Figure 1: 18F labeled bile acid analogues under investigation in the present study. Compounds 3α-[18F]fluorocholic acid (3α-[18F]FCA), 3β-[18F]fluorochenodeoxycholic acid (3β-[18F]FCDCA), and 3β-[18F]fluoroglycocholic acid (3β-[18F]FGCA) on the upper row differ in bile acid structure (cholic acid, chenodeoxycholic acid, and glycocholic acid) or 3 α/β position of the radiolabel. The structures 12β-[18F]fluorocholic acid (12β-[18F]FCA) and 7β-[18F]fluorocholic acid (7β-[18F]FCA) have the same cholic acid structure, but different position of the radiolabel (7 or 12).