CT evaluation of coronary artery stents with iterative image reconstruction: improvements in image quality and potential for radiation dose reduction

Eur Radiol. 2013 Jan;23(1):125-32. doi: 10.1007/s00330-012-2580-5. Epub 2012 Jul 10.

Abstract

Objectives: Comparison of coronary artery stent assessment with cardiac CT angiography (cCTA) using traditional filtered back projection (FBP) and sinogram affirmed iterative reconstruction (SAFIRE), in both full- and half-radiation dose image data.

Methods: Dual-source cCTA studies of 37 implanted stents were reconstructed at full- and half-radiation dose with FBP and SAFIRE. Half-dose data were based on projections from one DSCT detector. In-stent noise, signal-to-noise ratio (SNR), and stent-lumen attenuation increase ratio (SAIR) were measured and image quality graded. Stent volumes were measured to gauge severity of beam hardening artefacts.

Results: Full-dose SAFIRE reconstructions were superior to full-dose FBP vis-à-vis in-stent noise (21.2 ± 6.6 vs. 35.7 ± 17.5; P < 0.05), SNR (22.1 ± 8.6 vs. 14.3 ± 6.7; P < 0.05), SAIR (19.6 ± 17.6 vs. 33.4 ± 20.4%; P < 0.05), and image quality (4.2 ± 0.86 vs. 3.5 ± 1.0; P < 0.05). Stent volumes were lower measured with SAFIRE (119.9 ± 53.7 vs. 129.8 ± 65.0 mm(3); P > 0.05). Comparing half-dose SAFIRE with full-dose FBP, in-stent noise (26.7 ± 13.0 vs. 35.7 ± 17.5; P < 0.05) and SNR (18.2 ± 6.9 vs. 14.3 ± 6.7; P < 0.05) improved significantly. SAIR (31.6 ± 24.3 vs. 33.4 ± 20.4%; P > 0.05), stent volume (129.6 ± 57.3 vs. 129.8 ± 65.0 mm(3); P > 0.05), and image quality (3.5 ± 1.0 vs. 3.7 ± 1.1; P > 0.05) did not differ. Radiation dose decreased from 8.7 ± 5.2 to 4.3 ± 2.6 mSv.

Conclusions: Iterative reconstruction significantly improves imaging of coronary artery stents by CT compared with FBP, even with half-radiation-dose data.

MeSH terms

  • Aged
  • Artifacts
  • Cardiac-Gated Imaging Techniques / methods*
  • Chi-Square Distribution
  • Comorbidity
  • Contrast Media
  • Coronary Angiography / methods*
  • Coronary Disease / diagnostic imaging*
  • Coronary Disease / surgery*
  • Female
  • Humans
  • Iohexol / analogs & derivatives
  • Male
  • Radiation Dosage*
  • Radiographic Image Interpretation, Computer-Assisted / methods*
  • Retrospective Studies
  • Signal-To-Noise Ratio
  • Statistics, Nonparametric
  • Stents*
  • Tomography, X-Ray Computed / methods*

Substances

  • Contrast Media
  • Iohexol
  • iopromide