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Updated: Feb 3, 2026

Advanced Animal Model of Colorectal Metastasis in Liver: Imaging Techniques and Properties of Metastatic Clones
Published on: November 30, 2016
Virtual Monoenergetic Images for Diagnostic Assessment of Hypodense Lesions Within the Liver: Semiautomatic
Nils Große Hokamp, Verena C Obmann, Rivka Kessner
1Institute for Diagnostic and Interventional Radiology, University Hospital Cologne, Cologne, Germany.
Objective:
The aim of the study was to establish the reference window settings for display of virtual monoenergetic images (VMIs) from spectral detector computed tomography when assessing hypodense liver lesions.
Methods:
In patients with cysts (n = 24) or metastases (n = 26), objective (HU, signal-to-noise ratio [SNR]) and subjective (overall image quality, lesion conspicuity and noise) were assessed. Furthermore, 2 readers determined optimal window center/width (C/W) for conventional images (CIs) and VMIs of 40 to 120 keV. Center/width were modeled against HUliv with and without respect to the keV level (models A and B).
Results:
Attenuation and SNR were significantly higher in low-keV VMIs and improved overall image quality and lesion conspicuity (P ≤ 0.05). Model B provided valid estimations of C/W, whereas model A was slightly less accurate.
Conclusions:
The increase in attenuation and SNR on low-keV VMIs requires adjustment of C/W, and they can be estimated in dependency of HUliv using linear models. Reference values for standard display of VMIs of 40 to 120 keV are reported.
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