Researchers at Saratov State University and their colleagues have developed an innovative approach to improving the visualization of subsurface blood vessels using laser speckle contrast imaging (LSCI) enhanced with principal component analysis (PCA). This revolutionary method overcomes significant limitations of traditional technologies, providing depth-independent blood flow assessments with unprecedented accuracy.
The team has created a unique technique that allows clear visualization of blood vessels located beneath the skin and other tissues without requiring invasive procedures. Based on LSCI and PCA, this approach enables precise imaging of blood flow at depths of up to 2 mm — a significant challenge for traditional methods.
Why does it matter?
This achievement is particularly important because traditional LSCI works well for visualizing superficial vessels and is widely used due to its affordability and simplicity. However, when vessels are hidden beneath tissue layers, the technology struggles. The new method overcomes these limitations while retaining all the advantages of traditional LSCI — simplicity, cost-effectiveness, and no need for equipment modification.
What has changed?
With the new approach, researchers have learned to "filter" signals, separating blood flow information from static background noise. This improves image clarity and enables accurate assessment of blood flow even in challenging conditions.
Key advantages:

• Depth is no longer an issue. The method performs consistently across all tissue layers.
• Increased sensitivity. Accurate visualization of blood flow velocities in the physiological range.
• Accessibility. No special or expensive equipment is required to use the new method.
• Versatility. The technology is suitable for diagnostics and treatments in fields such as neurosurgery, organ transplantation, and vascular diagnostics.

How was it tested?
The method was successfully tested on a laboratory rat. Results showed significant improvement in the clarity of vascular images compared to traditional approaches. These findings confirm the reliability and potential of the method for clinical use.
The ability to observe and monitor blood flow under complex conditions opens new horizons in neurosurgery, transplantation, and vascular pathology diagnostics. This method could become the standard for non-invasive visualization in biomedicine, enhancing the quality of diagnostics and treatments.

The work entitled “Laser speckle contrast imaging with principal component and entropy analysis: a novel approach for depth-independent blood flow assessment” was published on Frontiers of Optoelectronics (published on Jan. 3, 2025).
DOI: 10.1007/s12200-024-00143-1