This book provides a comprehensive overview of the technologies and techniques used to obtain and reconstruct tomographic images, which are essential for many medical and scientific applications. It presents a summary of the acquisition systems that are at the heart of tomography, enabling the collection of data necessary for image reconstruction. These systems include various modalities, each with its own advantages and limitations. This book also proposes reconstruction methods that transform the raw data collected by acquisition systems into interpretable images. Technological and methodological advances continue to improve image quality, reducing noise and artefacts while increasing diagnostic accuracy. Challenges related to computational complexity and data management are gradually being overcome through continuous innovation. The future of tomography lies in the integration of new technologies and the optimisation of existing methods to provide high-quality images.