A. N. Nicolaides

Learn More
It is well-known that speckle is a multiplicative noise that degrades the visual evaluation in ultrasound imaging. The recent advancements in ultrasound instrumentation and portable ultrasound devices necessitate the need of more robust despeckling techniques for enhanced ultrasound medical imaging for both routine clinical practice and teleconsultation.(More)
The intima-media thickness (IMT) of the common carotid artery (CCA) is widely used as an early indicator of the development of cardiovascular disease (CVD). It was proposed but not thoroughly investigated that the media layer (ML) thickness (MLT), its composition, and its texture may be indicative of cardiovascular risk and for differentiating between(More)
The objective of this article is to present an integrated system for the assessment of risk of stroke based on two modules: 1) clinical risk factors and noninvasive investigations, and 2) carotid plaque texture analysis. The system supports the data collected from the Asymptomatic Carotid Stenosis and Risk of Stroke (ACSRS) natural history study that(More)
The intima-media thickness (IMT) of the common carotid artery (CCA) is widely used as an early indicator of the development of cardiovascular disease (CVD). It was proposed but not thoroughly investigated that the media thickness (MT), its composition and texture may be indicative for identifying the risk of stroke and differentiating between patients with(More)
The extraction of multiple features from high-resolution ultrasound images of atherosclerotic carotid plaques, characterizing the plaque morphology and structure can be used for the classification and retrieval of similar plaques and the identification of individuals with asymptomatic carotid stenosis at risk of stroke. The objective of this work was to(More)
The objective of this work was to develop six speckle reduction-filtering techniques and evaluate them together with texture analysis in the assessment of 240 ultrasound images of the carotid artery. The despeckled filters are based on anisotropic diffusion, local statistics with higher moments, and geometric filtering. Results showed that some improvement(More)
Analysis of B-mode ultrasound images of the carotid atheromatous plaque includes the estimation of texture from static images and the estimation of motion from image sequences. The combination of these two types of information may be valuable for accurate diagnosis of vascular disease. The purpose of this paper was to study texture and motion patterns of(More)
In this paper, we describe a collection of algorithms that are used to provide motion trajectory estimates from atherosclerotic plaque ultrasound videos. Our approach is based on the use of four different optical flow methods to estimate motion vectors (Horn and Schunk, Lucas, Nagel and Uras). To estimate the optimal motion estimation parameters, we perform(More)
Atherosclerosis is the major cause of heart attack and stroke in the western world. In this paper we present a computerized method for segmenting the athrerosclerotic carotid plaque from ultrasound images. The method uses the blood flow image first to detect the initial contour of the plaque, and then despeckle filtering and snakes to deform the initial(More)
We present new multidimensional amplitude-modulation frequency-modulation (AM-FM) methods for motion estimation. For a single AM-FM component we show that the optical flow constraint leads to separate equations for amplitude modulation (AM) and frequency modulation (FM). We compare our approach with phase-based estimation developed by Fleet and Jepson and(More)