Image quality evaluation of dual-layer spectral detector CT of the chest and comparison with conventional CT imaging

Jonas Doerner; Myriam Hauger; Tilman Hickethier; Jonathan Byrtus; Christian Wybranski; Nils Große Hokamp; David Maintz; Stefan Haneder

doi:10.1016/j.ejrad.2017.05.016

Image quality evaluation of dual-layer spectral detector CT of the chest and comparison with conventional CT imaging

Eur J Radiol. 2017 Aug:93:52-58. doi: 10.1016/j.ejrad.2017.05.016. Epub 2017 May 20.

Authors

Jonas Doerner¹, Myriam Hauger², Tilman Hickethier², Jonathan Byrtus², Christian Wybranski², Nils Große Hokamp², David Maintz², Stefan Haneder²

Affiliations

¹ Department of Diagnostic and Interventional Radiology, University Hospital of Cologne, Cologne, Germany. Electronic address: jonas.doerner@uk-koeln.de.
² Department of Diagnostic and Interventional Radiology, University Hospital of Cologne, Cologne, Germany.

PMID: 28668431
DOI: 10.1016/j.ejrad.2017.05.016

Abstract

Objectives: To evaluate image quality parameters of virtual mono-energetic (MonoE) and conventional (CR) imaging derived from a dual-layer spectral detector CT (DLCT) in oncological follow-up venous phase imaging of the chest and comparison with conventional multi-detector CT (CR_MDCT) imaging.

Materials and methods: A total of 55 patients who had oncologic staging with conventional CT and DLCT of the chest in venous phase were included in this study. Established image quality parameters were derived from all datasets in defined thoracic landmarks. Attenuation, image noise, and signal-/contrast- to noise ratios (SNR, CNR) were compared between CR_DLCT and MonoE as well as CR_MDCT imaging. Two readers performed subjective image analysis.

Results: CR_MDCT showed significant lower attenuation values compared to CR_DLCT and MonoE at 40-70keV (p≤0.05). Moreover, MonoE at 40-70keV revealed significantly higher attenuations values compared to CR_DLCT (p<0.001). Noise was statistically lower in CR_MDCT compared with CR_DLCT and MonoE at 40keV (11.4±2.3 HU vs. 12.0±3.1 HU vs. 11.7±5.2 HU; p<0.001). In contrast, all MonoE levels showed significantly lower noise levels compared to CR_DLCT (p<0.001). SNR was not significantly different between CR_MDCT and CR_DLCT (13.5±3.7 vs. 14.4±5.3; p>0.99). SNR values were significantly increased for MonoE at 40-80keV compared to CR_MDCT and CR_DLCT (p<0.001). CR_DLCT and MonoE (40-70keV) from DLCT revealed significantly higher CNR values than CR_MDCT (p<0.001). In subjective analysis, MonoE at 40keV surpassed all other image reconstructions except for noise in MonoE at 70 keV.

Conclusion: In dual-layer spectral detector CT, MonoE at low keV showed superior image quality compared to conventional images derived from the same system and may therefore be added to clinical routine imaging protocols. Whether MonoE reconstructions yield additional diagnostic information is still unknown.

Keywords: Chest; Dual-layer detector CT; Spectral detector CT; Virtual mono-energetic imaging.

Publication types

Comparative Study

MeSH terms

Contrast Media
Female
Humans
Image Processing, Computer-Assisted / methods*
Male
Middle Aged
Radiographic Image Enhancement / methods
Radiography, Thoracic / methods*
Retrospective Studies
Signal-To-Noise Ratio
Thoracic Neoplasms / diagnostic imaging*
Tomography, X-Ray Computed / instrumentation*
Tomography, X-Ray Computed / methods*

Substances

Contrast Media