SPADE: Spectroscopic Photoacoustic Denoising using an Analytical and Data-free Enhancement Framework

TL;DR

SPADE is a novel, tuning-free framework that enhances spectroscopic photoacoustic images by combining analytical and data-free methods, significantly improving noise reduction while preserving spectral information for clinical use.

Contribution

The paper introduces SPADE, a new denoising framework that does not require training data and maintains spectral fidelity, advancing real-time clinical spectroscopic photoacoustic imaging.

Findings

SPADE improves SNR in sPA images across various experiments.

SPADE outperforms traditional denoising methods in noise reduction.

SPADE preserves spectral linearity essential for functional imaging.

Abstract

Spectroscopic photoacoustic (sPA) imaging uses multiple wavelengths to differentiate chromophores based on their unique optical absorption spectra. This technique has been widely applied in areas such as vascular mapping, tumor detection, and therapeutic monitoring. However, sPA imaging is highly susceptible to noise, leading to poor signal-to-noise ratio (SNR) and compromised image quality. Traditional denoising techniques like frame averaging, though effective in improving SNR, can be impractical for dynamic imaging scenarios due to reduced frame rates. Advanced methods, including learning-based approaches and analytical algorithms, have demonstrated promise but often require extensive training data and parameter tuning, limiting their adaptability for real-time clinical use. In this work, we propose a sPA denoising using a tuning-free analytical and data-free enhancement (SPADE) framework for denoising sPA images. This framework integrates a data-free learning-based method with an efficient BM3D-based analytical approach while preserves spectral linearity, providing noise reduction and ensuring that functional information is maintained. The SPADE framework was validated through simulation, phantom, ex vivo, and in vivo experiments. Results demonstrated that SPADE improved SNR and preserved spectral information, outperforming conventional methods, especially in challenging imaging conditions. SPADE presents a promising solution for enhancing sPA imaging quality in clinical applications where noise reduction and spectral preservation are critical.