Programmable scanning diffuse speckle contrast imaging of cerebral blood flow

Area of Science:

• Neuroimaging
• Biomedical Optics
• Cerebrovascular Research

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, continuous CBF monitoring solutions.

Purpose of the Study:

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

Main Methods:

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

Main Results:

• PS-DSCI successfully resolved intralipid particle flow contrasts at varying tissue depths.
• Demonstrated in vivo imaging of global and regional CBF variations in mice.
• Showcased capability to monitor CBF changes induced by hypoxia and carotid artery ligation.

Conclusions:

• PS-DSCI significantly enhances spatiotemporal resolution compared to conventional point scanning.
• The high sampling rate is crucial for capturing rapid CBF dynamics.
• High spatial resolution aids in visualizing brain vasculature, improving diagnostic potential.