The first three chapters provide background and basic knowledge, and the remaining chapters delve into image processing. The first chapter provides background information about the physics behind some clinically used imaging modalities and also includes a section on radiation safety. It touches on image acquisition using, amongst other modalities, x-ray, CT, MRI, ultrasound, nuclear medicine, and molecular imaging modalities. The majority of the photo illustrations in this chapter are of medical imaging equipment. Perhaps it would have been useful to also provide more illustrations with examples of the different types of medical images acquired with each equipment. In part, this is resolved in the new chapter 2, which provides examples of how medical images are used in modern clinical practice. The third chapter introduces the basic concepts of image representation. It introduces the definition of pixels and voxels, grayscale and color images, image formats such as DICOM, image quality, and signal-to-noise ratio.