Are quantitative features of lung nodules reproducible at different CT acquisition and reconstruction parameters?

PLoS One. 2020 Oct 15;15(10):e0240184. doi: 10.1371/journal.pone.0240184. eCollection 2020.

Abstract

Consistency and duplicability in Computed Tomography (CT) output is essential to quantitative imaging for lung cancer detection and monitoring. This study of CT-detected lung nodules investigated the reproducibility of volume-, density-, and texture-based features (outcome variables) over routine ranges of radiation dose, reconstruction kernel, and slice thickness. CT raw data of 23 nodules were reconstructed using 320 acquisition/reconstruction conditions (combinations of 4 doses, 10 kernels, and 8 thicknesses). Scans at 12.5%, 25%, and 50% of protocol dose were simulated; reduced-dose and full-dose data were reconstructed using conventional filtered back-projection and iterative-reconstruction kernels at a range of thicknesses (0.6-5.0 mm). Full-dose/B50f kernel reconstructions underwent expert segmentation for reference Region-Of-Interest (ROI) and nodule volume per thickness; each ROI was applied to 40 corresponding images (combinations of 4 doses and 10 kernels). Typical texture analysis metrics (including 5 histogram features, 13 Gray Level Co-occurrence Matrix, 5 Run Length Matrix, 2 Neighboring Gray-Level Dependence Matrix, and 3 Neighborhood Gray-Tone Difference Matrix) were computed per ROI. Reconstruction conditions resulting in no significant change in volume, density, or texture metrics were identified as "compatible pairs" for a given outcome variable. Our results indicate that as thickness increases, volumetric reproducibility decreases, while reproducibility of histogram- and texture-based features across different acquisition and reconstruction parameters improves. To achieve concomitant reproducibility of volumetric and radiomic results across studies, balanced standardization of the imaging acquisition parameters is required.

Publication types

  • Evaluation Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Humans
  • Imaging, Three-Dimensional / methods*
  • Imaging, Three-Dimensional / standards
  • Multiple Pulmonary Nodules / diagnostic imaging*
  • Reproducibility of Results
  • Solitary Pulmonary Nodule / diagnostic imaging*
  • Tomography, X-Ray Computed / methods*
  • Tomography, X-Ray Computed / standards

Grants and funding

The research of BSE, MD, VG, LMP, and RDW was supported by the Edward J. DeBartolo, Jr. Family Fund (www.debartolofamilyfoundation.com) and the NIH Center for Accelerated Innovations (ncai.nhlbi.nih.gov/ncai). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Siemens Healthineers provided support in the form of salaries for authors TPO and RG but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of these authors are articulated in the ‘author contributions’ section.