Multispectral imaging of tissue absorption and scattering using spatial frequency domain imaging and a...

Area of Science:

• Biomedical Optics
• Medical Imaging
• Spectroscopy

Background:

• Accurate mapping of tissue optical properties is crucial for diagnosing and monitoring various medical conditions.
• Existing methods for measuring tissue absorption and scattering are often slow, require physical contact, or lack spatial resolution.

Purpose of the Study:

• To develop and validate a rapid, noncontact imaging approach for quantitative mapping of tissue absorption and scattering spectra.
• To combine multifrequency spatial frequency domain imaging (SFDI) with computed-tomography imaging spectrometry (CTIS) for enhanced performance.

Main Methods:

• The study utilized a novel system integrating SFDI with CTIS to project structured illumination patterns and capture spectral data simultaneously.
• The system acquired spatial-spectral data 30 times faster than conventional wavelength-scanning methods.
• Validation was performed using tissue-simulating phantoms across 36 wavelengths (650-1000 nm).

Main Results:

• The combined SFDI-CTIS system demonstrated rapid, multispectral imaging capabilities for tissue optical properties.
• Accurate measurements of absorption coefficients (μa) showed average errors <10% (650-800 nm) and <20% (800-1000 nm).
• Reduced scattering coefficients (μs') were measured with average errors <5% (650-700 nm) and <3% (700-1000 nm).

Conclusions:

• The SFDI-CTIS platform offers a significant advancement in noncontact, nonscanning optical imaging of biological tissues.
• This technology has potential applications in preclinical research, such as characterizing tissue changes in mouse models of brain injury.
• The rapid and quantitative nature of this method facilitates in vivo studies of tissue pathophysiology.