RESUMO CONTEXTO E OBJETIVO: Biópsias são utilizadas para avaliar fibrose após transplante de fígado. O estudo objetivou avaliar a elasticidade hepática após transplante por meio de um exame não invasivo, a elastografia ARFI (acoustic radiation force imaging ), correlacionando-a com a análise histológica. TIPO DE ESTUDO E LOCAL: Estudo transversal em hospital público universitário. MÉTODOS: Todos os pacientes consecutivamente operados entre 2002 e 2010, com indicação para biópsia, foram avaliados por elastografia. O radiologista avaliando ARFI e o patologista fazendo exames anatomopatológicos estavam cegos para as avaliações um do outro. RESULTADOS: No período do estudo, 33 pacientes foram incluídos. A indicação para o transplante foi cirrose por hepatite C em 21 (63%). As biópsias mostraram ausência de fibrose (F0) em 10 pacientes, F1 em 11, F2 em 8, F3 em 4 e nenhum caso de F4 (cirrose). A diferença nos valores de ARFI (grau de fibrose) foi de 0,26 (intervalo de confiança, IC, de 95%: 0,07-0,52) entre os grupos F0-F1 e F2-F4 (P = 0,04). A área sob a curva de 0,74 (IC: 0,55-0,94) e o valor de corte de 1,29 m/s entre os grupos resultaram na melhor relação entre sensibilidade e especificidade, de 0,57. A sensibilidade (0,66; IC: 0,50-0,83) foi menor que a especificidade (0,85; IC: 0,72-0,97). Não houve diferença significativa em ARFI entre pacientes com hepatite C e aqueles com outras doenças. CONCLUSÕES: Os valores obtidos com a elastografia não foram afetados por reação inflamatória ou alterações anatômicas. Foi identificado ponto de corte de 1,29 m/s que separa pacientes com ou sem fibrose significativa.

ABSTRACT CONTEXT AND OBJECTIVE: Biopsies are used after liver transplantation to evaluate fibrosis. This study aimed to evaluate the elasticity of transplanted livers by means of a non-invasive examination, acoustic radiation force imaging (ARFI) elastography, correlating the results with the histological analysis. DESIGN AND SETTING: Cross-sectional study in a public university hospital. METHODS: All patients consecutively operated between 2002 and 2010 with an indication for biopsy were evaluated by means of elastography. The radiologist evaluating ARFI and the pathologist doing anatomopathological examinations were blinded to each other's evaluations. RESULTS: During the study period, 33 patients were included. The indication for transplantation was cirrhosis due to hepatitis C in 21 cases (63%). Liver biopsies showed absence of fibrosis (F0) in 10 patients, F1 in 11, F2 in 8 and F3 in 4. There were no cases of F4 (cirrhosis). The difference in ARFI values (degree of fibrosis) was 0.26 (95% confidence interval, CI: 0.07-0.52) between the groups F0-F1 and F2-F4 (P = 0.04). An area under the curve of 0.74 (CI: 0.55-0.94) and a cutoff of 1.29 m/s between the groups resulted in the best relationship between sensitivity and specificity. Sensitivity (0.66; CI: 0.50-0.83) was lower than specificity (0.85; CI: 0.72-0.97). There was no significant difference in ARFI between patients with hepatitis C and those with other diseases. CONCLUSIONS: The values obtained from elastography were not affected by inflammatory reaction or anatomical alterations. A cutoff point of 1.29 m/s separating patients with or without significant fibrosis was identified.

Financial and insurance theories explain that large widely-held corporations manage corporate risks if doing so is costective to reduce frictional costs such as taxes, agency costs and financial distress costs. A large number of previous empirical studies, most in the U.S., have tested the hypotheses underlying corporate risk management with financial derivative instruments. In order to quantify corporate hedge demand, most previous studies have used the ratio of principal notional amount of derivatives to company size, although they recognize that company size is not an appropriate proxy for financial risk. This paper analyzes the interest-rate-risk hedge demand by Australian companies, measured through the ratio of principal notional amount of interest rate derivatives to interest-rate-riskbearing liabilities. Modern panel data methods are used, with two panel data sets from 1998 to 2003 (1102 and 465 observations, respectively). Detailed information about interest-rate-risk exposures was available after manual data collection from financial annual reports, which was only possible due to specific reporting requirements in Australian accounting standards. Regarding the analysis of the extent of hedge, our measurement of interest-rate-risk exposures generates some significant results di erent from those found in previous studies. For example, this study shows that total leverage (total debt ratio) is not significantly important to interest-rate-risk hedge demand and that, instead, this demand is related to the specific risk exposure in the interest bearing part of the firms liabilities. This study finds significant relations of interest-rate-risk hedge to company size, floating-interest-rate debt ratio, annual log returns, and company industry type (utilities and non-banking financial institutions).