High-attenuation artifact reduction in breast tomosynthesis using a novel reconstruction algorithm

Eur J Radiol. 2019 Jul;116:21-26. doi: 10.1016/j.ejrad.2019.04.014. Epub 2019 Apr 23.

Abstract

Purpose: To assess the effect on reducing the out-of-plane artifacts from metal objects in breast tomosynthesis (BT) using a novel artifact-reducing reconstruction algorithm in specimen radiography.

Methods and materials: The study was approved by the Regional Ethical Review Board. BT images of 18 partial- and whole mastectomy specimens from women with breast cancer were acquired before and after a needle was inserted close to the lesion. The images were reconstructed using both a standard reconstruction algorithm, and a novel algorithm; the latter uses pre-segmentation to remove highly attenuating artifact-inducing objects from projection images before reconstruction. Images were separately reconstructed with and without segmentation, and combined into an artifact-reduced reconstruction. Standard and artifact-reduced BT-algorithms were compared visually and quantitatively using clinical images of mastectomy specimens and a physical anthropomorphic phantom. Six readers independently assessed the visibility of the lesion with and without artifact-reduction in a side-by-side comparison. A quantitative analysis was performed, comparing the signal-difference to background ratio (SDBR) and artifact spread function (ASF) between the two reconstruction methods.

Results: The magnitude of out-of-plane artifacts was clearly reduced with the novel reconstruction compared to BT-images without artifact reduction. Lesion masking by artifacts was largely averted; tumour visibility was comparable to standard BT images without a needle. In 76 ± 8% (standard deviation) of cases overall, readers could confidently state needle location. The same figure was 94 ± 6% for whole mastectomy cases, compared to 62 ± 17% for partial mastectomies. With metal artifact reduction, SDBR increased by 97% in the phantom, and by 69% in the mastectomies. The artifact spread function was substantially narrower.

Conclusion: Artifact reduction in BT using a novel reconstruction method enables qualitatively and quantitatively improved clinical use of BT when metal artifacts can be a limiting factor such as in tomosynthesis-guided biopsy.

Keywords: Artifact reduction; Breast imaging; Breast tomosynthesis; Image reconstruction; Mammography.

MeSH terms

  • Algorithms*
  • Artifacts*
  • Biopsy
  • Breast / diagnostic imaging
  • Breast / pathology
  • Breast Neoplasms / diagnostic imaging*
  • Breast Neoplasms / pathology
  • Female
  • Humans
  • Image Processing, Computer-Assisted / methods*
  • Mammography / methods*
  • Mastectomy
  • Metals

Substances

  • Metals