Juxtaluminal hypoechoic area in ultrasonic images of carotid plaques and hemispheric symptoms

Griffin, Maura B. MSc, DIC, PhD
Kyriacou, Efthyvoulous BSc, PhD
Pattichis, Costas PhD
Bond, Dawn MA
Kakkos, Stavros K. MD, MSc, DIC, PhD
Sabetai, Michael MD, FRCS, PhD
Geroulakos, George MD, PhD
Georgiou, Niki RN
Doré, Caroline J. BSc
Nicolaides, Andrew MS, FRCS, PhD (Hon)

^aVascular Screening and Diagnostic Centre, London, United Kingdom
^bDepartment of Computer Science, University of Cyprus, Nicosia, Cyprus
^cDepartment of Vascular Surgery, Imperial College, London, United Kingdom
^dDepartment of Vascular Surgery, Ealing Hospital, London, United Kingdom
^eVascular Screening and Diagnostic Centre, Nicosia, Cyprus
^fMRC Clinical Trials Unit, London, United Kingdom
^gDepartment of Biological Sciences, University of Cyprus, Nicosia, Cyprus

Reprint requests: Maura B. Griffin, Vascular Screening and Diagnostic Centre, 28 Weymouth Street, London W1G 7BZ, UK. (e-mail: [email protected]).

This study was supported by a grant from the Cardiovascular Disease Educational and Research trust (CDER Trust), London, United Kingdom.

Competition of interest: Dr Nicolaides and Dr Kyriakou are consultants to Iconsoft International Ltd.

The editors and reviewers of this article have no relevant financial relationships to disclose per the JVS policy that requires reviewers to decline review of any manuscript for which they may have a competition of interest.

Submitted Oct 18, 2009; accepted Feb 23, 2010.

Journal of Vascular Surgery 52(1):p 69-76, July 2010.

Objectives:

The aim was to determine the diagnostic value of a juxtaluminal black (hypoechoic) area without a visible echogenic cap (JBA) in ultrasonic images of internal carotid artery plaques.

Methods:

Ultrasonic images of plaques from 324 patients with asymptomatic (n = 139) and symptomatic (n = 185) internal carotid 50% to 99% stenosis in relation to the bulb (European Carotid Surgery Trial) referred for duplex scanning were studied. The JBA in mm² and the gray-scale median (GSM) were obtained after image normalization. Cut-off points for GSM and JBA (combined highest sensitivity with highest specificity) were determined from receiver operator characteristic (ROC) curves.

Results:

JBA ≥ 8 mm² was associated with a high prevalence of symptomatic plaques in all grades of stenosis. In a multiple logistic regression model, increasing stenosis (mild, moderate, severe), GSM ≤ 15 and JBA ≥ 8 mm² were independent predictors of the presence of hemispheric symptoms. This model could identify a high-risk group of 188 plaques that contained 142 (77%) of the 185 symptomatic plaques (odds ratio [OR], 6.7; 95% confidence interval [CI], 4.08-10.91), (P< .001), (sensitivity: 77%; specificity 66%; positive predictive value 75%; negative predictive value 68%).

Conclusions:

The results of this study indicate the diagnostic value and for the first time suggest a cut-off point of 8 mm² for JBA. This cut-off point needs to be validated in other groups and then applied to prospective studies of asymptomatic patients.