Imaging lipid synthesis in XXXX with [methyl-11c]choline: correlation with in vivo metabolic studies.

@entity5 @entity5462 @entity1711 @entity25249 @entity2434 @entity6624 @entity1877 @entity1391 @entity1710 @entity3633 @entity13667 @entity7727 @entity157 @entity2945
PET with [methyl-(11)C]-choline ( @entity25249 ) can be useful for detecting well-differentiated @entity157 ( @entity157 ) that is not 18F-FDG-avid. This study was designed to examine the relationship between @entity1877 metabolism and @entity1877 tracer uptake in @entity157 for PET with @entity25249 . METHODS: Dynamic PET scans of @entity25249 were acquired using the woodchuck models of @entity157 . After imaging, [methyl-(14)C]-choline was injected, and metabolites from both @entity157 tissue samples and the surrounding hepatic tissues were extracted and analyzed by radio-high-performance liquid chromatography. The enzymatic activities of @entity1877 kinase and @entity1877 - @entity1391 cytidylyltransferase were assayed for correlation with the imaging and metabolism data. RESULTS: PET with @entity25249 showed an @entity157 detection rate of 9 of 10. The @entity5 -to-liver ratio for the 9 detected @entity5462 was 1.89  0.55. @entity1710 - @entity1711 staining confirmed that all spots with high tracer uptake were well-differentiated @entity5462 . Variation of radioactivity distribution within @entity5462 indicated a heterogeneous uptake of @entity1877 . The activities of both @entity1877 kinase and @entity2945 cytidylyltransferase were found to be significantly higher in @entity157 than in the surrounding hepatic tissues. The major metabolites of @entity25249 were @entity2945 in @entity157 and @entity7727 and @entity1877 in the surrounding hepatic tissues at 12 min after injection; in @entity157 , @entity2945 rapidly converted to @entity2434 at 30 min after injection. CONCLUSION: @entity5462 display enhanced uptake of radiolabeled @entity1877 despite a moderate degree of physiologic uptake in the surrounding hepatic tissues. Initially, increased radiolabeled @entity1877 uptake in @entity5462 is associated with the transport and phosphorylation of @entity1877 ; as time passes, the increased uptake of radiolabeled @entity1877 reflects increased @entity2434 synthesis derived from radiolabeled @entity6624 ( @entity13667 - @entity1877 ) in @entity5462 . In contrast, the surrounding hepatic tissues exhibit extensive oxidation of radiolabeled @entity1877 via the @entity3633 methylation pathway, a major contributor to the observed physiologic uptake.
