Figure 6.

Tracers for assessing cardiac energy metabolism ¹⁸F-FDG is a glucose analog in which the oxygen in position C-2 is replaced with ¹⁸F. ¹⁸F-FDG is actively transported into the cell mediated by GLUT in the same way as glucose. Once inside the cell, glucose and ¹⁸F-FDG are phosphorylated by hexokinase. Phosphorylated glucose (G-6-P) continues along the glycolytic pathway for energy production. However, ¹⁸F-FDG-6-phosphate cannot enter glycolysis and is trapped intracellularly in a condition known as “metabolic trapping.” GLUT, glucose transporter; G-6-P, glucose-6-phosphate; FDG, ¹⁸F-fluorodeoxyglucose; FDG-6-P, ¹⁸F-FDG-6-phosphate