Optical Attenuation‐Resistant Photoacoustic Tomography with Isotropic Contrast via Polarization‐Demodulated Magnetic Orientation Awareness

Abstract Optical imaging technologies, despite their transformative impact on biomedical science and clinical diagnostics, are constrained by the inevitable phenomenon of optical attenuation, leading to significant signal degradation and contrast distortion. Here, optical attenuation‐resisted photoacoustic tomography (OARPAT) by the aid of multiple polarization angles excitation and linear dichroism demodulation of magnetic alignment angle is proposed. This angle strategy separates the luminous flux decay from the image contrast and achieves depth‐resolved isotropic contrast imaging. Theoretical modeling demonstrates OARPAT with remarkable angular precision (σ = 1.64°) at signal‐to‐noise ratio of 12 dB and offers 49‐fold enhancement in contrast, compared to conventional photoacoustic imaging suffering from signal attenuation of 20 dB. Experimentally, OARPAT successfully achieves precise localization of organoids in chaotic scattering culture media at depths of up to 7.2 mm, avoiding missing target detection due to optical attenuation. In vivo studies, OARPAT enables tumor volume profile and growth cycle infiltration depth of 4.25 mm monitoring. It is anticipated that this work will serve as a powerful tool for precise visualization of deeper anatomical structures and organoid morphology and population behavior.