Fig. 1. Catheter placement and indicator application site for cerebral blood flow measurements using the transcerebral double-indicator dilution technique. Ice-cold indocyanine green dye bolus injections into the right atrium (RA) were performed. For intravascular detection of the indicator kinetics, two combined fiberoptic thermistor catheters were placed in the thoracic aorta and the jugular bulb. The resulting thermo-/dye-dilution curves were measured simultaneously and stored digitally with a combined thermodilution and hemoreflectometer device.