
Breast cancer remains one of the leading health concerns globally, making early detection essential for effective treatment. Traditional imaging methods, particularly mammography, have not always been effective across diverse populations, particularly for women with dense breast tissue and varying skin tones. Recent advancements in photoacoustic imaging offer a promising alternative, capable of enhancing visual clarity while addressing the significant challenge of skin tone bias in breast cancer detection.
Photoacoustic imaging is a cutting-edge technique that merges light and sound to generate detailed images of tissue. This method uses pulsed lasers to generate ultrasonic waves of light into breast tissue, where various structures, including cancerous cells, absorb it. This absorption generates acoustic waves, which are then detected to produce images. Unlike traditional imaging, photoacoustic imaging can penetrate deeper into the tissue, revealing more information about the structure and characteristics of breast tissue.
One of the significant revelations in recent studies, particularly one led by a team at Johns Hopkins University, is the skin tone bias associated with traditional imaging methods. Women with darker skin tones often face challenges in obtaining clear breast cancer screenings. The research highlighted that methods such as fast Fourier transform (FFT) and delay-and-sum (DAS) beamforming struggled to detect small cancerous targets, especially at certain wavelengths, affecting the reliability of diagnosis.
The study conducted by the Johns Hopkins team investigated three image reconstruction methods (FFT, DAS, and short-lag spatial coherence [SLSC] beamforming) across different wavelengths (757, 800, and 1064 nm) and varying skin tones. The results were telling: traditional methods struggled to visualize targets smaller than 3 mm, particularly under darker skin tones, at the 757 and 800 nm wavelengths. However, using the 1064 nm wavelength in combination with SLSC beamforming showed significant improvements in detecting small tumor targets.
This method enhanced visibility across all skin tones, providing clearer images with higher signal-to-noise ratios (SNR) and contrast-to-noise ratios (gCNR). The findings not only enhance the effectiveness of photoacoustic imaging but also underscore the importance of addressing skin tone bias in medical imaging technologies.
As researchers like senior and corresponding author Muyinatu Bell of this study have noted, a clearer understanding of photoacoustic imaging performance across various target sizes and skin tones significantly contributes to the development of next-generation imaging systems. This knowledge is vital for creating tools that are effective and accessible to varied populations, ensuring that every woman has the opportunity for early detection and timely intervention.
Sources:
https://www.sciencedirect.com/topics/medicine-and-dentistry/photoacoustic-imaging