Browsing by Author "Nicolaïdes, Andrew N."

Article

Ab Initio Calculations of the Barriers to Rotation in 1,1-Difluoroallyl Radical and an Analysis of the Factors That Govern Rotational Barriers in Fluorinated Allylic Radicals

Nicolaïdes, Andrew N.; Borden, W. T. (1992)

The energies required to rotate the CF2 and the CH2 group out of conjugation in 1,1-difluoroallyl radical have been calculated at the SD-CI/6–31G*//UHF/6–31G* level of theory. In agreement with experiment, the barrier to ...

Article

Ab Initio Calculations of the Relative Strengths of the π Bonds in Acetylene and Ethylene and of Their Effect on the Relative Energies of π-Bond Addition Reactions

Nicolaïdes, Andrew N.; Borden, W. T. (1991)

Energies at the CI-SD/6-31G* level have been calculated for acetylene, ethylene, ethane, and the vinyl and ethyl anions, radicals, and cations (classical and hydrogen-bridged). From these energies, the differences between ...

Conference Object

An AM-FM model for motion estimation in atherosclerotic plaque videos

Murray, V.; Murillo, S. E.; Pattichis, Marios S.; Loizou, Christos P.; Pattichis, Constantinos S.; Kyriacou, Efthyvoulos C.; Nicolaïdes, Andrew N. (2007)

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 ...

Conference Object

AM-FM representations for the characterization of carotid plaque ultrasound Images

Christodoulou, Christodoulos I.; Pattichis, Constantinos S.; Murray, V.; Pattichis, Marios S.; Nicolaïdes, Andrew N. (2008)

Stroke is the third leading cause of death in the western world and a major cause of disability in adults. The objective of this work was to investigate the use of AM-FM representations for the characterization of carotid ...

Article

AM-FM texture image analysis of the intima and media layers of the carotid artery

Loizou, Christos P.; Murray, V.; Pattichis, Marios S.; Christodoulou, C. S.; Pantzaris, Marios C.; Nicolaïdes, Andrew N.; Pattichis, Constantinos S. (2009)

The purpose of this paper is to propose the use of amplitude modulation-frequency modulation (AM-FM) features for describing atherosclerotic plaque features that are associated with clinical factors such as intima media ...

Book Chapter

Assessment of stroke by analysing carotid plaque morphology

Kyriacou, Efthyvoulos C.; Christodoulou, Christodoulos I.; Loizou, Christos P.; Pattichis, Marios S.; Pattichis, Constantinos S.; Kakkos, Stavros K.; Nicolaïdes, Andrew N. (IGI Global, 2009)

Stroke is the third leading cause of death in the Western world and a major cause of disability in adults. The objective of this work was to investigate morphological feature extraction techniques and the use of automatic ...

Article

Assessment of stroke risk based on morphological ultrasound image analysis with conformal prediction

Lambrou, Alexandra; Papadopoulos, Harris; Kyriacou, Efthyvoulos C.; Pattichis, Constantinos S.; Pattichis, Marios S.; Gammerman, A.; Nicolaïdes, Andrew N. (2010)

Non-invasive ultrasound imaging of carotid plaques allows for the development of plaque image analysis in order to assess the risk of stroke. In our work, we provide reliable confidence measures for the assessment of stroke ...

Conference Object

Atherosclerotic carotid plaque segmentation

Loizou, Christos P.; Pattichis, Constantinos S.; Istepanian, Robert Sh Habib; Pantzaris, Marios C.; Nicolaïdes, Andrew N. (2004)

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 ...

Conference Object

Atherosclerotic carotid plaque texture variability in ultrasound video

Loizou, Christos P.; Pantzaris, Marios C.; Nicolaïdes, Andrew N.; Pattichis, Constantinos S. (Springer Verlag, 2015)

Ultrasound video of the common carotid artery (CCA) combined with texture feature analysis has the potential in differentiating between asymptomatic and symptomatic atherosclerotic carotid plaque and is used widely for the ...

Conference Object

Atherosclerotic plaque motion analysis from ultrasound videos

Murillo, S. E.; Pattichis, Marios S.; Loizou, Christos P.; Pattichis, Constantinos S.; Kyriacou, Efthyvoulos C.; Constantinides, Anthony G.; Nicolaïdes, Andrew N. (2006)

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 ...

Article

CI Calculations on Didehydrobenzenes Predict Heats of Formation for the Meta and Para Isomers That Are Substantially Higher than Previous Experimental Values

Nicolaïdes, Andrew N.; Borden, W. T. (1993)

CI calculations with the 6-3110** basis set on o-didehydrobenzene (1) predict a singlet-triplet energy difference of 34.4 kcal/mol, which is about 3 kcal/mol smaller than the value measured by Leopold, Miller, and Lineberger. ...

Article

Classical and nonclassical isomers of tropylium, silatropylium, and germatropylium cations. Descending the periodic table increases the preference for nonclassical structures

Nicolaïdes, Andrew N.; Radom, L. (1997)

Ab initio calculations at the G2(MP2,SVP) level predict that there is a striking transition from a preference for classical isomers on the C7H7+ surface to a preference for nonclassical isomers on the C6H7Ge+ surface. The ...

Article

Classification of atherosclerotic carotid plaques using gray level morphological analysis on ultrasound images

Kyriacou, Efthyvoulos C.; Pattichis, Constantinos S.; Pattichis, Marios S.; Mavrommatis, A.; Panagiotou, S.; Christodoulou, Christodoulos I.; Kakkos, Stavros K.; Nicolaïdes, Andrew N. (2006)

The aim of this study was to investigate the usefulness of gray scale morphological analysis in the assessment of atherosclerotic carotid plagues. Ultrasound images were recorded from 137 asymptomatic and 137 symptomatic ...

Article

Classification of atherosclerotic carotid plaques using morphological analysis on ultrasound images

Kyriacou, Efthyvoulos C.; Pattichis, Marios S.; Pattichis, Constantinos S.; Mavrommatis, A.; Christodoulou, Christodoulos I.; Kakkos, Stavros K.; Nicolaïdes, Andrew N. (2009)

The aim of this study was to investigate the usefulness of multilevel binary and gray scale morphological analysis in the assessment of atherosclerotic carotid plaques. Ultrasound images were recorded from 137 asymptomatic ...

Article

Comparative evaluation of despeckle filtering in ultrasound imaging of the carotid artery

Loizou, Christos P.; Pattichis, Constantinos S.; Christodoulou, Christodoulos I.; Istepanian, Robert Sh Habib; Pantzaris, Marios C.; Nicolaïdes, Andrew N. (2005)

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 ...

Article

A comparative study of morphological and other texture features for the characterization of atherosclerotic carotid plaques

Christodoulou, Christodoulos I.; Kyriacou, Efthyvoulos C.; Pattichis, Marios S.; Pattichis, Constantinos S.; Nicolaïdes, Andrew N. (2003)

The extraction of features characterizing the structure of atherosclerotic carotid plaques, obtained by high-resolution ultrasound imaging is important for the correct plaque classification and the estimation of the risk ...

Conference Object

A comparison of ultrasound intima media thickness measurements of the left and right common carotid artery

Loizou, Christos P.; Pattichis, Constantinos S.; Georghiou, N.; Griffin, Maura B.; Nicolaïdes, Andrew N. (2013)

The intima-media thickness (IMT) of the common carotid artery (CCA) is an established indicator of cardiovascular disease (CVD). There have been reports about the difference between the left and the right sides of the CCA ...

Article

A Comparison of Ultrasound Intima-Media Thickness Measurements of the Left and Right Common Carotid Artery

Loizou, Christos P.; Nicolaïdes, Andrew N.; Kyriacou, Efthyvoulos C.; Georghiou, N.; Griffin, Maura B.; Pattichis, Constantinos S. (2015)

The intima-media thickness (IMT) of the common carotid artery (CCA) is an established indicator of cardiovascular disease (CVD). There have been reports about the difference between the left and the right sides of the CCA ...

Conference Object

Completely automated multiresolution edge snapper (CAMES): A new technique for an accurate carotid ultrasound IMT measurement and its validation on a multi-institutional database

Molinari, F.; Loizou, Christos P.; Zeng, G.; Pattichis, Constantinos S.; Pantzaris, Marios C.; Liboni, W.; Nicolaïdes, Andrew N.; Suri, J. S. (2011)

Since 2005, our research team has been developing automated techniques for carotid artery (CA) wall segmentation and intima-media thickness (IMT) measurement. We developed a snake-based technique (which we named CULEX 1,2), ...

Article

Completely automated multiresolution edge snapper-A new technique for an accurate carotid ultrasound IMT measurement: Clinical validation and benchmarking on a multi-institutional database

Molinari, F.; Pattichis, Constantinos S.; Zeng, G.; Saba, L.; Acharya, U. R.; Sanfilippo, R.; Nicolaïdes, Andrew N.; Suri, J. S. (2012)

The aim of this paper is to describe a novel and completely automated technique for carotid artery (CA) recognition, far (distal) wall segmentation, and intima-media thickness (IMT) measurement, which is a strong clinical ...