Summary of the various PET and SPECT radiopharmaceuticals to assess myocardial substrate metabolism. FTHA, F-18 fluoro-6-thia-heptadecanoic acid. FCPHA, trans-9(RS)-18F-fluoro-3,4(RS,RS) methyleneheptadecanoic acid, BMIPP. 123I-beta-methyl-P iodophenylpentadecanoic acid HK, Hexokinase; PFK, phosphorfructokinase; ADP, adenosine diphosphate; TCA; tricarboxcylic acid cycle; PDH, pyruvate dehydrogenase; TG, triglyceride; G3PDH, glyceraldehyde 3-phosphate dehydrogenase;αGP, alpha-glycerol phosphate. Reproduced with permission from Herrero P, Gropler RJ. Imaging of myocardial metabolism. J Nucl Cardiol 2005;12(3):345–358.