Delay-and-sum-to-delay-standard-deviation factor: a promising adaptive beamformer.

Area of Science:

• Biomedical Optics
• Acoustic Imaging
• Image Reconstruction

Background:

• Minimum Variance (MV) beamforming improves spatial resolution in photoacoustic imaging (PAI) by narrowing main lobes.
• However, MV beamformers suffer from strong side-lobe signals, degrading reconstructed image contrast.
• Existing methods struggle to effectively suppress these side lobes without compromising image quality.

Purpose of the Study:

• To introduce a new adaptive weighting method, delay-and-sum-to-delay-standard-deviation factor (DASDSF), for PAI.
• To address the side-lobe signal issue in MV beamforming.
• To enhance image quality, signal-to-noise ratio (SNR), and enable cost-effective PAI systems.

Main Methods:

• Developed and integrated the DASDSF adaptive weighting method with MV beamforming.
• Evaluated the method using numerical simulations and experimental data from a home-built PAI system.
• Employed a low-cost, 16-element linear transducer array for validation.

Main Results:

• The DASDSF method significantly reduced side-lobe signal strength and improved image contrast compared to MV and MV-coherence factor beamformers.
• Achieved a notable improvement in SNR and a reduction in full-width at half-maximum (FWHM) of the main lobe.
• Demonstrated robustness against noise reduction.

Conclusions:

• The DASDSF weighting approach effectively mitigates side-lobe artifacts in PAI.
• The proposed method offers superior performance in SNR improvement, spatial resolution, and contrast enhancement.
• This technique holds promise for developing cost-effective PAI systems utilizing low-cost transducer arrays (e.g., 16 elements).