Functional Molecular Imaging of Tumors by Chemical Exchange Saturation Transfer MRI of 3-O-Methyl-D-Glucose

PurposeTo evaluate the feasibility to detect tumors and metastases by the chemical exchange saturation transfer (CEST) MRI technique using 3-O-Methyl-D-glucose (3OMG), a nonmetabolizable derivative of glucose that is taken up rapidly and preferentially by tumors and is entirely excreted by the kidneys. MethodsIn vivo CEST MRI experiments were performed on a Bruker 7 Tesla Biospec on implanted orthotopic mammary tumors of mice before and following i.p. injection of 3OMG. The CEST images were generated by a series of gradient-echo images collected from a single 1 mm coronal slice after a 1.2 s presaturation pulse, applied at offsets of 1.2 ppm from the water and at B-1 power of 2.5 mu T. ResultsFollowing 3OMG (1.5 g/kg) i.p. injection, an enhanced CEST effect of approximately 20% was visualized at the tumor within a few minutes. The signal slowly declined reaching half of its maximum at approximately 80 min. ConclusionDue to the large CEST effect of 3OMG and its low toxicity 3OMG-CEST may serve for the detection of tumors and metastases in the clinic. Magn Reson Med 72:1375-1380, 2014. (c) 2014 Wiley Periodicals, Inc.