Definition

An orally bioavailable contrast agent formulation composed of manganese chloride tetrahydrate (MnCl2 4H2O), and the absorption promoters L-alanine and vitamin D3, that can potentially be used as a contrast enhancement agent during hepatobiliary magnetic resonance imaging (MRI). Upon oral administration of the manganese/L-alanine/vitamin D3-containing contrast agent formulation, L-alanine and vitamin D3 enhance the absorption of the poorly absorbable contrast agent manganese mainly from the small intestines. Upon absorption, the trace element manganese is taken up by normal, healthy hepatocytes. Due to the retention of manganese in the hepatocytes and its paramagnetic properties, this contrast agent enhances the visualization of normal liver tissue during an MRI. As liver tumor cells and liver metastases do not accumulate manganese, these abnormalities will become clearly detectable against the enhanced liver tissue on the MR image. This enhances the visualization and detection of focal liver lesions, including liver metastases.