Performance of acoustic radiation force impulse ultrasound imaging for carotid plaque characterization with histologic validation.

Abstract

OBJECTIVE:

Stroke is commonly caused by thromboembolic events originating from ruptured carotid plaque with vulnerable composition. This study assessed the performance of acoustic radiation force impulse (ARFI) imaging, a noninvasive ultrasound elasticity imaging method, for delineating the composition of human carotid plaque in vivo with histologic validation.

METHODS:

Carotid ARFI images were captured before surgery in 25 patients undergoing clinically indicated carotid endarterectomy. The surgical specimens were histologically processed with sectioning matched to the ultrasound imaging plane. Three radiologists, blinded to histology, evaluated parametric images of ARFI-induced peak displacement to identify plaque features such as necrotic core (NC), intraplaque hemorrhage (IPH), collagen (COL), calcium (CAL), and fibrous cap (FC) thickness. Reader performance was measured against the histologic standard using receiver operating characteristic curve analysis, linear regression, Spearman correlation (ρ), and Bland-Altman analysis.

RESULTS:

ARFI peak displacement was two-to-four-times larger in regions of NC and IPH relative to regions of COL or CAL. Readers detected soft plaque features (NC/IPH) with a median area under the curve of 0.887 (range, 0.867-0.924) and stiff plaque features (COL/CAL) with median area under the curve of 0.859 (range, 0.771-0.929). FC thickness measurements of two of the three readers correlated with histology (reader 1: R2 = 0.64, ρ = 0.81; reader 2: R2 = 0.89, ρ = 0.75).

CONCLUSIONS:

This study suggests that ARFI is capable of distinguishing soft from stiff atherosclerotic plaque components and delineating FC thickness.

• Authors: Tomasz J Czernuszewicz, Jonathon W Homeister, Melissa C Caughey, Yue Wang, Hongtu Zhu, Benjamin Y Huang, Ellie R Lee, Carlos A Zamora, Mark A Farber, Joseph J Fulton, Peter F Ford, William A Marston, Raghuveer Vallabhaneni, Timothy C Nichols, Caterina M Gallippi
• Journal: Journal of vascular surgery (J Vasc Surg) Vol. 66 Issue 6 Pg. 1749-1757.e3 (12 2017) ISSN: 1097-6809 [Electronic] United States
• PMID: 28711401 (Publication Type: Comparative Study, Journal Article, Validation Study)
• Copyright: Copyright © 2017 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

Chemical References

• Collagen
• Calcium

Topics

• Aged
• Area Under Curve
• Calcium (analysis)
• Carotid Arteries (chemistry, diagnostic imaging, pathology)
• Carotid Artery Diseases (diagnostic imaging, pathology)
• Collagen (analysis)
• Elasticity Imaging Techniques
• Female
• Fibrosis
• Hemorrhage (diagnostic imaging, pathology)
• Humans
• Male
• Middle Aged
• Necrosis
• Observer Variation
• Pilot Projects
• Plaque, Atherosclerotic
• Predictive Value of Tests
• Prognosis
• Prospective Studies
• ROC Curve
• Reproducibility of Results
• Vascular Calcification (diagnostic imaging, pathology)