Optimization of pineapple juice amount used as a negative oral contrast agent in magnetic resonance cholangiopancreatography.

To evaluate the potential variability of Manganese (Mn) in commercial pineapple juice (PJ) produced in different years and to identify the optimal Mn concentration in the correct amount of PJ to be administered prior to Magnetic Resonance Cholangiopancreatography (MRCP) in order to suppress the gastroduodenal (GD) liquid signal. The Mn concentration in PJ produced in different years was defined using Atomic Absorption Spectrometry. The optimal Mn concentration and the amount of PJ, were estimated in an in-vitro analysis, and were then prospectively tested in a population of patients who underwent MRCP. The results were compared with those achieved with the previous standard amount of PJ used in a similar population. The concentrations of Mn in commercial PJ produced in different years did not differ. A total amount of 150 ml (one glass) of PJ having a high Mn content (2.37 mg/dl) was sufficient for the suppression of the GD liquid signal, despite the additional dilution caused by GD liquids since it led to a final concentration of Mn of 0.5-1.00 mg/dl. The optimized single-dose oral administration of 150 ml (approximately one glass) of PJ having a high Mn concentration prior to MRCP was adequate to guarantee the correct amount of Mn to suppress the GD signal.