▎ 摘　　要

NOVELTY - Magnetic resonance contrast agent comprises MRI contrast agent having a hollow nanosphere structure, where the MRI contrast agent comprises 50-500 parts mass chitosan, 0.5-20 parts mass graphene oxide quantum dots and 10-500 parts mass contrast agent body. USE - Magnetic resonance contrast agent. ADVANTAGE - The resonance contrast agent solves the problems of low relaxation rate, high toxicity and short retention time of the existing MRI contrast agent. The method is simple to operate, safe and environmentally-friendly. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a method for preparing the MRI contrast agent, involving (i) preparing solution (a) comprising a chitosan solution and an aqueous medium, (ii) preparing solution (b) comprising solution (a), graphene oxide quantum dots and contrast agent body, (iii) filtering solution (b) to obtain a filtered solid, (iv) re-dissolving the solid to obtain solution (c), and (v) filtering solution (c) to obtain a filtered solution as a finished product.