AN X-RAY-SENSITIVE REAL-TIME SPATIAL LIGHT MODULATOR IS PROPOSED AS A REPLACEMENT FOR PHOTOGRAPHIC FILM FOR MEDICAL IMAGING APPLICATIONS (A) IN WHICH TIME IS OF THE ESSENCE, (B) THAT EMPLOY LOW X-RAY ENERGIES (E.

AN X-RAY-SENSITIVE REAL-TIME SPATIAL LIGHT MODULATOR IS PROPOSED AS A REPLACEMENT FOR PHOTOGRAPHIC FILM FOR MEDICAL IMAGING APPLICATIONS (A) IN WHICH TIME IS OF THE ESSENCE, (B) THAT EMPLOY LOW X-RAY ENERGIES (E.G. ONCOLOGY) AND (C) FOR THE DIAGNOSIS OF TISSUE MOVEMENT (E.G. ACTION OF THE JOINTS) IN REAL TIME. THE DEVICE BEING PROPOSED IS A MODIFIED VERSION OF THE MICROCHANNEL SPATIAL LIGHT MODULATOR (MSLM). THE MSLM EMPLOYS A MICROCHANNEL PLATE AND A HIGH-RESISTIVITY ELECTRO-OPTIC CRYSTAL. THE MCP CONVERTS X-RAY IMAGES INTO ELECTRON IMAGES AND DEPOSITS THE ELECTRON IMAGE ON THE CYRSTAL. THE RESULTING ELECTRIC FIELD IN THE CRYSTAL MODULATES THE REFRACTIVE INDEX OF THE CRYSTAL AND THEREBY ALTERS THE POLARIZATION OF THE READOUT OPTICAL BEAM. AN OPTICAL INTENSITY IMAGE IS RECOVERED BY THE USE OF A POLARIZING ANALYSER. IN THE PHASE I RESEARCH PROGRAM WE EXPECT TO DEMONSTRATE THE FEASIBILITY OF X-RAY IMAGE CONVERSION, AND TO CHARACTERIZE THE SPATIAL RESOLUTION, FRAMING SPEED, STORAGE CHARACTERISTICS, AND EXPOSURE SENSITIVITY OF THE DEVICE. THE PHASE II RESEARCH PLAN WILL BE CONCERNED WITH THE PROBLEMS OF SCALING THE ACTIVE AREA OF THE DEVICE UP TO ABOUT 6 INCHES IN DIAMETER. IT IS EXPECTED THAT THE DEVICE WILL FIND WIDESPREAD USE IN HOSPITALS, ON THE BATTLE FIELD, AND IN VETERINARY MEDICINE.