ⢠HR-MRI excludes advanced optic nerve invasion with high negative predictive value. ⢠HR-MRI accurately selects patients eligible for primary enucleation. ⢠Diagnosis of early stages of optic nerve invasion still relies on pathology. ⢠Several physiological MR patterns may mimic optic nerve invasion.

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Trilateral retinoblastoma (TRb) is a rare disease associating intraocular retinoblastoma with intracranial primitive neuroectodermal tumor. Treatment is difficult and prognosis is poor. This multicenter study evaluates clinical findings and MR imaging characteristics of associated intracranial tumors in Rb patients. Clinical data of 17 patients (16 TRb and 1 quadrilateral Rb patients) included time intervals between Rb and TRb diagnosis and presence of baseline brain-imaging (BBI). Two reviewers reviewed all images individually and one reviewer per center evaluated their images. Consensus was reached during a joint scoring session. Studies were reviewed for tumor location, size and imaging characteristics (signal intensity (SI) on T1- and T2-weighted images, enhancement pattern and cystic appearance). Of 18 intracranial tumors, 78 % were located in the pineal gland and 22 % suprasellar. All tumors showed well-defined borders with mostly heterogenous enhancement (72 %) and isointense SI on T1- (78 %) and T2-weighted images (72 %) compared to gray matter. The majority of pineal TRbs showed a cystic component (57 %). TRb detected synchronously with the intraocular tumors on BBI (n = 7) were significantly smaller (P = 0.02), and mainly asymptomatic than TRb detected later on (n = 10). Overall, 5-year-survival of TRb patients detected on BBI was 67 % (95 % CI 29-100 %) compared to 11 % (95 % CI 0-32 %) for the group with delayed diagnosis. TRb mainly develops in the pineal gland and frequently presents with a cystic appearance that could be misinterpreted as benign pineal cysts. Routine BBI in all newly diagnosed Rb patients can detect TRb at a subclinical stage.

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Foram comparados três níveis de proteína, com leitões desmamados aos 29 dias de idade, no período de 0 a 15 dias após o desmame. Os tratamentos foram os seguintes: T1- dieta testemunha, com 20% de proteína bruta (PB); T2 - dieta com 18% PB; T3 - dieta com 16% PB. As dietas eram isolisínicas com 1,15% de lisina. Durante a fase de aleitamento foi fornecida uma dieta pré-inicial a todos os leitões, a partir do sétimo dia de vida. De 16 a 36 dias após o desmame, foi fornecida uma dieta com 18% de PB a todos os leitões. A redução do nível de PB da dieta para 18% ou 16% não afetou (P>0,10) o desempenho dos leitões em nenhum dos períodos estudados e reduziu (P<0,01) a incidência e severidade da diarréia. Concluiu-se que a redução do nível de PB e da proporção do farelo de soja na dieta de leitões desmamados aos 29 dias de idade, acompanhada de suplementação com lisina, por 15 dias após o desmame, pode proporcionar redução na incidência e severidade da diarréia, sem afetar o desempenho.

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BACKGROUND: Studies on hexaminolevulinate (HAL) cystoscopy report improved detection of bladder tumours. However, recent meta-analyses report conflicting effects on recurrence. OBJECTIVE: To assess available clinical data for blue light (BL) HAL cystoscopy on the detection of Ta/T1 and carcinoma in situ (CIS) tumours, and on tumour recurrence. DESIGN, SETTING, AND PARTICIPANTS: This meta-analysis reviewed raw data from prospective studies on 1345 patients with known or suspected non-muscle-invasive bladder cancer (NMIBC). INTERVENTION: A single application of HAL cystoscopy was used as an adjunct to white light (WL) cystoscopy. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: We studied the detection of NMIBC (intention to treat [ITT]: n=831; six studies) and recurrence (per protocol: n=634; three studies) up to 1 yr. DerSimonian and Laird's random-effects model was used to obtain pooled relative risks (RRs) and associated 95% confidence intervals (CIs) for outcomes for detection. RESULTS AND LIMITATIONS: BL cystoscopy detected significantly more Ta tumours (14.7%; p&lt;0.001; odds ratio [OR]: 4.898; 95% CI, 1.937-12.390) and CIS lesions (40.8%; p&lt;0.001; OR: 12.372; 95% CI, 6.343-24.133) than WL. There were 24.9% patients with at least one additional Ta/T1 tumour seen with BL (p&lt;0.001), significant also in patients with primary (20.7%; p&lt;0.001) and recurrent cancer (27.7%; p&lt;0.001), and in patients at high risk (27.0%; p&lt;0.001) and intermediate risk (35.7%; p=0.004). In 26.7% of patients, CIS was detected only by BL (p&lt;0.001) and was also significant in patients with primary (28.0%; p&lt;0.001) and recurrent cancer (25.0%; p&lt;0.001). Recurrence rates up to 12 mo were significantly lower overall with BL, 34.5% versus 45.4% (p=0.006; RR: 0.761 [0.627-0.924]), and lower in patients with T1 or CIS (p=0.052; RR: 0.696 [0.482-1.003]), Ta (p=0.040; RR: 0.804 [0.653-0.991]), and in high-risk (p=0.050) and low-risk (p=0.029) subgroups. Some subgroups had too few patients to allow statistically meaningful analysis. Heterogeneity was minimised by the statistical analysis method used. CONCLUSIONS: This meta-analysis confirms that HAL BL cystoscopy significantly improves the detection of bladder tumours leading to a reduction of recurrence at 9-12 mo. The benefit is independent of the level of risk and is evident in patients with Ta, T1, CIS, primary, and recurrent cancer.

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O objetivo deste trabalho foi comparar a economicidade de algumas técnicas de recuperação de pastagens, ao longo de um período, avaliando o desempenho animal sob pastejo rotacionado. As atividades foram desenvolvidas em Brasilândia, MS, em seis módulos de cinco hectares cada. Os módulos T1 (milho + Brachiaria brizantha), T2 (arroz + B. brizantha) e T3 (arroz + B. brizantha + Calopogonium mucunoides) foram renovados de acordo com a técnica preconizada pelo Sistema Barreirão. O módulo T4 foi formado de acordo com método convencional da região com B. brizantha. Os módulos T5 e T6 foram selecionados nas proximidades dos demais módulos como testemunhas, predominando a B. humidicola no módulo T5 e B. humidicola e B. decumbens no módulo T6. A avaliação econômica foi baseada na produção de grãos, ganho de peso e na lotação animal. Os resultados encontrados nos sistemas analisados, nos módulos T1, T2, T3 e T4 demonstram que a exploração da pecuária bovina de corte, no pasto recuperado, é uma atividade economicamente lucrativa, e que os módulos T1, T2 e T3 apresentam vantagem comparativa, devido à produção de grãos que cobre parte dos custos de formação da pastagem.

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Multi-centre data repositories like the Alzheimer's Disease Neuroimaging Initiative (ADNI) offer a unique research platform, but pose questions concerning comparability of results when using a range of imaging protocols and data processing algorithms. The variability is mainly due to the non-quantitative character of the widely used structural T1-weighted magnetic resonance (MR) images. Although the stability of the main effect of Alzheimer's disease (AD) on brain structure across platforms and field strength has been addressed in previous studies using multi-site MR images, there are only sparse empirically-based recommendations for processing and analysis of pooled multi-centre structural MR data acquired at different magnetic field strengths (MFS). Aiming to minimise potential systematic bias when using ADNI data we investigate the specific contributions of spatial registration strategies and the impact of MFS on voxel-based morphometry in AD. We perform a whole-brain analysis within the framework of Statistical Parametric Mapping, testing for main effects of various diffeomorphic spatial registration strategies, of MFS and their interaction with disease status. Beyond the confirmation of medial temporal lobe volume loss in AD, we detect a significant impact of spatial registration strategy on estimation of AD related atrophy. Additionally, we report a significant effect of MFS on the assessment of brain anatomy (i) in the cerebellum, (ii) the precentral gyrus and (iii) the thalamus bilaterally, showing no interaction with the disease status. We provide empirical evidence in support of pooling data in multi-centre VBM studies irrespective of disease status or MFS.

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Relaxation rates provide important information about tissue microstructure. Multi-parameter mapping (MPM) estimates multiple relaxation parameters from multi-echo FLASH acquisitions with different basic contrasts, i.e., proton density (PD), T1 or magnetization transfer (MT) weighting. Motion can particularly affect maps of the apparent transverse relaxation rate R2(*), which are derived from the signal of PD-weighted images acquired at different echo times. To address the motion artifacts, we introduce ESTATICS, which robustly estimates R2(*) from images even when acquired with different basic contrasts. ESTATICS extends the fitted signal model to account for inherent contrast differences in the PDw, T1w and MTw images. The fit was implemented as a conventional ordinary least squares optimization and as a robust fit with a small or large confidence interval. These three different implementations of ESTATICS were tested on data affected by severe motion artifacts and data with no prominent motion artifacts as determined by visual assessment or fast optical motion tracking. ESTATICS improved the quality of the R2(*) maps and reduced the coefficient of variation for both types of data-with average reductions of 30% when severe motion artifacts were present. ESTATICS can be applied to any protocol comprised of multiple 2D/3D multi-echo FLASH acquisitions as used in the general research and clinical setting.

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Foi realizado um estudo com o objetivo de verificar os efeitos da substituição do milho pelo triticale em dietas para frangos de corte. Foram utilizados 1.560 pintos de corte sendo metade de cada sexo, os quais foram criados de 1 até 42 dias de idade. O delineamento experimental foi em blocos casualizados, com cinco tratamentos (T1=0, T2=25, T3=50, T4=75% de substituição do milho por triticale e T5= uma dieta à base de triticale e farelo de soja). Utilizaram-se seis repetições de cada sexo de 26 aves em cada tratamento. As dietas foram isocalóricas e isoprotéicas. Foi verificado efeito de sexo (P<0,05), exceto na conversão alimentar média na primeira fase. Os machos apresentaram melhor desempenho do que as fêmeas. A interação entre sexo e tratamento não foi significativa (P>0,05). De acordo com os resultados médios de desempenho, verificou-se que é possível substituir o milho por triticale em até 75%, sem afetar o desempenho. O uso do triticale será econômico, em dietas para machos e fêmeas juntos, quando o seu custo representar 63, 46 e 45% do preço do milho, nas substituições de 25, 50 e 75%, respectivamente. No tocante ao T5, mesmo com desempenho inferior em relação ao T1, é economicamente viável se o preço do triticale representar 42% do preço do milho.

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No presente estudo, aplicou-se a diluição qualitativa da dieta com o objetivo de determinar os efeitos das diferentes diluições (25% e 50%) das rações no desempenho de frangos de corte criados até 42 dias de idade. Utilizou-se, para a diluição, casca de soja na dieta inicial (21,5% de PB e 3.050 kcal/kg de EM), e os tratamentos experimentais foram baseados nessas dietas e distribuídos de forma contínua, durante sete dias, ou de forma intercalada, com a ração não diluída. Os tratamentos aplicados foram: T1: ração inicial (testemunha); T2 e T3: ração inicial diluída com 25% e 50% de casca de soja, respectivamente, fornecida durante sete dias; T4 e T5: ração inicial diluída com 25% e 50% de casca de soja, respectivamente, fornecida nos dias 7, 9, 11 e 13, intercalada com a ração testemunha nos dias 8,10 e 12. As aves sob restrição alimentar mostraram pesos corporais menores (P<0,05) em comparação com as aves do tratamento-testemunha. Não houve diferenças quanto a conversão alimentar acumulada (0-42 dias) entre os tratamentos da restrição. O oferecimento de forma intercalada das rações diluídas conferiu menores perdas no ganho de peso e no peso corporal. Não houve diferença quanto a mortalidades entre os tratamentos. As aves não apresentaram crescimento compensatório, o que parece estar associado ao padrão de curva de crescimento apresentada pela linhagem.

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To generate peripheral T cells that are both self-MHC restricted and self-MHC tolerant, thymocytes are subjected to positive and negative selection. How the TCR discriminates between positive and negative selection ligands is not well understood, although there is substantial evidence that the CD4 and CD8 coreceptors play an important role in this cell fate decision. We have previously identified an evolutionarily conserved motif in the TCR, the alpha-chain connecting peptide motif (alpha-CPM), which allows the TCR to deliver positive selection signals. Thymocytes expressing alpha-CPM-deficient receptors do not undergo positive selection, whereas their negative selection is not impaired. In this work we studied the ligand binding and receptor function of alpha-CPM-deficient TCRs by generating T cell hybridomas expressing wild-type or alpha-CPM-deficient forms of the T1 TCR. This K(d)-restricted TCR is specific for a photoreactive derivative of the Plasmodium berghei circumsporozoite peptide(252-260) IASA-YIPSAEK(ABA)I and is therefore amenable to TCR photoaffinity labeling. The experiments presented in this work show that alpha-CPM-deficient TCRs fail to cooperate with CD8 to enhance ligand binding and functional responses.

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Objectifs: Déterminer la fréquence et les facteurs prédictifs de l'effet T2 shine-through dans l'hémangiome hépatique. Matériels et méthodes: Entre janvier 2010 et novembre 2011, l'imagerie par résonance magnétique du foie de 149 patients avec 388 hémangiomes hépatiques a été revue rétrospectivement. Les caractéristiques lésionnelles: la taille, la localisation, le signal et l'aspect en T1, T2 et en diffusion, l'effet T2 shine-through, le coefficient apparent de diffusion des hémangiomes hépatiques et du foie et type de rehaussement ont été évalués. Résultats: L'effet T2 shine-through était observé dans 204/388 (52.6%) des hémangiomes hépatiques et 100 (67.1%) patients. L'ADC moyen des hémangiomas avec T2 shine-through effect était significativement plus bas que les hémangiomas sans T2 shine-through effect (2.0 +/- 0.48 vs 2.38 +/- 0.45 10"3 mm2/s, P &lt; .0001). L'analyse multivariée retrouvait comme facteurs indépendants de la présence d'un effet T2 shine-through un hypersignal sur les images fat- suppressed T2-weighted fast spin-echo, les hémangiomes avec un rehaussement classique et retardé, et l'ADC du foie. Conclusion: Le T2 shine-through effect est fréquemment observé dans les hémangiomes hépatiques et dépend des caractéristiques lésionnelles. Sa présence ne remet pas en question le diagnostic lorsque les signes IRM typiques sont présents.

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INTRODUCTION: In patients with multiple sclerosis (MS), conventional magnetic resonance imaging (MRI) provides only limited insights into the nature of brain damage with modest clinic-radiological correlation. In this study, we applied recent advances in MRI techniques to study brain microstructural alterations in early relapsing-remitting MS (RRMS) patients with minor deficits. Further, we investigated the potential use of advanced MRI to predict functional performances in these patients. METHODS: Brain relaxometry (T1, T2, T2*) and magnetization transfer MRI were performed at 3T in 36 RRMS patients and 18 healthy controls (HC). Multicontrast analysis was used to assess for microstructural alterations in normal-appearing (NA) tissue and lesions. A generalized linear model was computed to predict clinical performance in patients using multicontrast MRI data, conventional MRI measures as well as demographic and behavioral data as covariates. RESULTS: Quantitative T2 and T2* relaxometry were significantly increased in temporal normal-appearing white matter (NAWM) of patients compared to HC, indicating subtle microedema (P = 0.03 and 0.004). Furthermore, significant T1 and magnetization transfer ratio (MTR) variations in lesions (mean T1 z-score: 4.42 and mean MTR z-score: -4.09) suggested substantial tissue loss. Combinations of multicontrast and conventional MRI data significantly predicted cognitive fatigue (P = 0.01, Adj-R (2) = 0.4), attention (P = 0.0005, Adj-R (2) = 0.6), and disability (P = 0.03, Adj-R (2) = 0.4). CONCLUSION: Advanced MRI techniques at 3T, unraveled the nature of brain tissue damage in early MS and substantially improved clinical-radiological correlations in patients with minor deficits, as compared to conventional measures of disease.

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AIM: The goal of the present work was to compare outcomes of definitive concurrent cisplatin-based chemoradiotherapy (CRT) with cetuximab-based bioradiotherapy (BRT) in locally advanced head-and-neck squamous cell carcinoma (HNSCC). PATIENTS AND METHODS: Between 2006 and 2012, 265 patients with locally advanced HNSCC were treated at our institution with CRT (n&#8201;=&#8201;194; 73&#8201;%) with three cycles of cisplatin (100 mg/m(2), every 3 weeks) or BRT (n&#8201;=&#8201;71; 27&#8201;%) with weekly cetuximab. Patients receiving BRT had more pre-existing conditions (Charlson index &#8805;&#8201;2) than the CRT group (p&#8201;=&#8201;0.005). RESULTS: Median follow-up was 29 months. In all, 56&#8201;% of patients treated with CRT received the planned three cycles (92&#8201;% at least two cycles) and 79&#8201;% patients treated with BRT received six cycles or more. The 2-year actuarial overall survival (OS) and progression-free survival (PFS) were 72&#8201;% and 61&#8201;%, respectively. In the multivariate analysis (MVA), T4 stage, N2-3 stage, smoking status (current smoker as compared with never smoker), and non-oropharyngeal locations predicted for OS, whereas BRT association with OS was of borderline significance (p&#8201;=&#8201;0.054). The 2-year actuarial locoregional control (LRC) and distant control (DC) rates were 73 and 79&#8201;%, respectively. CRT was independently associated with an improved LRC (2-year LRC: 76&#8201;% for CRT vs. 61&#8201;% for BRT) and DC (2-year LRC: 81&#8201;% for CRT vs. 68&#8201;% for BRT) in comparison with BRT (p&#8201;<&#8201;0.001 and p&#8201;=&#8201;0.01 in the MVA). Subgroup analyses showed that T4 patients benefited significantly from CRT (vs. BRT) in LRC, while T1-3 did not. BRT patients had more G3-4 skin complications (p&#8201;<&#8201;0.001) and CRT patients had higher rates of feeding tube placement (p&#8201;=&#8201;0.006) and G3-4 gastrointestinal toxicities (p&#8201;<&#8201;0.001). CONCLUSION: This retrospective analysis showed a better LRC in locally advanced HNSCC treated by cisplatin-based CRT than cetuximab-based BRT, and a nonsignificant trend towards an improved OS.

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The objective of this research was to evaluate the effect of the insect resistant soybean genotype IAC 17 on reproductive characteristics of Podisus nigrispinus (Dallas) (Heteroptera: Pentatomidae) females compared to the soybean insect susceptible genotype UFV 16. Treatments were: T1) females of P. nigrispinus fed on plants of the UFV 16 and Anticarsia gemmatalis Hübner (Lepidoptera: Noctuidae) caterpillars reared on leaves of this variety; T2) females of P. nigrispinus fed on plants of the IAC 17 and A. gemmatalis caterpillars reared on leaves of this variety. Longevity of females, pre-oviposition, oviposition and pos-oviposition periods, number of eggs and egg masses/female, egg weight, interval between egg mass laying, number of eggs/egg mass, percentage of nymphs, number of nymphs/female and total number of prey killed/female of P. nigrispinus were evaluated. Most of the characteristics evaluated showed similar results between treatments, but the oviposition period was longer for females reared on the resistant genotype than on the susceptible one and the percentage of total females that laid eggs was lower on the IAC 17. Also, the resistant genotype caused higher mortality of P. nigrispinus females at the beginning of its adult stage and egg production by females of this predator was better spread along its adult stage with this resistant genotype. On the other hand, results suggest no effect of the resistant genotype on the offspring of this predator.