Light-emitting diode-based multiwavelength diffuse optical tomography system guided by ultrasound.

Area of Science:

• Biomedical optics
• Medical imaging technology
• Optical physics

Background:

• Laser diodes in diffuse optical tomography (DOT) are expensive and fragile.
• Light-emitting diodes (LEDs) offer a cost-effective alternative with adequate near-infrared (NIR) output for deep tissue imaging.

Purpose of the Study:

• To develop and evaluate a novel, low-cost DOT system utilizing NIR LEDs as light sources.
• To compare the performance of the LED-based DOT system against a traditional frequency-domain (FD) laser-diode system.

Main Methods:

• A handheld DOT probe equipped with four NIR LEDs modulated at 20 kHz.
• Integration of a printed circuit board for individual LED control.
• Coupling of reflected light via optical fibers to photomultiplier tube detectors.
• Ultrasound guidance for simultaneous target localization and image reconstruction.

Main Results:

• The LED-based DOT system demonstrated comparable quantification accuracy to the FD laser-diode system in phantom studies.
• The system successfully imaged embedded absorbers in intralipid and inhomogeneous tissue phantoms.
• The potential for imaging deep targets, such as breast lesions, was highlighted.

Conclusions:

• A low-cost, LED-based DOT system provides a viable alternative to expensive laser diode systems.
• The developed system shows promise for accessible deep tissue imaging applications.
• Ultrasound guidance enhances the accuracy and utility of LED-based DOT.