Understanding hepatocyte concentrations of compounds is a new translational topic. In the past, understanding compound distribution in the liver has been primarily made through the decrease of plasma concentrations. When conducting pharmacokinetic studies, it was assumed that liver concentrations approximate plasma concentrations. With the emerging knowledge of hepatocyte membrane transporters, it is clear that this assumption is no longer valid. Thus, depending on the relative influx and efflux clearances of compounds, hepatocyte concentrations can exceed, equal, or be lower than plasma concentrations. Disconnection between hepatocyte and plasma concentrations is even more unpredictable when expression and function of membrane transporters are altered during liver diseases.

With advances in liver imaging (PET, SPECT, and MRI), quantification of liver concentrations is now possible following the administration of hepatobiliary compounds. Using pharmacokinetic modeling, liver imaging can also predict the influx and efflux functions across hepatocyte transporters.

This special issue focuses on the understanding of liver imaging with hepatobiliary contrast media. We encourage the submission of original articles on basic, translational, and clinical studies, as well as reviews that describe topics linked to liver imaging with hepatobiliary contrast media.

Potential topics include but are not limited to the following:

• MRI, PET, and SPECT with hepatobiliary contrast agents in experimental and clinical studies
• Liver pharmacokinetics to understand the transport of contrast media across hepatocyte membranes and transporters
• Liver imaging to detect drug toxicity
• Hepatobiliary concentrations of compounds assessed with cell or organ imaging