Design and implementation of a multifrequency near-infrared diffuse optical tomography system

Area of Science:

• Biomedical Optics
• Medical Imaging
• Optical Tomography

Background:

• Diffuse optical tomography (DOT) is a non-invasive imaging technique.
• Accurate reconstruction of absorption and scattering properties is crucial for DOT.
• Existing DOT systems can benefit from improved image quality and faster acquisition.

Purpose of the Study:

• To design and implement a multifrequency and multispectral diffuse optical tomography (DOT) system.
• To evaluate the performance of the developed DOT system using phantom studies.
• To demonstrate the superiority of multifrequency reconstruction for enhanced image quality.

Main Methods:

• Utilized four wavelengths (665, 785, 808, 830 nm) and six modulation frequencies (110-280 MHz).
• Employed a network analyzer for radio frequency (RF) modulation and signal measurement (amplitude and phase).
• Implemented a finite element method (FEM) for solving the diffusion equation and an inverse solver for image reconstruction.

Main Results:

• Achieved data acquisition in under 2.5 minutes per wavelength per modulation frequency.
• Demonstrated high measurement repeatability (0.5% in intensity, 0.2° in phase).
• Showcased superior image quality with the multifrequency reconstruction algorithm compared to single-frequency methods.

Conclusions:

• The developed multifrequency and multispectral DOT system offers efficient and repeatable measurements.
• Multifrequency reconstruction significantly enhances image quality in diffuse optical tomography.
• This system holds promise for advanced biomedical imaging applications.