Variation of degree of stenosis quantification using different energy level with dual energy CT scanner
To investigate the variation in the quantification of the carotid degree of stenosis (DoS) with a dual energy computed tomography (CT), using different energy levels during the image reconstruction.
In this retrospective study, 53 subjects (37 males; mean age 67 ± 11 years; age range 47–83 years) studied with a multi-energy CT scanner were included. Datasets were reconstructed on a dedicated workstation and from the CT raw data multiple datasets were generated at the following monochromatic energy levels: 66, 70, 77, and 86 kilo-electronvolt (keV). Two radiologists independently performed all measurements for quantification of the degree of stenosis. Wilcoxon test was used to test the differences between the Hounsifield unit (HU) values in the plaques at different keV.
The Wilcoxon analysis showed a statistically significant difference (p = 0.001) in the DoS assessment among the different keVs selected. The Bland-Altman analysis showed that the DoS difference had a linear relation with the keV difference (the bigger is the difference in keV, the bigger is the variation in DoS) and that for different keVs, the difference in DoS is reduced with its increase.
A standardization in the use of the energy level during the image reconstruction should be considered.
KeywordsCT Dual energy CT Carotid artery
Compliance with ethical standards
No funding was received for this study.
Conflict of interest
The authors declare that they have no conflict of interest.
All procedures performed in the studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
Informed consent was obtained from all individual participants included in the study.
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