RESUMO
BACKGROUND: Diffusion-weighted imaging (DWI) provides insight into the pathophysiology underlying renal dysfunction. Variants of DWI include intravoxel incoherent motion (IVIM), which differentiates between microstructural diffusion and vascular or tubular flow, and diffusion tensor imaging (DTI), which quantifies diffusion directionality. PURPOSE: To investigate the reproducibility of joint IVIM-DTI and compare controls to presurgical renal mass patients. STUDY TYPE: Prospective cross-sectional. SUBJECTS: Thirteen healthy controls and ten presurgical renal mass patients were scanned. Ten controls were scanned twice to investigate reproducibility. FIELD STRENGTH/SEQUENCE: Subjects were scanned on a 3T system using 10 b-values and 20 diffusion directions for IVIM-DTI in a study approved by the local Institutional Review Board. ASSESSMENT: Retrospective coregistration and measurement of joint IVIM-DTI parameters were performed. STATISTICAL ANALYSIS: Parameter reproducibility was defined as intraclass correlation coefficient (ICC) >0.7 and coefficient of variation (CV) <30%. Patient data were stratified by lesion side (contralateral/ipsilateral) for comparison with controls. Corticomedullary differentiation was evaluated. RESULTS: In controls, the reproducible subset of REnal Flow and Microstructure AnisotroPy (REFMAP) parameters had average ICC = 0.82 and CV = 7.5%. In renal mass patients, medullary fractional anisotropy (FA) was significantly lower than in controls (0.227 ± 0.072 vs. 0.291 ± 0.044, P = 0.016 for the kidney contralateral to the mass and 0.228 ± 0.070 vs. 0.291 ± 0.044, P = 0.018 for the kidney ipsilateral). In the kidney ipsilateral to the mass, cortical Dp,radial was significantly higher than in controls (P = 0.012). Conversely, medullary Dp,axial was significantly lower in contralateral than ipsilateral kidneys (P = 0.027) and normal controls (P = 0.044). DATA CONCLUSION: REFMAP-MRI parameters provide unique information regarding renal dysfunction. In presurgical renal mass patients, directional flow changes were noted that were not identified with IVIM analysis alone. Both contralateral and ipsilateral kidneys in patients show reductions in structural diffusivities and anisotropy, while flow metrics showed opposing changes in contralateral vs. ipsilateral kidneys. LEVEL OF EVIDENCE: 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018.
Assuntos
Imagem de Difusão por Ressonância Magnética , Neoplasias Renais/diagnóstico por imagem , Rim/diagnóstico por imagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Anisotropia , Índice de Massa Corporal , Estudos Transversais , Imagem de Tensor de Difusão , Feminino , Humanos , Aumento da Imagem/métodos , Interpretação de Imagem Assistida por Computador/métodos , Processamento de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Movimento (Física) , Distribuição Normal , Período Pré-Operatório , Estudos Prospectivos , Reprodutibilidade dos Testes , Estudos RetrospectivosRESUMO
CONTEXTUALIZAÇÃO: A diminuição da força muscular em idosos tem impacto na funcionalidade. Programas de reforço muscular são propostos, porém existem controvérsias quanto ao efeito de alongamentos prévios no ganho de força muscular. OBJETIVO: Verificar o impacto do alongamento estático no ganho de força dos músculos extensores de joelho em idosas da comunidade após programa de treinamento. MÉTODOS:Trata-se de um estudo quase-experimental, em que se realizou um programa de exercícios de fortalecimento muscular dos extensores de joelho durante 10 semanas, com avaliação final de 12 idosas da comunidade divididas em dois grupos: AE - exercícios com carga e alongamentos prévios em todas as sessões, média de idade de 73,8 (±5,36) anos e E - mesmos exercícios com carga do grupo acima, sem a realização de alongamentos prévios, média de idade de 72,14 (±5,43) anos. Para avaliar o ganho de força muscular dos extensores de joelho, utilizou-se o dinamômetro isocinético Biodex System 3 Pro, no modo concêntrico, na velocidade de movimento angular de 60 e 180º/segundos (s) e, para a análise, a diferença das médias da pré e da pós-intervenção da variável trabalho, normalizada pelo peso corporal. RESULTADOS: Os dados apresentaram-se normais pelo teste de Shapiro-Wilk (p>0,266). Quando comparadas as médias da diferença da pré e da pós-intervenção pelo teste t para amostras independentes, não houve diferença significativa em nenhum dos membros e nas velocidades avaliadas (p>0,383). CONCLUSÃO: O alongamento estático prévio não interferiu no ganho de força muscular após um programa de fortalecimento de 10 semanas na população estudada. Artigo registrado no ISRCTN register sob o número ISRCTN62824599.
BACKGROUND: The decrease in muscle strength in older adults has an impact on functionality. Muscle strengthening programs have been proposed, however there is some controversy surrounding the effects of stretching prior to strengthening exercises on muscle strength gain. OBJECTIVE: To verify the impact of static stretching on the gain in knee-extensor strength of community-dwelling elderly women after a training program. METHODS: This was a quasi-experimental study that included a ten-week knee-extensor strengthening program and a final assessment of 12 community-dwelling elderly women divided into two groups: group SE - strengthening exercises with prior static stretching in all sessions, mean age 73.8 (±5.36) years; and group E - same strengthening exercises as SE without prior stretching, mean age 72.14 (±5.43) years. To measure knee-extensor strength gains, we used the isokinetic dynamometer Biodex System 3 Pro, in concentric mode at angular velocities of 60º and 180º/s, and for statistical analysis we used the difference between pre- and post-intervention means of work adjusted by body weight. RESULTS: The data showed normality in the Shapiro-Wilk test (p>0.266). When comparing the differences between the pre- and post-intervention means using the t test for independent samples, there was no significant difference in any of the limbs at the velocities evaluated (p>0.383). CONCLUSION: Previous static stretching did not interfere in muscle strength gain following a ten-week muscle strengthening program in the population studied. Article registered in the ISRCTN register under number ISRCTN62824599.
Assuntos
Idoso , Feminino , Humanos , Exercício Físico , Joelho , Força Muscular , Exercícios de Alongamento MuscularRESUMO
BACKGROUND: The decrease in muscle strength in older adults has an impact on functionality. Muscle strengthening programs have been proposed, however there is some controversy surrounding the effects of stretching prior to strengthening exercises on muscle strength gain. OBJECTIVE: To verify the impact of static stretching on the gain in knee-extensor strength of community-dwelling elderly women after a training program. METHODS: This was a quasi-experimental study that included a ten-week knee-extensor strengthening program and a final assessment of 12 community-dwelling elderly women divided into two groups: group SE - strengthening exercises with prior static stretching in all sessions, mean age 73.8 (± 5.36) years; and group E - same strengthening exercises as SE without prior stretching, mean age 72.14 (± 5.43) years. To measure knee-extensor strength gains, we used the isokinetic dynamometer Biodex System 3 Pro, in concentric mode at angular velocities of 60º and 180º/s, and for statistical analysis we used the difference between pre- and post-intervention means of work adjusted by body weight. RESULTS: The data showed normality in the Shapiro-Wilk test (p > 0.266). When comparing the differences between the pre- and post-intervention means using the t test for independent samples, there was no significant difference in any of the limbs at the velocities evaluated (p>0.383). CONCLUSION: Previous static stretching did not interfere in muscle strength gain following a ten-week muscle strengthening program in the population studied. Article registered in the ISRCTN register under number ISRCTN62824599.