CEST MRI of 3‐O‐methyl‐D‐glucose uptake and accumulation in brain tumors

Purpose 3‐O‐Methyl‐D‐glucose (3‐OMG) is a nonmetabolizable structural analog of glucose that offers potential to be used as a CEST‐contrast agent for tumor detection. Here, we explore it for CEST‐detection of malignant brain tumors and compare it with D‐glucose. Methods Glioma xenografts of a U87‐MG cell line were implanted in five mice. Dynamic 3‐OMG weighted images were collected using CEST‐MRI at 11.7 T at a single offset of 1.2 ppm, showing the effect of accumulation of the contrast agent in the tumor, following an intravenous injection of 3‐OMG (3 g/kg). Results Tumor regions showed higher enhancement as compared to contralateral brain. The CEST contrast enhancement in the tumor region ranged from 2.5‐5.0%, while it was 1.5‐3.5% in contralateral brain. Previous D‐glucose studies of the same tumor model showed an enhancement of 1.5‐3.0% and 0.5‐1.5% in tumor and contralateral brain, respectively. The signal gradually stabilized to a value that persisted for the length of the scan. Conclusions 3‐OMG shows a CEST contrast enhancement that is approximately twice as much as that of D‐glucose for a similar tumor line. In view of its suggested low toxicity and transport properties across the BBB, 3‐OMG provides an option to be used as a nonmetallic contrast agent for evaluating brain tumors.