Development of a system for measurement of bone mineral distribution patturn utilizing the dual energy subtraction technique

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(1) Construction of the system An image processing system was constructed using a laser film scanner and a work station, communicating with Ethernet network system. The system was able to input x-ray film images 1/6 cut size with 10 bit precision within 2min. including the image data transfer to the computer.A software system previously developed on a personal computer based system, was implemented to the UNIX system. The user I/O was full GUI type constructed using Open window system, based on the Open Look standard, and most manupilation could be performed by the mous.The system could output the quantitative bone minal content data of a pixel, the profile along a line which could be arbitrally defined, the projection in a given rectangle, and the integral in a given polygon. It took about 1 hour to process the image including the image scanning, which was longer than 15min. the purposed processing time of this project. The dominat factor of the processing time was sophisticated manup … More ilating procedure based on the user's judgment.(2) Version up based on the trial use (Pacage for the indivisual application field) In order to simplify the procedure, the automatic recognition argorithm was introduced to the identification of the positions of steel ball merkers and the reference wedge. The ramp shaped reference wedge was replaced by a step wedge, which required less precission of the position. The ROI for the integration was also specifyed semi-automatically by the binarization of the target bone image. The processing time of the new version reduced to 30min. We found that the processing time reduced subatantially if an appropreate set of the predicted positions were given. We decided to develop pacages specialized to the application field, in which the shape and position of the reference wedge, film size and x-ray factors were fixed. Firstly, the gerodontic filed was chosen as the target of the prototype of the pacage, because the variation of the objects were expected to be small. We started the survay of the variation of the gerodontic objects. The pacage was expected to realize the purposed processing time within 15min. Less