Quantitative contrast-enhanced ultrasound of intraplaque neovascularization in patients with carotid atherosclerosis.
OBJECTIVE
Intraplaque neovascularization (IPN) is an increasingly studied marker of the vulnerable atherosclerotic plaque, and contrast-enhanced ultrasound (CEUS) is an in vivo imaging technique for the assessment of IPN. The purpose of this study was to test novel quantification methods for the detection of carotid IPN using CEUS.


METHODS
25 patients with established carotid atherosclerosis underwent bilateral carotid CEUS using a Philips iU-22 ultrasound system with an L9 - 3 transducer. Visual scoring of IPN was performed using a 3-point score. Quantification of IPN was performed using novel custom developed software. In short, regions of interest were drawn over the atherosclerotic plaques. After motion compensation, several IPN features were calculated. Statistical analysis was performed using Spearman's rho. Reproducibility of the quantification features was calculated using intra-class correlation coefficients and mean differences between calculations.


RESULTS
45 carotid arteries were available for the quantification of IPN. The quantification of IPN was feasible in all 45 carotid plaques. The IPN area, IPN area ratio and neovessel count had a good correlation with the visual IPN score (respectively ρ = 0.719, ρ = 0.538, ρ = 0.474 all p < 0.01). The intra-observer and inter-observer agreement was good to excellent (p < 0.01). The intra-observer and inter-observer variability was low.


CONCLUSIONS
The quantification of carotid IPN on CEUS is feasible and provides multiple features on carotid IPN. Accurate quantitative assessment of IPN may be important to recognize and to monitor changes during therapy in vulnerable atherosclerotic plaques.
Cardiology, Erasmus Medical Center, Rotterdam, Netherlands.
S C H
SC
van den Oord
Biomedical Engineering, Erasmus Medical Center, Rotterdam, Netherlands.
Z
Z
Akkus
Biomedical Engineering, Erasmus Medical Center, Rotterdam, Netherlands.
J G
JG
Bosch
Biomedical Engineering, Israel Institute of Technology, Haifa, Israel.
A
A
Hoogi
Internal Medicine, Erasmus Medical Center, Rotterdam, Netherlands.
G L
GL
ten Kate
Biomedical Engineering, Erasmus Medical Center, Rotterdam, Netherlands.
G
G
Renaud
Internal Medicine, Erasmus Medical Center, Rotterdam, Netherlands.
E J G
EJ
Sijbrands
Vascular Surgery, Erasmus Medical Center, Rotterdam, Netherlands.
H J
HJ
Verhagen
Radiology, Erasmus Medical Center, Rotterdam, Netherlands.
A
A
van der Lugt
Biomedical Engineering, Israel Institute of Technology, Haifa, Israel.
D
D
Adam
Biomedical Engineering, Erasmus Medical Center, Rotterdam, Netherlands.
N
N
de Jong
Biomedical Engineering, Erasmus Medical Center, Rotterdam, Netherlands.
A F W
AF
van der Steen
Cardiology, Erasmus Medical Center, Rotterdam, Netherlands.
A F L
AF
Schinkel
D000368:Aged; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging*; D016893:Carotid Stenosis / Q000000981:diagnostic imaging*; D003287:Contrast Media; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007089:Image Enhancement; D007090:Image Interpretation, Computer-Assisted; D002546:Ischemic Attack, Transient / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D009389:Neovascularization, Pathologic / Q000000981:diagnostic imaging*; D012307:Risk Factors; D012984:Software; D014463:Ultrasonography
D003287:Contrast Media