Fast and accurate automated measurements in digitized stereophotogrammetric radiographs

摘要: Until recently, Roentgen Stereophotogrammetric Analysis (RSA) required the manual definition of all markers using a highresolution measurement table. To automate this tedious and time-consuming process to eliminate observer variabilities, an analytical software package has been developed validated for detection, identification, matching in RSA radiographs. The digital analysis procedure consisted following steps: (1) detection variant Hough circle-finder technique; (2) identification labeling detected markers; (3) reconstruction three-dimensional position bone prosthetic (4) computation micromotion. assess influence film digitization, measurements obtained from nine phantom radiographs two di⁄erent scanners were compared with results by processing. All automatically correctly labeled. best Vidar VXR-12 CCD scanner, which errors comparable associated approach. vivo reproducibility, 30 patient analyzed twice as well automated procedure. Approximately, 85% calibration matched. rigid-body show that accuracy is had mean values both techniques: 0.05 mm tibia 0.06 prosthesis. reproducibility showed be slightly better than maximum computed translation rotation tibial component 0.11 0.24i, 0.13 0.27i total processing time less 10 min per radiograph, including interactive corrections, approximately 1 h In conclusion, new widely applicable, computer-assisted technique become available detect, identify, match micromotion endoprostheses. This will used our clinic hip, knee, elbow studies. ( 1998 Elsevier Science Ltd. rights reserved.