Performance characterization of light-emitting diode array-based photoacoustic computed tomography (LED-PACT).

Area of Science:

• Biomedical Optics
• Medical Imaging
• Acoustic Imaging

Background:

• Photoacoustic computed tomography (PACT) typically relies on expensive pulsed laser diodes (PLDs).
• There is a need for more cost-effective and portable PACT systems for wider clinical adoption.
• Developing alternative light sources for PACT is crucial for advancing the field.

Purpose of the Study:

• To develop and evaluate a novel, cost-effective light-emitting diode-based PACT (LED-PACT) system.
• To compare the imaging performance of the LED-PACT system against traditional PLD-based PACT.
• To assess the feasibility of using a custom nanosecond pulsed LED array for PACT applications.

Main Methods:

• Integration of a 37-LED custom nanosecond pulsed LED array (850 nm, 100 ns pulse width) with a single-element ultrasound transducer for circular scanning.
• Driving the LED array using a homemade nanosecond pulsed current source (NSPCS) driver.
• Performance evaluation using phantom and chicken tissue studies, comparing imaging depth, resolution, and signal-to-noise ratio (SNR) against PLD-PACT.

Main Results:

• The LED-PACT system achieved a SNR of 22.4 dB (2.25 MHz UST) and a spatial resolution of 178 µm (5 MHz UST).
• A practical imaging depth of 20 mm was demonstrated in chicken tissue.
• The system operated at significantly lower optical energies (0.18 mJ) compared to PLD-PACT (1.88 mJ) while maintaining competitive performance.
• The total system cost was less than $1,000.

Conclusions:

• The developed LED-PACT system provides a cost-effective alternative to PLD-based PACT.
• The system demonstrates competitive imaging performance, including depth, resolution, and SNR.
• This LED-PACT technology holds significant potential for developing portable and widely accessible photoacoustic imaging devices for clinical translation.