A METAL-OXIDE CHARACTERISTIC-LINE X-RAY IMAGING SOURCE

THERE IS A NEED FOR A CORONARY-ARTERY DISEASE SCREENING METHOD NOT REQUIRING THE RISK OF AN ARTERIAL CATHETER. DIGITAL-SUBTRACTION RADIOGRAPHS USING IODINE-K-EDGE SUBTRACTION SUFFER FROM LOW X-RAY INTENSITIES AND REQUIRE LARGE IODINE CONCENTRATIONS PRECLUDING NON-INVASIVE TECHNIQUES. BRIGHTER X-RAY SOURCES ARE NEEDED. WE PROPOSE TO CONDUCT AN EVALUATION OF METAL OXIDES AS CHARACTERISTIC-LINE X-RAY EMITTERS. TWO TYPES OF DEVICES WILL BE CONSIDERED:(1) A HIGH-CURRENT PULSED X-RAY GUN WITH A METAL-OXIDE-COATED THIN-TARGET WINDOW, (2) A COMMERCIALLY AVAILABLE X-RAY TUBE WITH A MODIFIED METAL-OXIDE-COATED ROTATING ANODE. THESE SOURCES ARE EXPECTED TO PRODUCE A USEFUL FLUX FOR K-EDGE DICHROMOGRAPHY OF APPROXIMATELY 50 TIMES GREATER THAN THAT OF FILTERED BREMSSTRAH-LUNG. WE HAVE ALSO DEVELOPED A COMPUTER SIMULATION OF IODINE-K-EDGE DICHROMOGRAPHY WHICH DETERMINES THE X-RAY FLUX NEEDED FROM IMAGING WITH A PARTICULAR X-RAY-DETECTOR SYSTEM. THIS SIMULATION TOGETHER WITH AN ESTIMATE OF THE CHARACTERISTIC-LINE X-RAY PRODUCTION OF OUR SOURCES, INDICATE THAT IODINE-K-EDGE DICHROMOGRAPHY IS POSSIBLE. WE WILL HAVE AT OUR DISPOSAL CRITICAL RESEARCH FACILITIES OF VARIAN ASSOCIATES, THE STANFORD LINEAR ACCELERATOR CENTER, AND ADELPHI TECHNOLOGY INC. THIS INCLUDES X-RAY DETECTION EQUIPMENT, X-RAY SOURCES, AND VAPOR-DEPOSITION FACILITIES. WE HAVE DEVELOPED A DIGITAL X-RAY-IMAGING SYSTEM WHICH IS ALSO AVAILABLE FOR THIS WORK. ADELPHI TECHNOLOGY INC. HAS EXTENSIVE EXPERIENCE DEVELOPING ADVANCED X-RAY SOURCES FOR MEDICAL, SCIENTIFIC, AND INDUSTRIAL APPLICATIONS. A MEDICALDIAGNOSTIC IMAGING SYSTEM BASED UPON THE CHARACTERISTIC-LINESOURCE BEING DEVELOPED HERE PROMISES A MODERATE-COST NON-INVASIVE METHOD FOR SCREENING ATHEROSCLEROSIS.