Spatial-Temporal Oxygenation Mapping Using a Near-Infrared Optical Scanner: Towards Peripheral Vascular Imaging

Area of Science:

• Biomedical Engineering
• Physiology
• Medical Imaging

Background:

• Peripheral vascular dysfunction impacts microcirculation and tissue oxygenation.
• Near-infrared spectroscopy (NIRS) offers a non-invasive method to assess perfusion.
• Developing portable, cost-effective NIRS devices is crucial for clinical applications.

Purpose of the Study:

• To develop and validate a portable, non-contact near-infrared optical scanner (NIROS) for spatio-temporal mapping of tissue oxygenation.
• To assess NIROS's ability to measure real-time oxygenation changes in human subjects.
• To evaluate NIROS for feasibility in detecting microcirculatory differences in a mouse model of chronic kidney disease (CKD).

Main Methods:

• Developed a low-cost, portable, non-contact near-infrared optical scanner (NIROS).
• Conducted in vivo validation studies on control subjects (n=3) using an occlusion paradigm on the hand.
• Performed peripheral imaging in a mouse model (n=5) of CKD-induced vascular calcification, assessing tissue oxygenation changes in murine tails before and after calcification onset.

Main Results:

• NIROS demonstrated 95% correlation with a commercial device in capturing real-time tissue oxygenation changes.
• Distinct differences in tissue oxygenation (oxy-, deoxy-, total hemoglobin) were observed in murine tails before (week-6) and after (week-12) vascular calcification onset.
• The study successfully mapped spatio-temporal changes in tissue oxygenation.

Conclusions:

• NIROS is a validated, portable tool for assessing peripheral microcirculation and tissue oxygenation.
• NIROS can detect changes in microcirculatory oxygenation related to vascular dysfunction, such as in CKD.
• Further research will correlate peripheral oxygenation changes with cardiac vascular calcification in CKD models.