Blood oxygen saturation assessment in vivo using T2* estimation

Area of Science:

• Biomedical Engineering
• Medical Imaging
• Physiology

Background:

• Noninvasive assessment of blood oxygen saturation is crucial for clinical diagnosis.
• Existing methods for deep tissue oxygenation assessment have limitations.

Purpose of the Study:

• To investigate the feasibility of using blood T2* measurements for noninvasive oxygen saturation assessment in deep blood vessels.
• To develop and validate techniques for accurate blood T2* quantification in the presence of pulsatile flow.

Main Methods:

• Developed techniques for blood T2* measurements in arteries and veins, accounting for pulsatile flow using cardiac triggering.
• Validated the technique with a flow phantom and collected images at multiple echo times (TEs).
• Measured blood T2* in 10 volunteers and in a pig model with induced oxygen saturation changes.

Main Results:

• Arterial blood T2* (199 ± 8 ms) was significantly greater than venous blood T2* (108 ± 6 ms) in volunteers, correlating with oxygen saturation.
• In vivo experiments in pigs demonstrated a positive correlation between blood T2* and oxygen saturation levels.
• The proposed techniques successfully eliminated artifacts from pulsatile arterial blood flow.

Conclusions:

• Blood T2* measurement is a feasible method for noninvasively assessing local oxygen saturation in deep blood vessels.
• The developed techniques provide accurate T2* quantification, enabling differentiation of oxygen saturation between arterial and venous blood.
• This approach holds potential for improved clinical monitoring and diagnosis of conditions related to tissue oxygenation.