Single-View Fluorescence Molecular Tomography Based on Hyperspectral NIR-II Imaging

Biological tissue optics has garnered significant attention in biomedical research for its non-destructive, high-sensitivity nature. However, the scattering and absorption properties of biological tissues fundamentally limit the penetration depth of optical imaging. Fluorescence molecular tomography (FMT) offers a solution balancing imaging depth and resolution, yet tissue scattering and absorption continue to challenge depth-resolved reconstruction accuracy. This study develops a sensitive near-infrared II (NIR-II) hyperspectral imaging system to investigate the relationship between fluorescence penetration depth and tissue absorption/scattering coefficients. By leveraging the strong water absorption peak around 1450 nm, we strategically divide the reconstruction object into layers within the FMT model, significantly improving the ill-posed inverse problem. We then utilize hyperspectral data to select wavelengths with progressively decreasing absorption coefficients relative to the 1450 nm peak. This enables layer-by-layer 3D reconstruction of deep biological tissues, overcoming the limitations of conventional FMT. Our method demonstrates single-perspective FMT reconstruction capable of resolving heterogeneous targets at 10 mm depth with a 0.74 Dice coefficient in depth discrimination. This spectraldimension-enhanced FMT method enables accurate 3D reconstruction from single-view measurements. By exploiting the depth-dependent light-tissue interactions at selected NIR-II wavelengths, our approach achieves imaging quality comparable to multi-angle systems while simplifying the experimental setup. Both simulation and phantom experiments demonstrate precise target localization and shape recovery, suggesting promising potential for small animal imaging applications where system complexity and acquisition speed are critical.