PoCGM: Poisson-Conditioned Generative Model for Sparse-View CT Reconstruction

TL;DR

PoCGM is a novel conditional generative model that improves sparse-view CT reconstruction by effectively reducing artifacts and preserving details, inspired by Poisson Flow models and tailored for medical imaging.

Contribution

It reformulates PFGM++ into a conditional framework for CT, enabling better artifact suppression and detail preservation in sparse-view reconstructions.

Findings

Outperforms baseline methods in artifact reduction

Enhances structural detail preservation

Demonstrates robustness in dose-sensitive scenarios

Abstract

In computed tomography (CT), reducing the number of projection views is an effective strategy to lower radiation exposure and/or improve temporal resolution. However, this often results in severe aliasing artifacts and loss of structural details in reconstructed images, posing significant challenges for clinical applications. Inspired by the success of the Poisson Flow Generative Model (PFGM++) in natural image generation, we propose a PoCGM (Poisson-Conditioned Generative Model) to address the challenges of sparse-view CT reconstruction. Since PFGM++ was originally designed for unconditional generation, it lacks direct applicability to medical imaging tasks that require integrating conditional inputs. To overcome this limitation, the PoCGM reformulates PFGM++ into a conditional generative framework by incorporating sparse-view data as guidance during both training and sampling phases. By modeling the posterior distribution of full-view reconstructions conditioned on sparse observations, PoCGM effectively suppresses artifacts while preserving fine structural details. Qualitative and quantitative evaluations demonstrate that PoCGM outperforms the baselines, achieving improved artifact suppression, enhanced detail preservation, and reliable performance in dose-sensitive and time-critical imaging scenarios.