This book offers a selective review of key imaging modalities focusing on modalities with established clinical utilization. It provides a detailed overview of x-ray imaging and computed tomography, fundamental concepts in signal acquisition and processes, followed by an overview of functional MRI (fMRI) and chemical shift imaging. It also covers topics in Magnetic Resonance Microcopy, the physics of instrumentation and signal collection, and their application in clinical practice. The selection of topics provides readers with an appreciation of the depth and breadth of the field and the challenges ahead of the technical and clinical community of researchers and practitioners.