Indocyanine Green: Observations on Its Physical Properties, Plasma Decay, and Hepatic Extraction*

Indocyanine green 1 (ICG) is a tricarbocyanine dye (Figure Animal studies (3) and prelimi- nary observations of human subjects (4, 5) have suggested that this dye may have characteristics that could make its uptake, storage, and excretion by the liver helpful indices of hepatic function. The present investigations were carried out to determine whether indocyanine green has proper- ties that may render it suitable for assessing liver function and hepatic blood flow in man.