A practical technique has been developed for obtaining accurate three-dimensional positions of multiple identical moving spherical radiopaque markers using conventional biplane cineradiographic systems. Using a cineradiographic system operating at 90 frames/s, we are obtaining an rms accuracy of 0.1 mm in measuring the position of multiple 1-mm-diameter markers in a variety of test objects including canine ventricles in vivo. The high accuracy permits automatic image pairing between biplane views. The accuracy is achieved by making some additional exposures with special fixtures containing similar makers placed in known positions to provide the information to compute system distortions and X-ray source and film plane locations. The positions of the images of these markers and the markers in the test object are digitized for computer processing to determine the three-dimensional trajectory of each marker during the test sequence. No modification of the X-ray system is required, and no special setup or alignment procedures are required. This report describes the principles of the method and the logic of the computer programs for processing the data.
ASJC Scopus subject areas
- Medicine (miscellaneous)