The paper tackles the inverse problem of recovering the initial pressure distribution in photoacoustic tomography (PAT) when nonlinear acoustic propagation and viscous attenuation are present. It models these effects with a nonlinear damped viscoelastic wave equation and proves well‑posedness of the forward problem. For the inverse problem, the authors establish existence, uniqueness, and local uniqueness results, and then propose a hybrid reconstruction framework that uses a convolutional neural network to generate an initial guess followed by a gradient‑free sequential quadratic Hamiltonian optimization to enforce the PDE dynamics. Numerical experiments show that this hybrid approach yields better reconstruction quality, contrast, and robustness than either time‑reversal or CNN‑only methods.
By Madhu Gupta, Anwesa Dey, Prapti Tala, Souvik Roy
Sparse-view computed tomography (CT) reduces radiation dose and acquisition time but remains severely ill-posed because incomplete projections poorly constrain null-space information. Existing learnin...
arXiv:2609.13688v1 Announce Type: cross
Abstract: Sparse-view computed tomography (CT) reduces radiation dose and acquisition time but remains severely ill-posed because incomplete projections poorly...
By Song Ni, Haijun Yu, Haodong Li, Changsheng Fang, Shuyi Fan, Yixing Huang, Hengyong Yu
arXiv:2505.08123v2 Announce Type: replace-cross
Abstract: Multi-material decomposition (MMD) enables quantitative reconstruction of tissue compositions in the human body, supporting a wide range of c...
By Qing Wu, Hongjiang Wei, Jingyi Yu, S. Kevin Zhou, Yuyao Zhang
PAGS is a new differentiable framework for blind autofocusing in photoacoustic computed tomography (PACT). It represents the initial pressure field with sparse Gaussian photoacoustic sources and models the speed‑of‑sound heterogeneity using a compact anisotropic path‑averaged field parameterized by spherical harmonics. By jointly optimizing the Gaussian source parameters and the speed‑of‑sound field in a closed‑loop signal‑domain approach, PAGS achieves sharper reconstructions in heterogeneous media, remains robust to sparse‑view sampling, and offers computational advantages through an analytic Gaussian acoustic projection.
By Jiarui Ge, Jintao Ma, Bangxu Fan, Jinyan Zhang, Xiaokang Yang, Shuai Na, Xiaoyun Yuan
Sparse-view spectral computed tomography (CT) reconstructs energy-resolved attenuation volumes from limited projection views, requiring simultaneous handling of angular undersampling and spectral coup...