Deep Guess acceleration for explainable image reconstruction in sparse-view CT.

Journal: Computerized medical imaging and graphics : the official journal of the Computerized Medical Imaging Society
Published Date:

Abstract

Sparse-view Computed Tomography (CT) is an emerging protocol designed to reduce X-ray dose radiation in medical imaging. Reconstructions based on the traditional Filtered Back Projection algorithm suffer from severe artifacts due to sparse data. In contrast, Model-Based Iterative Reconstruction (MBIR) algorithms, though better at mitigating noise through regularization, are too computationally costly for clinical use. This paper introduces a novel technique, denoted as the Deep Guess acceleration scheme, using a trained neural network both to quicken the regularized MBIR and to enhance the reconstruction accuracy. We integrate state-of-the-art deep learning tools to initialize a clever starting guess for a proximal algorithm solving a non-convex model and thus computing a (mathematically) interpretable solution image in a few iterations. Experimental results on real and synthetic CT images demonstrate the Deep Guess effectiveness in (very) sparse tomographic protocols, where it overcomes its mere variational counterpart and many data-driven approaches at the state of the art. We also consider a ground truth-free implementation and test the robustness of the proposed framework to noise.

Authors

  • Elena Loli Piccolomini
    Department of Computer Science and Engineering, University of Bologna, Italy. Electronic address: elena.loli@unibo.it.
  • Davide Evangelista
    Department of Mathematics, University of Bologna, Italy. Electronic address: davide.evangelista5@unibo.it.
  • Elena Morotti
    Department of Political and Social Sciences, University of Bologna, Italy. Electronic address: elena.morotti4@unibo.it.