ABSTRACT Objective: Identifying significant fibrosis is crucial to evaluate the prognosis and therapeutic interventions in patients with nonalcoholic fatty liver disease (NAFLD). We assessed the performance of acoustic radiation force impulse (ARFI) elastography, APRI, FIB-4, Forns, NFS and BARD scores in determining liver fibrosis in severe obesity. Subjects and methods: A prospective study included 108 patients undergoing bariatric surgery. Liver biopsy specimens were obtained intraoperatively and classified according to the NAFLD Activity Score. Patients were assessed with serological markers and shear wave velocity of the liver was measured with the Siemens S2000 ultrasound system preoperatively. Optimal cut-off values were determined using the area under the receiver operating characteristic curves (AUROC). Results: In the entire cohort prevalence of NAFLD was 80.6%, steatohepatitis 25.9% and significant fibrosis 19.4%. The best tests for predicting significant fibrosis were FIB-4 and Forns scores (both AUROC 0.78), followed by APRI (AUROC 0.74), NFS (AUROC 0.68), BARD (AUROC 0.64) and ARFI (AUROC 0.62). ARFI elastography was successful in 73% of the patients. Higher body mass index (BMI) correlated with invalid ARFI measurements. In patients with BMI < 42 kg/m2, ARFI showed 92.3% sensitivity and 82,6% specificity for the presence of significant fibrosis, with AUROC 0.86 and cut-off 1.32 m/s. Conclusions: FIB-4 and Forns scores were the most accurate for the prediction of significant fibrosis in bariatric patients. Applicability and accuracy of ARFI was limited in individuals with severe obesity. In patients with BMI < 42 kg/m2, ARFI elastography was capable for predicting significant fibrosis with relevant accuracy.

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.

CONTEXTO: O hemangioma hepático apresenta incidência entre 0,4% a 20% na população e a ultrassonografia convencional é geralmente o primeiro método diagnóstico a identificá-lo como achado incidental. A ultrassonografia com contrastes de segunda geração vem sendo utilizada em várias áreas da hepatologia, com resultados semelhantes à tomografia computadorizada e a ressonância magnética no diagnóstico dos hemangiomas hepáticos. OBJETIVO: Avaliar a concordância entre a ultrassonografia com o contraste perflutreno e a ressonância magnética no diagnóstico dos hemangiomas hepáticos. MÉTODOS: Foram analisados prospectivamente 37 pacientes entre janeiro de 2006 e agosto de 2008 e identificados 57 nódulos como achados incidentais de exame de ultrassom de rotina. Nos 37 pacientes, foi administrado o contraste perflutreno, sem reações adversas. Os 37 pacientes realizaram exames de ressonância magnética. RESULTADOS: A ultrassonografia convencional identificou em 15 pacientes nódulos com características típicas de hemangiomas e em 22 pacientes com nódulos com outras características Em 35 pacientes as características do contraste foram compatíveis com hemangiomas hepáticos. CONCLUSÕES: A concordância entre a ultrassonografia com contraste e a ressonância magnética foi de 94,5% e nos casos discordantes o diagnóstico foi realizado pela ressonância magnética. No caso indeterminado na ultrassonografia com contraste, a ressonância magnética foi repetida em 3 meses, confirmando o diagnostico de hemangioma hepático. No caso com nódulo sugestivo de malignidade na ultrassonografia com contraste, foi realizada biopsia do nódulo, com anatomopatológico de hemangioma hepático. A ultrassonografia com contraste apresenta vantagens de maior acesso a população e custos menores em relação à ressonância magnética. Os resultados deste trabalho sugerem novo protocolo para nódulos hepáticos identificados incidentalmente em exames de ultrassonografia convencional. Nos hemangiomas típicos, a ultrassonografia convencional seria suficiente. Nos casos com nódulos não definidos, a ultrassonografia com contraste a ser indicado, que ao confirmar o diagnóstico de hemangioma hepático, encerraria a instigação diagnóstica.

CONTEXT:The incidence of hepatic hemangiomas ranges from 0.4% to 20% in the general population. Conventional ultrasound is usually the first diagnostic method to identify these hemangiomas, typically as an incidental finding. Ultrasonography with second generation contrast materials is being used in various areas of hepatology, yielding similar results to those obtained with computerized tomography and magnetic resonance imaging in the diagnosis of hepatic hemangiomas. OBJECTIVE: To evaluate the agreement between ultrasound with perflutrene contrast and magnetic resonance imaging in the diagnosis of hepatic hemangiomas. METHODS: A total of 37 patients were prospectively examined between January 2006 and August 2008. A total of 57 hepatic nodules were documented in this group as incidental findings on routine ultrasound exams. The 37 patients were administered perflutrene contrast without adverse reactions, and were all submitted to magnetic resonance exams. RESULTS: Conventional ultrasound identified 15 patients with nodules typical of hemangiomas and 22 patients with other nodules. In 35 patients, the contrast characteristics were consistent with hepatic hemangiomas. CONCLUSION: Agreement between the data obtained from ultrasound with contrast and magnetic resonance was 94.5%. In discordant cases, the magnetic resonance diagnosis prevailed. In the case which presented indeterminate findings on contrast ultrasonography, magnetic resonance was repeated after 3 months, confirming the diagnosis of a hepatic hemangioma. A biopsy was performed on the suspected malignant nodule which also confirmed the presence of a hepatic hemangioma. Ultrasonography with contrast has the advantages of being more accessible to the public at large and lower cost than magnetic resonance. The results of our study highlight the need for a new protocol in hepatic nodules incidentally identified on conventional ultrasonography. In the case of typical hemangiomas, conventional ultrasound is sufficient for diagnosis. However, for poorly defined nodules, ultrasonography with contrast is indicated. After confirming the presence of a hepatic hemangioma on contrast ultrasonography, no further exams are needed to finalize the diagnosis.

OBJETIVO: O objetivo deste estudo foi avaliar o significado do Doppler espectral por meio da obtenção do índice de resistência vascular na diferenciação entre lesões mamárias benignas e malignas. MATERIAIS E MÉTODOS: Dezenove lesões malignas e 18 benignas, diagnosticadas por estudo histológico, foram submetidas previamente a análise de sua vascularização por meio do Doppler espectral para se obter o índice de resistência vascular. RESULTADOS: Observou-se diferença estatisticamente significante (p < 0,001) entre os valores médios do índice de resistência para os resultados benigno e maligno (0,62x 0,80, respectivamente), em nódulos maiores que 1 cm. Um índice de resistência 0,69 foi altamente associado a lesões malignas, com sensibilidade de 84,2%, especificidade de 88,9%, taxa de falso-positivo de 11,1% e taxa de falso-negativo de 15,8%. CONCLUSÃO: A análise do índice de resistência vascular pode fornecer grande auxílio na avaliação das lesões nodulares da mama maiores que 1 cm, em conjunto com as informações obtidas por meio da escala de cinzas, com elevada sensibilidade e especificidade.

OBJECTIVE: The present study was aimed at evaluating the role played by spectral Doppler as a method to measure the vascular resistance index in the differentiation between benign and malignant breast lesions. MATERIALS AND METHODS: Nineteen malignant and 18 benign lesions histologically diagnosed had their vascularization previously analyzed through the resistance index. RESULTS: A statistically significant difference (p < 0.001) was observed between the mean values of resistance index for benign and malignant lesions (respectively 0.62x 0.80) in nodular breast lesions greater than 1 cm. A resistance index 0.69 was highly associated with malignant lesions, with 84.2% sensitivity, 88.9% specificity, false-positive rate of 11.1%, and false-negative rate of 15.8%. CONCLUSION: The analysis of vascular resistance index combined with findings on grayscale sonographic images can be of great assistance in the assessment of nodular breast lesions greater than 1 cm, with high sensitivity and specificity.