Programmable scanning diffuse speckle contrast imaging of cerebral blood flow

Area of Science:

• Neuroimaging
• Biomedical Optics
• Cerebrovascular Physiology

Background:

• Cerebral blood flow (CBF) imaging is vital for diagnosing cerebrovascular diseases.
• Current neuroimaging techniques are costly, have low sampling rates, and lack mobility, hindering bedside monitoring.
• There is a need for accessible, portable, and high-resolution CBF imaging solutions.

Purpose of the Study:

• To develop a low-cost, portable, programmable scanning diffuse speckle contrast imaging (PS-DSCI) technology.
• To achieve fast, high-density, and depth-sensitive CBF imaging.
• To enable continuous and longitudinal CBF monitoring.

Main Methods:

• Utilized a programmable digital micromirror device (DMD) for remote line-shape laser scanning (785 nm).
• Synchronized a 2D camera for capturing diffuse laser speckle contrasts.
• Developed novel algorithms to correct for line-shape scanning deformations and minimize artifacts.

Main Results:

• PS-DSCI resolved Intralipid particle flow contrasts at varying tissue depths.
• Demonstrated in vivo imaging of global/regional CBF variations in mice.
• Successfully imaged CBF changes induced by CO2 inhalation and carotid artery ligation.

Conclusions:

• PS-DSCI significantly enhances spatiotemporal resolution compared to conventional point scanning.
• The high sampling rate and spatial resolution are critical for capturing rapid CBF changes and visualizing brain vasculature.
• PS-DSCI offers a promising solution for advanced CBF monitoring in research and clinical settings.