Transcranial Duplex Ultrasonography Measurements Towards Identification of Blood Vessel Conditions: Artificial Cerebral Blood Flow in Pathologies

The aim of the study was to investigate how cerebral vasospasm, vasodilation and haemorrhage under artificial circulation conditions during cardiopulmonary bypass affect transcranial duplex ultrasonography measurements. A description of transcranial duplex ultrasonography and phantom development is provided. Measurements were made using a commercially available ultrasound system and cardiopulmonary bypass machine, water phantom and 32% glycerol solution with cornstarch. The experiments showed that the cerebral blood vessel condition in artificial circulation affects transcranial duplex ultrasonography measurement limit values. The most sensitive parameter for blood vessel condition changes is Peak Systolic Velocity (PSV) for which changes were observed in 100% of cases. The most insensitive was Time-Averaged Peak-Velocity (TAPV), and Minimum Diastolic Velocity (MDV) for which changes were observed in 83% of cases.