Validation of a low dose simulation technique for computed tomography images

PLoS One. 2014 Sep 23;9(9):e107843. doi: 10.1371/journal.pone.0107843. eCollection 2014.

Abstract

Purpose: Evaluation of a new software tool for generation of simulated low-dose computed tomography (CT) images from an original higher dose scan.

Materials and methods: Original CT scan data (100 mAs, 80 mAs, 60 mAs, 40 mAs, 20 mAs, 10 mAs; 100 kV) of a swine were acquired (approved by the regional governmental commission for animal protection). Simulations of CT acquisition with a lower dose (simulated 10-80 mAs) were calculated using a low-dose simulation algorithm. The simulations were compared to the originals of the same dose level with regard to density values and image noise. Four radiologists assessed the realistic visual appearance of the simulated images.

Results: Image characteristics of simulated low dose scans were similar to the originals. Mean overall discrepancy of image noise and CT values was -1.2% (range -9% to 3.2%) and -0.2% (range -8.2% to 3.2%), respectively, p>0.05. Confidence intervals of discrepancies ranged between 0.9-10.2 HU (noise) and 1.9-13.4 HU (CT values), without significant differences (p>0.05). Subjective observer evaluation of image appearance showed no visually detectable difference.

Conclusion: Simulated low dose images showed excellent agreement with the originals concerning image noise, CT density values, and subjective assessment of the visual appearance of the simulated images. An authentic low-dose simulation opens up opportunity with regard to staff education, protocol optimization and introduction of new techniques.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Female
  • Models, Animal
  • Radiation Dosage
  • Radiographic Image Interpretation, Computer-Assisted / methods*
  • Software Validation*
  • Swine
  • Tomography, X-Ray Computed / methods*

Grants and funding

This work is supported by Philips Healthcare. The funder provided support in the form of salaries for authors (TK, KB, SZ), but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript.