Artifact removal using a hybrid-domain convolutional neural network for limited-angle computed tomography imaging

Phys Med Biol. 2020 Aug 5;65(15):155010. doi: 10.1088/1361-6560/ab9066.

Abstract

The suppression of streak artifacts in computed tomography with a limited-angle configuration is challenging. Conventional analytical algorithms, such as filtered backprojection (FBP), are not successful due to incomplete projection data. Moreover, model-based iterative total variation algorithms effectively reduce small streaks but do not work well at eliminating large streaks. In contrast, FBP mapping networks and deep-learning-based postprocessing networks are outstanding at removing large streak artifacts; however, these methods perform processing in separate domains, and the advantages of multiple deep learning algorithms operating in different domains have not been simultaneously explored. In this paper, we present a hybrid-domain convolutional neural network (hdNet) for the reduction of streak artifacts in limited-angle computed tomography. The network consists of three components: the first component is a convolutional neural network operating in the sinogram domain, the second is a domain transformation operation, and the last is a convolutional neural network operating in the CT image domain. After training the network, we can obtain artifact-suppressed CT images directly from the sinogram domain. Verification results based on numerical, experimental and clinical data confirm that the proposed method can significantly reduce serious artifacts.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Artifacts*
  • Humans
  • Image Processing, Computer-Assisted / methods*
  • Neural Networks, Computer*
  • Phantoms, Imaging
  • Tomography, X-Ray Computed*