Metabolic CEST MR imaging of glucosamine uptake in brain tumors

Motivation: The CEST signal of glucosamine (GlcN), a non-toxic food supplement was previously demonstrated in breast tumors and mouse brains. Goal(s): To investigate GlcN uptake and efficacy in detecting brain tumors. Approach: CEST MRI scans (7T) were performed in tumor-bearing mice (n=6) before and after GlcN injection. Data were analyzed using the magnetization transfer ratio asymmetry (MTRasym) metric. Results: Tumor regions presented signal enhancement compared to the contralateral tissue. The area under the MTRasym curve (1-2.2 ppm) was significantly higher at the tumor (P<0.05). Impact: This is the first study that examines the use of GlcN for brain tumor imaging. Given its low toxicity and transport capabilities across the blood-brain barrier (BBB), GlcN may be used as a nonmetallic contrast agent for evaluating brain malignancies.