Physics and applications of medical imaging

Medical imaging is the principal method for noninvasively obtaining anatomi c and physiologic information about the human body. Imaging has experienced a quantum leap in technology and clinical applications over the past 25 ye ars. This leap includes x-ray computed tomography (CT); emission computed t omography (SPECT and PET); magnetic-resonance imaging (MRI) and spectroscop y (MRS), including functional MRI (fMRI), and the networking of images in d igital networks (PACS and IMACS). Even traditional projection x-ray imaging is undergoing a major change with the advent of digital x-ray image recept ors. Images are important not only to the detection and diagnosis of diseas e and injury, but also to the design, delivery, and monitoring of treatment . The evolution of medical imaging is the product of physicists working in collaboration with engineers and physicians. Further advances are limited o nly by the creativity and imagination of these individuals. [S0034-6861(99) 03702-2].