LAS develops systems for computer-based mathematical analysis, pattern recognition and image processing in support of diagnostic activities in the Nuclear Medicine Department of the Clinical Center and collaborating Institutes. Many applications are directed toward the correlation of function with structure, such as: estimation of ventricular function from radionuclide ventriculography or PET scan (functional data) compared to MRI or CT scans (anatomical data). Other applications are directed to special techniques such as the detection and imaging of tumors using radio-labelled monoclonal antibodies. LAS in collaboration with the Nuclear Medicine Department of the Clinical Center has, over the past five years, designed and specified a general- purpose image processing system, MIRAGe. Programming was performed by contractors supervised by LAS and the Nuclear Medicine Department. The completed basic system has been ported to several other NIH computer systems including VAX workstations and MacIntosh systems. Many academic and commercial institutions across North America and Europe have requested and received copies of the system.