Abstract This works aims to assess images obtained with administration of açai juice as compared to a manufactured standard iron oxide-based contrast employed as negative oral agents in Magnetic Resonance Cholangiopancreatography (MRCP), employing qualitative and quantitative evaluation. The research was developed with 64 patients submitted to MRCP exams (on 2 days) in a clinic of Curitiba city (Brazil). First (day 1), a manufactured iron oxide-based contrast (A) was offered and later (day 2), açai juice (contrast B) was given to patients. Radiologists (R1 and R2) evaluated the images, classifying them by a score (1-4). In order to have a quantitative assessment, Image J free software was employed generating plots of gray levels against distance of a chosen area of the bile duct interest region. Evaluating images for contrast A, R1 furnished an average score of 3.52 and R2 of 3.27. For contrast B, R1 provided 3.44 and R2 3.38. Both evaluators considered image quality with contrast A adequate for 62 patients. R1 considered adequate for 62 and R2 for 60 patients when using açai juice. By taking same images for all patients with Image J, a quantitative analysis was obtained, resulting correlation coefficient of 0.986 between average curves of contrasts A and B. Thus, açai juice is an adequate alternative as contrast agent in MRCP exams. Image J was employed as a new method for quantitative investigation of image quality, presenting good agreement with medical opinion.

Objetivo:Investigar, mediante quantificação da intensidade do sinal emitido em amostras, se a diluição do agente de contraste paramagnético com contraste iodado e xilocaína alteram o sinal emitido pelo meio de contraste paramagnético durante o exame de artrorressonância magnética, e aperfeiçoar a concentração de contraste paramagnético utilizada no exame.Materiais e Métodos:Foi realizada sequência de pulso fast spin eco ponderada em T1 com saturação de gordura, utilizando três diferentes concentrações de contraste paramagnético diluídas em solução salina, contraste iodado e xilocaína. As amostras foram colocadas em frascos e a análise gráfica da intensidade do sinal em função da concentração de contraste paramagnético foi realizada.Resultados:Constatou-se que as diluições de contraste paramagnético em contraste iodado e xilocaína diminuíram, em média, a intensidade do sinal em 20,67% para o contraste iodado e 28,34% para a xilocaína, em comparação com as amostras de concentração idêntica diluídas apenas em solução salina. Porém, o aumento da concentração de gadolínio nas amostras ocasionou a diminuição da intensidade do sinal emitido pelo gadolínio, para todas as diluições.Conclusão:Minimizar o uso do meio de contraste iodado e da xilocaína e/ou a utilização de uma concentração de gadolínio com 2,5 mmol/L, diluída em solução salina, irá aperfeiçoar a sensibilidade do exame de artrorressonância magnética.

Objective:To investigate the effects of dilution of paramagnetic contrast agent with iodinated contrast and xylocaine on the signal intensity during magnetic resonance arthrography, and to improve the paramagnetic contrast agent concentration utilized in this imaging modality.Materials and Methods:Samples specially prepared for the study with three different concentrations of paramagnetic contrast agent diluted in saline, iodinated contrast agent and xylocaine were imaged with fast spin echo T1-weighted sequences with fat saturation. The samples were placed into flasks and graphical analysis of the signal intensity was performed as a function of the paramagnetic contrast concentration.Results:As compared with samples of equal concentrations diluted only with saline, the authors have observed an average signal intensity decrease of 20.67% for iodinated contrast agent, and of 28.34% for xylocaine. However, the increased gadolinium concentration in the samples caused decrease in signal intensity with all the dilutions.Conclusion:Minimizing the use of iodinated contrast media and xylocaine and/or the use of a gadolinium concentration of 2.5 mmol/L diluted in saline will improve the sensitivity of magnetic resonance arthrography.

OBJETIVO: O presente estudo consistiu em investigar a influência da radiação ionizante por raios X e raios gama sobre a estabilidade molecular de diversos meios de contraste radiológicos utilizados em exames de diagnóstico por imagem, por meio da espectroscopia de ressonância magnética nuclear de ¹H e 13C. MATERIAIS E MÉTODOS: Oito diferentes meios de contraste iodados (três iônicos e cinco não iônicos) foram expostos à radiação por raios X e raios gama. Em seguida, espectros de ressonância magnética nuclear de ¹H e 13C{¹H} foram coletados. RESULTADOS: Os espectros de ressonância magnética nuclear de 13C{¹H} de ambos os meios de contraste iônicos e não iônicos irradiados por raios X ou raios gama mostraram que não houve alterações na composição química desses contrastes. CONCLUSÃO: Não há problemas em armazenar as amostras nas salas, ou próximo aos equipamentos em que são realizados os exames. Enfatiza-se que a radiação recebida pelas amostras durante os ensaios foi direta, enquanto em uma sala de exames de radiodiagnóstico a radiação é indireta e, portanto, os níveis de radiações nestes casos são bastante inferiores àqueles empregados neste estudo.

OBJECTIVE: The purpose of the present study was to investigate the influence of ionizing radiation from x-rays and gamma rays on the molecular structure stability of several radiologic contrast media employed in diagnostic imaging by means of ¹H and 13C nuclear magnetic resonance spectroscopy. MATERIALS AND METHODS: Eight different types of iodinated contrast media (three ionic and five non-ionic) were exposed to x-rays and gamma rays irradiation. Subsequently, the ¹H and 13C{¹H} nuclear magnetic resonance spectra of these contrast media were collected. RESULTS: The ¹H and 13C{¹H} nuclear magnetic resonance spectra of both ionic and non-ionic contrast media irradiated by x-rays or gamma rays demonstrated the absence of any alteration of the contrast media chemical composition. CONCLUSION: There is no problem in keeping contrast media inside examination rooms or close to radiological equipment. It is important to mention that, during the tests, the samples were directly irradiated, while in a radiology examination room, the irradiation is not direct and, therefore, radiation levels in these cases are much lower than those employed in the present study.