Comparability of the ultrasonic tissue characteristics of carotid plaques

Hypoechoic carotid atherosclerotic plaques on ultrasonographic examination were found to be associated with cerebrovascular events. This underlines th e need for an accurate evaluation of their echotexture characteristics. The objective of this study was to further validate a proposed method of norma lization aiming to facilitate the comparability of these characteristics. The sonographic examination involved imaging of carotid plaques using duple x technique and capturing, digitization, and normalization in a computer in a standard way In the first part, the interobserver and interscanner varia bility and the gain-level variability within the ultrasound unit were exami ned, before and after normalization, in terms of plaque echotexture. The se cond part investigated the effect of normalization on the echotexture of 41 9 symptomatic and asymptomatic plaques. Our results indicated that the norm alization reduced the interscanner variability and the gain-level variabili ty. The interobserver variability) was excellent. In addition, this process further distinguished the echotexture characteristics of symptomatic and a symptomatic carotid plaques, which encourages the use of this method in nat ural history studies in persons with asymptomatic carotid atherosclerotic d isease, aiming to identify those at higher risk for stroke. These patients might benefit from a carotid endarterectomy.