Carotid artery plaque characterization using CT multienergy imaging
L Saba1, G M Argiolas, P Siotto
1Department of Radiology, Azienda Ospedaliero Universitaria, di Cagliari-Polo di Monserrato, Monserrato, Cagliari, Italy. lucasaba@tiscali.it
Insights
Multi-energy CT imaging reveals that carotid artery plaque
Area of Science:
- Radiology
- Medical Imaging
- Cardiovascular Disease
Background:
- Carotid artery plaque characterization is crucial for stroke risk assessment.
- Hounsfield unit (HU) values are used to classify plaque types on CT scans.
- Multi-energy CT (MECT) offers advanced plaque analysis capabilities.
Purpose of the Study:
- To analyze carotid artery plaque characteristics using MECT.
- To investigate the impact of varying energy levels on plaque HU values.
Main Methods:
- Retrospective analysis of 64 carotid arteries from 32 patients using MECT.
- Contrast-enhanced imaging with a standardized protocol.
- Quantification of plaque HU values at monoenergetic levels of 66, 70, 77, and 86 keV.
Main Results:
- Significant differences in plaque HU values were observed across different keV levels (P=.0001).
- Increasing keV values led to a statistically significant reduction in plaque HU values.
- Exclusion of 11 arteries due to absence or heavy calcification of plaque.
Conclusions:
- Carotid artery plaque HU values are energy-dependent.
- Plaque classification based on HU values requires consideration of the applied kiloelectron volt (keV) level.
- MECT provides a more nuanced approach to plaque characterization.
Background And Purpose:
Carotid artery plaque types can be categorized with CT according to their HU values. The purpose of this work was to analyze carotid artery plaque characteristics by using multienergy imaging.
Methods And Materials:
Thirty-two consecutive patients (23 men; median age, 70 years) were retrospectively analyzed. Carotid arteries were studied with a multienergy CT scanner. All patients received a 15-mL timing bolus of contrast medium to synchronize the data acquisition followed by an injection of 60 mL of contrast medium at a 5-mL/s flow rate. Plaque analysis in 64 carotid arteries was performed, and datasets were reconstructed by using a dedicated workstation. For each plaque, the HU value was quantified with a 2-mm-square region of interest at monoenergy values of 66, 70, 77, and 86 keV. The Wilcoxon test was used to test the differences in HU values in the plaques at different kiloelectron volts.
Results:
Four carotid arteries were excluded due to the absence of plaque, and another 7, because of the presence of calcified plaques. In the remaining 53 carotid arteries, Wilcoxon analysis showed a statistically significant difference in HU values among the monoenergy values of 66, 70, 77, and 86 keV (P=.0001). In particular, we found that with the increase in monochromatic kiloelectron volt values, there is a statistically significant reduction in the HU value of the plaque.
Conclusions:
Results of this study suggest that the HU values of plaque may significantly change according to the selected kiloelectron volt; therefore, the HU-based plaque type (fatty, mixed, calcified) should be classified according to the energy level applied.
Related Concept Videos
01:25Imaging Studies for Cardiovascular System VI: Calcium -Scoring CT
01:28Imaging Studies for Cardiovascular System V: CT
01:21Imaging Studies for Cardiovascular System IV: CMRI