Related Experiment Video
Updated: May 5, 2026
How to Build a Laser Speckle Contrast Imaging LSCI System to Monitor Blood Flow
Published on: November 11, 2010
Time-Resolved Laser Speckle Contrast Imaging (TR-LSCI) of Cerebral Blood Flow Response to Intracranial Pressure
Faraneh Fathi1, Peiwen Zhang1, Mehrana Mohtasebi2
1Department of Biomedical Engineering, University of Kentucky, Lexington, Kentucky, USA.
Insights
A new time-resolved laser speckle contrast imaging (TR-LSCI) platform noninvasively measures cerebral blood flow (CBF) dynamics. This technology advances neurovascular monitoring and assessment of cerebral autoregulation (CA).
Area of Science:
- Neuroscience
- Biomedical Engineering
- Medical Imaging
Background:
- Cerebral autoregulation (CA) failure impacts brain injury, but current methods lack spatial and temporal resolution for microvascular dynamics.
- Existing techniques for measuring cerebral blood flow (CBF) are often indirect, spatially limited, or unable to capture real-time microvascular changes.
Purpose of the Study:
- Develop and validate a scalable, noncontact time-resolved laser speckle contrast imaging (TR-LSCI) platform.
- Enable depth-sensitive, high-speed, wide-field CBF imaging for assessing CA during controlled intracranial pressure (ICP) changes.
Main Methods:
- TR-LSCI synchronizes a pulsed laser with a time-gated SPAD camera for depth-resolved CBF imaging.
- Systems were tested in rats and piglets, with simultaneous invasive ICP and arterial blood pressure (ABP) monitoring.
Main Results:
- TR-LSCI achieved high-speed (up to 52 Hz) imaging of heterogeneous, pulsatile CBF over large cortical areas.
- Analysis revealed distinct CA states (autoregulation, compensation, suppression) and phase-dependent CBF signatures.
Conclusions:
- TR-LSCI provides dynamic, physiology-informed neurovascular monitoring.
- This technology supports future bedside assessment of cerebral autoregulation.
Significance:
Cerebral autoregulation (CA) reflects the dynamic coupling among cerebral blood flow (CBF), intracranial pressure (ICP), and arterial blood pressure (ABP); its failure contributes to secondary brain injury. Existing bedside methods rely on indirect or spatially limited CBF surrogates and cannot resolve microvascular flow dynamics across space, depth, and time.
Aim:
To develop, optimize, and apply a scalable, noncontact time-resolved laser speckle contrast imaging (TR-LSCI) platform for depth-sensitive, high-speed, wide-field CBF imaging during controlled ICP perturbations.
Approach:
TR-LSCI synchronizes a 20-MHz pulsed laser with a time-gated, single-photon avalanche diode (SPAD) camera (512 × 512 pixels) to detect diffuse photons at varying path lengths, enabling depth-resolved microvascular CBF imaging. Benchtop and mobile TR-LSCI systems were applied in adult rats and a neonatal piglet with synchronized invasive ICP and ABP measurements.
Results:
TR-LSCI captured spatially heterogeneous, pulsatile CBF dynamics at up to 52 Hz over large cortical fields of view, with heart rate estimates statistically equivalent to those from ICP and ABP. Multivariable analysis identified reproducible, phase-dependent CA transitions encompassing preserved autoregulation, ABP-driven compensation, and ICP-constrained CBF suppression; notably, CBF alone exhibited distinct phase signatures.
Conclusions:
TR-LSCI enables dynamic, physiology-informed neurovascular monitoring and supports future bedside CA assessment.
More Related Videos
07:20A Novel Approach to Overcome Movement Artifact When Using a Laser Speckle Contrast Imaging System for Alternating Speeds of Blood Microcirculation
Published on: August 30, 2017
06:24Paired Cisterna Magna Nanoinjection and Laser Speckle Contrast Imaging Assay to Study Cerebral Blood Flow Regulation In Vivo
Published on: July 8, 2025
Related Concept Videos
01:14Increased Intracranial Pressure l: Introduction
01:29Increased Intracranial Pressure ll: Pathophysiology