Euterpe Olerácea (Açaí) as an alternative oral contrast agent in MRI of the gastrointestinal system: preliminary results - Córdova-Fraga, T.; Araújo, Dráulio Barros de; Sanchez, T. A.; Elias Júnior, Jorge; Carneiro, A. A. O.; Oliveira, Ricardo Brandt de; Sosa, M.; Baffa, Oswaldo (Magnetic Resonance Imaging, 2004)