Medical Imaging

　　The field of medical imaging advances so rapidly that knowledge needs to be frequently updated in order to stay abreast of developments. The book is designed for medical professionals, who wish to update their skills and understanding with the latest techniques in image analysis, for professionals in medical imaging technology, and for computer scientists and electrical engineers, who want to specialize in the medical applications. In this book, we have made an effort to cover the fundamentals of medical imaging and medical image analysis along with brief descriptions of recent developments. The book emphasizes not only on the background theory but also on the practical aspects of medical image analysis, which include the effective use of available image processing tools. A number of medical image analysis systems and databases, both commercial and free, are described in this book. We hope that this book gives readers a sense of the breadth of medical imaging, medical image analysis and associated challenges while providing them with the basic tools to take the challenge.

　　Chapter 1 presents an overview of medical imaging modalities and their role in medicine. A light introduction about various medical imaging modalities with four kinds of classification approaches is given.

　　Chapter 2 describes the basic principles of image formation and reviews the essential mathematical foundation and digital image theory.

　　Chapter 3 presents basic principles of DICOM stands (Digital Imaging and COmmunications in Medicine) and PACS (Picture Archiving and Communication Systems) in medical imaging.

　　Chapter 4 describes the principles, instrumentation, and data acquisition methods of Magnetic resonance imaging (MRI). A four dimensional cardiac MR image analysis application is discussed.

　　Chapter 5 provides a complete spectrum of biological microscopic image analysis. Recent development on computer-aided microscopic image analysis tools are discussed.

　　Chapter 6 discusses the principles, instrumentation, and data acquisition methods of X-ray imaging modalities, including X-ray radiograph imaging, X-ray mammography, and X-ray CT. Public CT databases and computer-aided diagnosis applications are also described.

　　Chapter 7 provides ultrasound imaging principles and discusses methods for data acquisition and instrumentation control systems.

　　Chapter 8 presents a detailed introduction to a free and open source image processing software (ImageJ / Fiji), which are popularly adopted in the medical image analysis community. Related or extended medical image analysis tools are also described.

作者簡介

Professor Ching-Wei Wang

　　Professor Ching-Wei Wang obtained her MSc with Distinction in Computer Science from University of Glasgow, UK, and a PhD in Computer Science from University of Lincoln, UK. Ching-Wei is the director of Biomedical Image and Computer Vision Lab in the Graduate Institute of Biomedical Engineering at the National Taiwan University of Science and Technology, and she has years of working experiences in computer vision and machine learning. Her current interests include automatic detection, segmentation, recognition, reconstruction and image registration for 2D/3D microscopic image, 3D/4D Cardiac MRI Image, Ultrasound Image, 3D confocal image, 3D CT scan, X ray image, live cell image and infrared image/video data. Ching-Wei has won a number of awards and prize. Recent ones 2012-2013 are listed below.

　　• 1st Prize, the 4th Annual Creative Entrepreneurship Competition ─ New Business Development Group, National Taiwan University of Science and Technology, 2013.5

　　• Young Scholar Award, National Taiwan University of Science and Technology, 2013.1-2015.12

　　• Excellence in Research Award, National Taiwan University of Science and Technology, 2013.2-2016.1

　　• Second place, Right Ventricle Segmentation Challenge in 4D Cardiac MRI, 2012 (organized by Université de Rouen, sponsored by Toshiba, PIE Medical Imaging and Medis)

　　• First Prize, Fetal Femur Ultrasound Image Segmentation Challenge (organized by Oxford University), 2012

　　• Distinguished Young Scholar 3-Years Research Fund, by National Science Council of Taiwan, 2012/7-2015/6

　　Ching-Wei’s professional experience in industry is in building real time intelligent automatic computer vision systems. She has a number of patents and has successfully sold some of her technologies to the industry.

Professor Keng-Liang Ou

　　Professor Keng-Liang Ou obtained his Ph.D. degree from Graduate Institute of Mechanical Engineering, National Chiao Tung University, Taiwan. He joined Taipei Medical University to pursue the cutting-edge research of biomaterials and currently holds the position of Dean of College of Oral Medicine. He is also the Director of Research Center for Biomedical Implants and Microsurgery Devices and the Director of Research Center for Biomedical Devices and Prototyping Production. Besides institutional appointment, Prof. Ou serves as the President of Institute of Plasma Engineering in Taiwan, the Director of the Taiwan Society for Metal Heat Treatment, the President of Taiwan Oral Biomedical Engineering Association and the Director of Yongee Anti-cancer Foundation. Professor Ou devotes himself to the novel research in the fields of biomaterials, bioengineering, biosensing, bioimaging, and translational medicine. In addition, he establishes extensive collaborations with industry and has played a leading role in developing medical devices for health professionals worldwide. He is the leader and organizer for the biomedical product design, production, manufacturing, testing, legalization and market planning, with supports from teams of scientists and researchers with expertise in different fields. With the outstanding accomplishments in research and invention, Professor Ou received the Award of the Ten Outstanding Young Persons of Taiwan in the year of 2011 and the TMU Distinguished University Professor Award in 2014.

Medical imaging technologies enable views of the internal structure and function of the human body. Information obtained from the various modalities can be used to diagnose abnormalities, guide therapeutic procedures, and monitor disease treatment. In this chapter, a light introduction about various medical imaging modalities with four kinds of classification approaches is given.
 
1.1 Classifications of Electromagnetic Radiation Spectrum
Electromagnetic radiation consists of alternating electric and magnetic fields. In an electromagnetic wave, these fields are directed perpendicular to each other and to the direction of propagation. They are classified by the frequency ν and wavelength λ. In free space, all electromagnetic waves travel with the speed of light, c ≈ 3×108 ms-1. The propagation speed establishes the relation between wavelength λ and frequency ν of an electromagnetic wave as
λν = c.

The frequency is measured in cycles per second (Hz or s-1) and the wavelength in meters (m).
 
Figure 1-1 illustrates that electromagnetic waves span an enormous frequency and wavelength range of 24 decades, and only a tiny fraction from about 400-700 nm, about one octave, falls in the visible region to the human eye. In matter, the electric and magnetic fields of the electromagnetic wave interact with the electric charges, electric currents, electric fields, and magnetic fields in the medium. Nonetheless, the basic nature of electromagnetic waves remains the same, only the propagation of the wave is slowed down and the wave is attenuated. Electromagnetic waves are generally a linear phenomenon. This means that we can decompose any complex wave pattern into basic ones such as plane harmonic waves. Or, conversely, we can superimpose any two or more electro- magnetic waves and be sure that they are still electromagnetic waves.