Tissue pulsatility imaging of cerebral vasoreactivity during hyperventilation.

Area of Science:

• Biomedical Engineering
• Medical Imaging
• Cardiovascular Physiology

Background:

• Tissue pulsatility imaging (TPI) is an emerging ultrasound technique.
• It measures tissue displacement and strain related to blood flow.
• TPI is based on principles of plethysmography.

Purpose of the Study:

• To evaluate the feasibility of TPI for assessing cerebral vasoreactivity.
• To determine if TPI can detect changes in cerebral blood flow during hyperventilation.

Main Methods:

• Ultrasound data were acquired transcranially using the temporal acoustic window.
• Four subjects underwent voluntary hyperventilation.
• Tissue pulsatility was measured before, during, and after hyperventilation.

Main Results:

• Decreases in tissue pulsatility were observed during hyperventilation.
• These decreases were statistically correlated with end-tidal CO2 measurements.
• This suggests TPI can detect physiological changes in cerebral blood flow.

Conclusions:

• Tissue pulsatility imaging is a feasible technique for assessing cerebral vasoreactivity.
• TPI shows potential for non-invasive monitoring of cerebrovascular function.
• Further research is warranted to validate TPI in clinical settings.