Lesões hepáticas focais benignas nas imagens de ressonância magnética pesadas em difusão : o papel das imagens pesadas em difusão (DWI) e do coeficiente aparente de difusão (ADC) na caracterização e no diagnóstico diferencial

• Autor(a) principal: Justo, Jonatan William Rodrigues
• Data de Publicação: 2019
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da PUC_RS
• Texto Completo: http://tede2.pucrs.br/tede2/handle/tede/8653
• topic: Diffusion Magnetic Resonance Imaging; Diffusion MRI; Hemangioma; Focal Nodular Hyperplasias; Neoplasm Metastasis; Adenoma, Liver Cell; CIENCIAS DA SAUDE::MEDICINA

Objective: Our study analyzed the role of diffusion and of ADC in the differentiation between solid hepatic lesions in non-cirrhotic patients. Materials and methods: a retrospective analysis of consecutive exams from January 2015 to June 2018 was carried out in a tertiary hospital in Porto Alegre, and those with solid focal liver lesions were selected. The examinations were evaluated by two radiologists with more than 10 years' experience in the area and the ADC collected by a physician with 4 years of experience. Values of ADC and hepatic ADC were obtained to calculate the parameterized ADC. The Receiver Operating Characteristic (ROC) curve was used, with determination of the cut-off point for the ADC and the parameterized ADC to determine its ability to differentiate the lesions. A Poisson regression model was applied to evaluate possible confounding variables of the sample. Results: The total of 118 focal hepatic lesions (78 benign lesions, 11 adenomas, 33 hemangiomas, 34 focal nodular hyperplasia, and 40 malignant lesions, all metastases) were observed in the final analysis. The mean ADC and parameterized ADC values for benign lesions were higher than those for malignant lesions (1,420 x 10-3 mm2 / s for 1,130 x 10-3 mm2 / s and 1,350 x 10-3 mm2 / s for 1,140 x 10-3 mm2 / s with p <0.001 and 0.036 respectively). The analysis of the ROC curve showed area under the curve of 0.79 and 0.67 respectively for the ADC and parameterized ADC (with cut-offs of 1.19 x 10-3mm2 / s and 1.08x10-3mm2 / s), with sensitivities and specificities of 75% and 73.1% for the ADC and 65% and 69.2% for the parameterized ADC. The age of the patient and previous oncologic history were variables that showed an association with malignancy of lesions even after adjustment (with a sevenfold increase in chance in patients with positive oncologic history). Conclusion: the use of diffusion images, of ADC and of pamameterized ADC in the characterization of solid benign lesions and their differentiation with metastases is appropriate. These results help in the elaboration of the differential diagnosis of focal liver lesions in livers of non-cirrhotic patients.