Manganese chloride (Mn : 3mg/100g) aqueous solution with hydragenated oligosaccharide and xanthan gum (T_1 : 0.1sec, T_2 : 0.03sec at 0.5T) functions in gut as a positive contrast agent on MR T_1-weighted images and a low signal component on MR T_2-weighted images. The manganese in the solution functions as a contrast agent under free manganese ion (Mn^<2+>). Further, the solution has special characteristics in terms of MRI signal intensity and relaxation time that are equal to those of blueberry juice, which performs as an effective contrast agent on T_1-and T_2-weighted images, and functions as a contrast agent in vitro and in vivo.
