Medical Tomographic Imaging Techniques: A Brief Conceptual Review

This paper provides a comprehensive overview of tomography and the various tomographic imaging modalities available today. Its primary aim is to offer readers a foundational understanding of these imaging techniques, focusing on how imaging is conducted, the underlying principles of operation, and their practical applications. Instead of going in-depth into the mathematical theories behind each modality, the paper is intended to present the information in a clear and accessible manner for the benefit of a broad audience. The imaging modalities discussed are categorized based on the physics and math behind their image formation. The paper begins by introducing the general concept of tomography and then explores specific modalities in detail, including Computed Tomography (CT), Ultrasound Imaging, Magnetic Resonance Imaging (MRI), Electrical Impedance Tomography, Photoacoustic Tomography (PAT), and Positron Emission Tomography (PET). In addition, the paper examines two emerging imaging modalities, Diffuse Optical Spectroscopic Tomography (DOST) and functional Near-infrared Spectroscopy (fNIRS), offering a review of their fundamentals and potential applications. This structured approach ensures readers gain a solid conceptual understanding of a wide range of imaging technologies.