Imaging techniques: state and future.

Technical progress has produced a variety of novel imaging techniques (digital projection radiography, X-ray-transmission computed tomography, sonography, single photon emission computed tomography, positron emission tomography, magnetic resonance imaging), and has enormously extended the diagnostic possibilities in industrialized countries. Further technological developments will be considered under three aspects: --Improvement of current imaging procedures and opening-up of new applications --introduction of new imaging techniques --progressive use of computer technology in imaging diagnostics [digital image generation, image processing, image archiving and communication systems (PACS)] Finally, several consequences emerging from these aspects will be discussed.