▎ 摘　　要

NOVELTY - Method for producing a magnetic resonance imaging contrast agent involves (a) preparing a saccharide solution by adding carbon-13 (13C)-containing saccharides to an aqueous solution, (b) synthesizing 13C-containing graphene quantum dots by treating the saccharide solution with microwaves, and (c) preparing a magnetic resonance imaging contrast agent comprising 13C-containing graphene quantum dots. USE - The method is useful for producing magnetic resonance imaging contrast agent, which is used for obtaining and monitoring image of angiogenesis of blood vessels, lymph nodes, or cancer cells, or atherosclerosis plaques (all claimed), and diagnosing desired disease e.g. gastric cancer, lung cancer, breast cancer, liver cancer, laryngeal cancer, cervical cancer, ovarian cancer, bronchial cancer, nasopharyngeal cancer, pancreatic cancer, bladder cancer, or colon cancer. ADVANTAGE - The method is one-step method which mass-produces magnetic resonance imaging contrast agent in an easier, rapid and cost-effective manner without using harmful substances such as organic solvents, and thus avoids post-treatment process for subsequent removal. The agent has improved stability, increased solubility and low toxicity, is easily excreted from body, and reduces incidence of renal systemic fibrosis. The method enables to diagnose desired disease in a rapid and accurate manner with high sensitivity. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) magnetic resonance imaging contrast agent comprising 13C-containing graphene quantum dots as an active ingredient; and (2) method for monitoring image involves administering the magnetic resonance imaging contrast agent to the subject.