European Radiology

, Volume 20, Issue 3, pp 630–639

Evaluation of image quality and lesion perception by human readers on 3D CT colonography: comparison of standard and low radiation dose

  • Valeria A. Fisichella
  • Magnus Båth
  • Åse Allansdotter Johnsson
  • Fredrik Jäderling
  • Tommy Bergsten
  • Ulf Persson
  • Kristin Mellingen
  • Mikael Hellström
Gastrointestinal

DOI: 10.1007/s00330-009-1601-5

Cite this article as:
Fisichella, V.A., Båth, M., Allansdotter Johnsson, Å. et al. Eur Radiol (2010) 20: 630. doi:10.1007/s00330-009-1601-5

Abstract

Aims

We compared the prevalence of noise-related artefacts and lesion perception on three-dimensional (3D) CT colonography (CTC) at standard and low radiation doses.

Methods

Forty-eight patients underwent CTC (64 × 0.625 mm collimation; tube rotation time 0.5 s; automatic tube current modulation: standard dose 40–160 mA, low dose 10–50 mA). Low- and standard-dose acquisitions were performed in the supine position, one after the other. The presence of artefacts (cobblestone and snow artefacts, irregularly delineated folds) and the presence of polyps were evaluated by five radiologists on 3D images at standard dose, the original low dose and a modified low dose, i.e. after manipulation of opacity on 3D.

Results

The mean effective dose was 3.9 ± 1.3 mSv at standard dose and 1.03 ± 0.4 mSv at low dose. The number of images showing cobblestone artefacts and irregularly delineated folds at original and modified low doses was significantly higher than at standard dose (P < 0.0001). Most of the artefacts on modified low-dose images were mild. No significant difference in sensitivity between the dose levels was found for polyps ≥6 mm.

Conclusions

Reduction of the effective dose to 1 mSv significantly affects image quality on 3D CTC, but the perception of ≥6 mm lesions is not significantly impaired.

Keywords

CT colonographyRadiation exposureImage qualityThreedimensional CTColonic neoplasm

Copyright information

© European Society of Radiology 2009

Authors and Affiliations

  • Valeria A. Fisichella
    • 1
    • 2
  • Magnus Båth
    • 3
    • 4
  • Åse Allansdotter Johnsson
    • 1
    • 2
  • Fredrik Jäderling
    • 5
  • Tommy Bergsten
    • 6
  • Ulf Persson
    • 7
  • Kristin Mellingen
    • 8
  • Mikael Hellström
    • 1
    • 2
  1. 1.Department of RadiologySahlgrenska University HospitalGothenburgSweden
  2. 2.Sahlgrenska AcademyUniversity of GothenburgGothenburgSweden
  3. 3.Department of Medical Physics and Biomedical EngineeringSahlgrenska University HospitalGothenburgSweden
  4. 4.Department of Radiation PhysicsUniversity of GothenburgGothenburgSweden
  5. 5.Department of RadiologySt. Göran’s HospitalStockholmSweden
  6. 6.Department of RadiologyVästra Frölunda HospitalGothenburgSweden
  7. 7.Department of RadiologyLindesberg HospitalLindesbergSweden
  8. 8.Department of RadiologyUllevål University HospitalOsloNorway