Virtual mono-energetic images and iterative image reconstruction: abdominal vessel imaging in the era of spectral detector CT

Y Al-Baldawi; N Große Hokamp; S Haneder; S Steinhauser; M Püsken; T Persigehl; D Maintz; C Wybranski

doi:10.1016/j.crad.2020.03.036

Virtual mono-energetic images and iterative image reconstruction: abdominal vessel imaging in the era of spectral detector CT

Clin Radiol. 2020 Aug;75(8):641.e9-641.e18. doi: 10.1016/j.crad.2020.03.036. Epub 2020 Apr 30.

Authors

Y Al-Baldawi¹, N Große Hokamp², S Haneder², S Steinhauser³, M Püsken², T Persigehl², D Maintz², C Wybranski²

Affiliations

¹ University of Cologne, Faculty of Medicine and University Hospital Cologne, Department of Diagnostic and Interventional Radiology, Cologne, Germany. Electronic address: [email protected].
² University of Cologne, Faculty of Medicine and University Hospital Cologne, Department of Diagnostic and Interventional Radiology, Cologne, Germany.
³ University of Cologne, Faculty of Medicine and University Hospital Cologne, Institute for Medical Statistics and Computational Biology, Cologne, Germany.

PMID: 32362502
DOI: 10.1016/j.crad.2020.03.036

Abstract

Aim: To compare the quality of virtual mono-energetic (VMI) and polychromatic images reconstructed with hybrid iterative (PCI_HIR) or model-based reconstruction (PCI_MBR) derived from dual-layer spectral detector computed tomography (SDCT) in arterial phase images to visualise the aorta and abdominal main branches.

Material and methods: A retrospective review of 50 patients with abdominal arterial phase scans was undertaken. Attenuation, intraluminal noise, and signal-/contrast-to-noise ratio (S-/CNR) were assessed in the PCI_HIR, PCI_MBR and VMI_40keV, VMI_70keV, and VMI_100keV images. Contrast, noise, and visualization of soft-plaque, and macro-/micro-calcifications were scored in a blinded reading by two radiologists.

Results: VMI_40keV yielded highest S-/CNR (p≤0.001). VMI_70keV and PCI_MBR showed comparable SNR (p≥0.999) and yielded higher SNR than PCI_HIR. VMI_70keV yielded higher CNR than PCI_HIR (p<0.001) and PCI_MBR (p<0.045). VMI_100keV yielded lowest CNR (p≤0.001) and SNR (p≥0.104). In the subjective analysis, VMI_40keV outperformed PCI_MBR for contrast and noise, PCI_MBR scored better than VMI_70keV, and the latter scored better than PCI_HIR for these categories (all p<0.001). PCI_MBR was superior for depiction of soft-plaque and micro-calcifications (p<0.001). VMI_100keV visualized micro-calcifications second best (p<0.001) and matched PCI_MBR for the depiction of macro-calcifications (p>0.999), while VMI_40keV scored second best for depiction of soft-plaque (p<0.020).

Conclusions: VMI_40keV and VMI_70keV yield better S-/CNR than PCI_HIR and PCI_MBR; however, PCI_MBR visualized arteriosclerotic plaques best, followed by VMI_40keV for depiction of soft-plaque and VMI_100keV for macro- and micro-calcification. Based on the present findings, PCI_MBR on conventional CT and VMI_40keV supplemented by VMI_100keV on SDCT are recommended for the diagnostic assessment of abdominal arteries.

MeSH terms

Aorta, Abdominal / diagnostic imaging*
Female
Humans
Image Processing, Computer-Assisted / methods*
Male
Mesenteric Arteries / diagnostic imaging*
Middle Aged
Renal Artery / diagnostic imaging*
Retrospective Studies
Tomography, X-Ray Computed / methods*
Vascular Diseases / diagnosis*
Virtual Reality*