Fig. 1.
The initial transmission scan sequence lasted 5 to 10 min, and then a paired session of [15O]H2O and [15O]O2 administration was conducted that lasted 20 min. Infusion of the study medication and the steady-state period lasted until the desired effect on blood pressure was achieved (15 min). Finally, another 20-min paired session of [15O]H2O and [15O]O2 administration ended the positron emission tomography examinations. Because it required approximately 65 min to complete the protocol, 45 min to anesthetize and prepare the patient, and 20 min to transport the patient, a total of approximately 130 min passed before the patient was ready for surgery. Another 20 min elapsed before the subdural intracranial pressure measurement.