Imaging findings of abdominal gossypibomas

O termo gossipiboma é usado para descrever uma massa formada a partir de uma matriz de algodão cercada por uma reação inflamatória/granulomatosa. Sua incidência é estimada em 0,15% a 0,2%. O corpo estranho na cavidade abdominal pode servir de nicho para a proliferação de microrganismos e agir como foco primário para formação de abscessos e de peritonite. Vários estudos têm demonstrado a importância da correlação clínica com os diversos métodos de imagem (radiografia convencional, ultrassonografia, tomografia computadorizada e ressonância magnética) no diagnóstico dos gossipibomas. Este ensaio tem por objetivo demonstrar uma série de casos típicos de gossipibomas abdominais e ilustrar suas diversas formas de apresentação, com ênfase nos achados dos diferentes métodos de imagem, visando a familiarizar os radiologistas com esta enfermidade e seus principais diagnósticos diferenciais

AGREEMENT ON MRI DIAGNOSIS IN COMPRESSIVE MALIGNANT VERTEBRAL FRACTURES

ABSTRACT Objective: Verify interobserver and intraobserver agreement of malignant compressive vertebral fractures (MCVF) diagnosis using magnetic resonance imaging (MRI). Methods: We retrospectively included a lumbar spine MRI of 63 patients with non-traumatic compressive vertebral fracture diagnoses. Each lumbar vertebra was classified as: without fracture, with fracture of benign characteristics, or with fracture of malignant characteristics. Two medical residents in radiology, one musculoskeletal radiologist fellow, one musculoskeletal radiologist, and two spine surgeons evaluated MRI exams, independently and blindly. Each observer performed two readings, with a 15-day interval between evaluations. A simple Kappa coefficient was used to calculate the intra and interobserver agreement. The reference standard classification was based on bone biopsy or clinical, and imaging follow-up of at least two years, for diagnostic performance analysis. Diagnostic performance was assessed by calculating sensitivity, specificity, accuracy, and positive and negative predictive values with a 95% confidence interval (CI). Results: We observed substantial to perfect intraobserver agreement (kappa: 0.80 to 1.00) and substantial interobserver agreement (kappa 0.64 to 0.77). In general, the sensitivity for the detection of MCVF was moderate, except for the second-year radiology resident that achieved a lower sensitivity. The specificity, accuracy, and negative predictive value were high for all observers. Conclusion: MCVF diagnosis using MRI showed substantial interobserver agreement. The second-year medical resident achieved lower sensitivity but high specificity for MCVF. Regarding the seniors, there was no statistical significance between spine surgeons and the musculoskeletal radiologist. Level of Evidence III; Diagnostic

Vibro-acoustography characterization of the acoustic response of mice femora in an experimental ex vivo model

Introdução: O objetivo deste estudo foi avaliar o potencial da técnica de vibroacustografia (VA) na detecção de alterações ósseas associadas à osteoporose, utilizando um modelo animal. Métodos: O protocolo experimental incluiu três grupos de fêmures de camundongos: a) grupo controle, b) grupo com osteoporose e c) grupo com osteoporose e tratado com pamidronato, uma droga antirreabsortiva óssea. A avaliação óssea pela técnica de VA foi realizada em um tanque acústico. Um transdutor ultrassônico confocal gerou dois feixes focados de alta frequência (MHz), com uma diferença de frequências de 65 KHz entre eles. Esses dois feixes interagem entre si e com a amostra óssea, produzindo uma resposta acústica de baixa frequência que é registrada por um hidrofone. As curvas espectrais da VA foram processadas com a transformada rápida de Fourier, permitindo-se a obtenção de valores numéricos para cada grupo experimental, que carregam propriedades mecânicas das amostras. A aquisição da VA foi repetida três vezes. Utilizamos a microCT como técnica de referência e estimamos a correlação entre VA e parâmetros da microCT. A análise estatística incluiu o Coeficiente de Correlação Interclasse (ICC), comparações múltiplas ANOVA e o coeficiente de correlação de postos de Spearman. Resultados: A análise espectral da VA e os valores da área sob a curva (média; desvio padrão) foram, respectivamente, 1,29e-07 e 9,32e-08 para o grupo controle, 3,25e-08 e 2,16e-08 para o grupo com osteoporose e 1,50e-07 e 8.37e-08 para o grupo com osteoporose e tratado com pamidronato. A VA diferenciou os grupos experimentais (p <0,01) e os resultados foram reprodutíveis (ICC = 0,43 [IC 95% = 0,15 - 0,71]). Houve associação estatisticamente significante entre a VA e micro CT na conectividade (p <0,01; r = 0,80) e na densidade de conectividade (p <0,01; r = 0,76), e houve uma tendência de correlação entre a VA e o microCT no número de trabéculas (Tb.N) e na separação de trabéculas (Tb.Sp) (p = 0,06). Conclusão: A VA diferenciou os ossos do grupo controle e do grupo osteoporótico. Além disso, encontramos forte correlação positiva entre a VA e a conectividade óssea mensurada pela microCT.Introduction: This study aimed to evaluate the potential of vibro-acustography (VA) technique to detect bone alterations associated with osteoporosis, using an animal model. Methods: The experimental protocol included three groups of mice: a) control group, b) group with osteoporosis and c) group with osteoporosis and treated with pamidronate, an antiresorptive drug. The evaluation of bone by the VA technique was conducted in an acoustic tank. A confocal ultrasonic transducer generated two high frequency (MHz) focused beams, with a difference frequency of 65 KHz between them. These two beams interact with each other and with the bone sample, producing a low frequency acoustic response registered by a hydrophone. The VA spectral curves were processed with the fast Fourier transform, in order to obtain numerical values that are weighted in the mechanical properties of the samples. VA acquisition was repeated three times. We used microCT as the reference technique and estimated the correlation of VA and microCT parameters. Statistical analysis included Interclass Correlation Coefficient (ICC), ANOVA multiple comparisons and Spearman\'s rank correlation coefficient. Results: VA spectral analysis and area under the curve values (mean; st. desv.) were, respectively, 1.29e-07 and 9.32e-08 for the control group, 3.25e-08 and 2.16e-08 for the group with osteoporosis; and 1.50e-07 and 8.37e-08 for the group with osteoporosis treated with pamidronate. VA differentiate the experimental groups (p<0.01) and the results were reproducible (ICC = 0.43 [95%CI = 0.15 - 0.71]). There was a statistically significant relationship between VA and MicroCT in connectivity (p<0.01; r=0.80) and connectivity density (p<0.01; r=0.76) and a trend between VA and trabecular number (Tb.N) and trabecular s Tb.Sp (p=0.06). Conclusion: VA differentiated the bones from the control group and the osteoporotic group. In addition, we found a strong positive correlation between VA and bone connectivity measured by microCT

STUDY OF SECONDARY OSSIFICATION CENTERS OF THE ELBOW IN THE BRAZILIAN POPULATION

<div><p>ABSTRACT Objective: To evaluate the age in which the secondary ossification centers of the elbow appear and fuse in the Brazilian population. Methods: Nearly thirty radiographs were randomly selected for each age group from 0 to 18 years, with a total of 544 radiographs from 439 patients, between 2010 and 2015, without abnormalities secondary to trauma, metabolic or bone tumor diseases. Radiographs were retrospectively evaluated by two blind and independent observers, according to the presence or not of the ossification centers, and the fusion between them. Results: The age interval of appearance and fusion were, respectively: capitulum (0 to 1 year; 10 to 15 years), radius head (2 to 6 year; 12 to 16 years), medial epicondyle (2 to 8 years; 13 to 17 years), trochlea (5 to 11 years; 10 to 18 years), olecranon (6 to 11 years; 13 to 16 years), e lateral epicondyle (8 to 13 years; 12 to 16 years). Appearance and fusion were earlier in girls compared to boys (exception to capitulum and radius head). Conclusion: The chronological order was similar to the literature. For girls, the radius head and medial epicondyle appeared simultaneously. There was a tendency of the olecranon center to appear before the trochlea for both sexes. Level of Evidence III, Diagnostic Study.</p></div