HIGH-SENSITIVITY PHOSPHOR FOR X-RAY IMAGING

A NEW, INFRARED-STIMULABLE, ELECTRON-TRAPPING (ET(TM)) STORAGE PHOSPHOR HAS BEEN FOUND THAT IS EXTREMELY SENSITIVE TO X-RAY RADIATION. SUCH RADIATION POPULATES ELECTRON TRAPS IN THE MATERIAL, WHICH CAN RETAIN THE INFORMATION INDEFINITELY. THE NUMBER OF ELECTRONS IN THE TRAPS IS PROPORTIONAL TO THE AMOUNT OF RADIATION RECEIVED, SO A WIDER GRAY SCALE IS AVAILABLE FOR IMAGE FORMATION THAN WITH FILM/SCREEN RADIOGRAPHY. WHEN SCANNED BY A NEAR-INFRARED SOURCE, THE IMAGE APPEARS IN THE FORM OF A SPECTRALLY NARROW BAND OF EMISSION IN THE BLUE. PRELIMINARY EXPERIMENTS INDICATE THAT THE X-RAY SENSITIVITY MAY BE TWO ORDERS OF MAGNITUDE BETTER THAN CONVENTIONAL X-RAY FILM/SCREEN RADIOGRAPHY. THIS PROJECT IS DIRECTED TO THE FEASIBILITY EXAMINATION OF THESE NEW MATERIALS FOR THE PURPOSE OF ESTABLISHING A HIGHLY SENSITIVE PHOSPHOR FILM FOR CLINICAL X-RAY RADIOGRAPHY. THE PHASE I WORK WILL MAXIMIZE THE SENSITIVITY, CHARACTERIZE THE MATERIAL FOR LIKELY DQE'S AND MTF'S, AND EXAMINE THE READOUT TECHNIQUES REQUIRED FOR FORMING A PRACTICAL, RAPID-READOUT, REUSABLE, SOLID-STATE STORAGE SCREEN FOR CLINICAL RADIOGRAPHY.