Despeckle Filtering Algorithms and Software for Ultrasound Imaging

It is well-known that speckle is a multiplicative noise that degrades image quality and the visual evaluation in ultrasound imaging. This necessitates the need for robust despeckling techniques for both routine clinical practice and teleconsultation. The goal for this book is to introduce the theoretical background (equations), the algorithmic steps, and the MATLAB™ code for the following group of despeckle filters: linear filtering, nonlinear filtering, anisotropic diffusion filtering and wavelet filtering. The book proposes a comparative evaluation framework of these despeckle filters based on texture analysis, image quality evaluation metrics, and visual evaluation by medical experts, in the assessment of cardiovascular ultrasound images recorded from the carotid artery. The results of our work presented in this book, suggest that the linear local statistics filter DsFlsmv, gave the best performance, followed by the nonlinear geometric filter DsFgf4d, and the linear homogeneous maskarea filter DsFlsminsc. These filters improved the class separation between the asymptomatic and the symptomatic classes (of ultrasound images recorded from the carotid artery for the assessment of stroke) based on the statistics of the extracted texture features, gave only a marginal improvement in the classification success rate, and improved the visual assessment carried out by two medical experts. A despeckle filtering analysis and evaluation framework is proposed for selecting the most appropriate filter or filters for the images under investigation. These filters can be further developed and evaluated at a larger scale and in clinical practice in the automated image and video segmentation, texture analysis, and classification not only for medical ultrasound but for other modalities as well, such as synthetic aperture radar (SAR) images. Table of Contents: Introduction to Ultrasound Imaging / Despeckle Filtering Algorithms / Evaluation Methodology / Applications of Despeckle Filtering in Ultrasound Imaging / Comparison and Discussion of Despeckle Filtering Algorithms / Summary and Future Directions

Christos P. Loizou received his B.Sc. degree in electrical engineering, a Dipl-Ing (M.Sc.) degree in computer science and telecommunications from the University of Kaisserslautern, Kaisserslautern, Germany, and his Ph.D. degree on ultrasound image analysis of the carotid artery from the Department of Computer Science, Kingston University, London, UK, in 1986, 1990, and 2005, respectively. From 1996- 2000,he was a lecturer in the Department of Computer Science, Higher Technical Institute, Nicosia, Cyprus. Since 2000, he has been at the Department of Computer Science, Intercollege, Cyprus and is now a campus program coordinator. Since 2005, he has also been an Adjunct Professor of Medical Image and video processing, in the Department of Electrical Engineering, and Computer Engineering and Informatics, Cyprus University of Technology, Cyprus. He has also been an Associated Researcher at the Institute of Neurology and Genetics, Nicosia, Cyprus since 2000. Dr. Loizou was a supervisor of a number of Ph.D. and B.Sc. students in the area of computer image analysis and telemedicine. He was involved in the research activity of several scientific Cypriot and European research projects and has authored or co-authored 28 referred journals, 54 conference papers, 3 books, and 10 book chapters in the fields of image and video analysis. His current research interests include medical imaging, signal, image and video processing, motion and video analysis, pattern recognition, and biosignal analysis in ultrasound, magnetic resonance imaging, and computer applications in medicine. He is a Senior Member of the IEEE, serves as a reviewer in many IEEE Transactions and other journals and is a chair and co-chair at many IEEE conferences. He lives in Limassol, Cyprus, with his wife and children, a boy and a girl. Constantinos S. Pattichis was born in Cyprus on January 30, 1959 and received his diploma as technician engineer from the Higher Technical Institute in Cyprus in 1979, a B.Sc. in electrical engineering from the University of New Brunswick, Canada, in 1983, the M.Sc. in biomedical engineering from the University of Texas at Austin, USA, in 1984, an M.Sc. in neurology from the University of Newcastle Upon Tyne, UK, in 1991, and his Ph.D. in electronic engineering from the University of London, UK, in 1992. He is currently a Professor with the Department of Computer Science of the University of Cyprus. His research interests include ehealth and mhealth, medical imaging, biosignal analysis, life sciences informatics, and intelligent systems. He has been involved in numerous projects in these areas funded by EU, the National Research Foundation of Cyprus, the INTERREG and other bodies, like the FISTAR, GRANATUM, LINKED2SAFETY, MEDUCATOR, LONG LASTING MEMORIES, INTRAMEDNET, INTERMED, FUTURE HEALTH, AMBULANCE, EMERGENCY, ACSRS, TELEGYN, HEALTHNET, IASIS, IPPOKRATIS, and others with a total funding managed of more than 6 million Euros. He has published 90 refereed journaland 200 conference papers, and 27 chapters in books in these areas.