Ultrasound method applied to characterize healthy femoral diaphysis of Wistar rats in vivo

A simple experimental protocol applying a quantitative ultrasound (QUS) pulse-echo technique was used to measure the acoustic parameters of healthy femoral diaphyses of Wistar rats in vivo. Five quantitative parameters [apparent integrated backscatter (AIB), frequency slope of apparent backscatter (FSAB), time slope of apparent backscatter (TSAB), integrated reflection coefficient (IRC), and frequency slope of integrated reflection (FSIR)] were calculated using the echoes from cortical and trabecular bone in the femurs of 14 Wistar rats. Signal acquisition was performed three times in each rat, with the ultrasound signal acquired along the femur's central region from three positions 1 mm apart from each other. The parameters estimated for the three positions were averaged to represent the femur diaphysis. The results showed that AIB, FSAB, TSAB, and IRC values were statistically similar, but the FSIR values from Experiments 1 and 3 were different. Furthermore, Pearson's correlation coefficient showed, in general, strong correlations among the parameters. The proposed protocol and calculated parameters demonstrated the potential to characterize the femur diaphysis of rats in vivo. The results are relevant because rats have a bone structure very similar to humans, and thus are an important step toward preclinical trials and subsequent application of QUS in humans.

Prediction of death using the Mannheim Peritonitis Index in oncologic patients

O Índice de Peritonite de Mannheim (MPI) é um sistema de escore idealizado para avaliar o prognóstico de pacientes com peritonite. Realizamos um estudo retrospectivo de oito anos dos prontuários de 89 pacientes com doença maligna e peritonite submetidos a cirurgia. O índice médio foi de 26.6 pontos (5-47), com sensibilidade de 87,3 por cento e especificidade de 41,2 por cento. A melhor acurácia (69,7 por cento) foi obtida com o escore de 21. Concluimos que o MPI foi um preditor de morte confiável em pacientes oncológicos com peritonite e pode ser de utilidade no planejamento e avaliação de futuras formas de tratamento nestes pacientes.