CT artifacts from port systems: Virtual monoenergetic reconstructions from spectral-detector CT reduce artifacts and improve depiction of surrounding tissue

Kai Roman Laukamp; David Zopfs; Anton Wagner; Simon Lennartz; Lenhard Pennig; Jan Borggrefe; Nikhil Ramaiya; Nils Große Hokamp

doi:10.1016/j.ejrad.2019.108733

CT artifacts from port systems: Virtual monoenergetic reconstructions from spectral-detector CT reduce artifacts and improve depiction of surrounding tissue

Eur J Radiol. 2019 Dec:121:108733. doi: 10.1016/j.ejrad.2019.108733. Epub 2019 Nov 6.

Authors

Kai Roman Laukamp¹, David Zopfs², Anton Wagner², Simon Lennartz², Lenhard Pennig², Jan Borggrefe², Nikhil Ramaiya³, Nils Große Hokamp⁴

Affiliations

¹ Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Kerpener Straße 62, 50937, Cologne, Germany; Department of Radiology, University Hospitals Cleveland Medical Center, 11000 Euclid Ave, 44106 Cleveland, OH, USA; Department of Radiology, Case Western Reserve University, 10900 Euclid Ave, 44106, Cleveland, OH, USA. Electronic address: kai.laukamp@uk-koeln.de.
² Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Kerpener Straße 62, 50937, Cologne, Germany.
³ Department of Radiology, University Hospitals Cleveland Medical Center, 11000 Euclid Ave, 44106 Cleveland, OH, USA; Department of Radiology, Case Western Reserve University, 10900 Euclid Ave, 44106, Cleveland, OH, USA.
⁴ Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Kerpener Straße 62, 50937, Cologne, Germany; Department of Radiology, University Hospitals Cleveland Medical Center, 11000 Euclid Ave, 44106 Cleveland, OH, USA; Department of Radiology, Case Western Reserve University, 10900 Euclid Ave, 44106, Cleveland, OH, USA.

PMID: 31739270
DOI: 10.1016/j.ejrad.2019.108733

Abstract

Purpose: CT artifacts from port-systems are a common problem in staging- and restaging-examinations and reduce image quality and diagnostic assessment. The purpose of this study was to investigate the reduction of these artifacts using virtual monoenergetic images (VMI) from dual-energy spectral-detector CT (SDCT) in comparison to conventional CT-images (CI).

Method: 50 SDCT-datasets of patients with artifacts from port-chamber and port-catheters were included in this IRB-approved, retrospective study. CI and VMI (range, 40-200 keV, 10 keV increment) were reconstructed from the same acquisition. The quantitative image analysis was performed ROI-based assessing mean and standard deviation of attenuation (HU) in most pronounced hypo- and hyperdense artifacts surrounding to the port-chamber and the distal end of the port-catheter in the superior vena cava. Subjectively, artifact reduction and diagnostic assessment of surrounding soft tissue were rated on 5-point Likert-scales.

Results: In comparison to CI, VMI of higher keV-values showed strong reduction of hypo- and hyperattenuating artifacts around the port-chamber and port-catheter (CI/VMI_200keV: hypodense -104.7 ± 124.7HU/10.8 ± 58.1HU and -101.6 ± 101.5HU/-36.7 ± 32.9HU; hyperdense 240.8 ± 151.6HU/79.6 ± 81.3HU and 108.6 ± 129.3HU/25.9 ± 31.9HU; all p < 0.001). Image noise could also be reduced significantly. The subjective analysis showed significantly reduced artifacts around the port-chamber and port-catheter (CI/VMI_200keV: hypodense 3(1-4)/5(4-5) and 3(2-4)/5(4-5); hyperdense 3(1-4)/5(4-5) and 3(2-3)/5(3-5); all p < 0.001) and improved diagnostic assessment of pectoral/subclavian soft tissue for VMI of ≥100keV. Ratings for diagnostic assessment were best between 140-200 keV. Overall interrater agreement was high (ICC = 0.79).

Conclusions: Higher keV VMI enabled a significant reduction of artifacts from port-systems around the chamber and the catheter leading to improved assessment of surrounding soft tissue.

Keywords: Artifacts; Neoplasm staging; Port system; X-ray computed tomography.

Publication types

Review

MeSH terms

Adult
Artifacts*
Female
Humans
Image Processing, Computer-Assisted / methods*
Male
Middle Aged
Retrospective Studies
Signal-To-Noise Ratio
Tomography, X-Ray Computed / methods*
Vascular Access Devices*