High-contrast object localization and removal in cone-beam CT

摘要: ABSTRACT In image-guided procedures high-contrast objects often app ear in the imaging field-of-view for purpose of guidingtreatment (e.g., markers intended to localize target) or delivering treatment surgical tools, case brachytherapy, radioactive seeds). cone-beam CT reconstructions, these cause severe streakartifacts, number inaccuracy and loss soft-tissue visibility. We have developed an iterative approach by which are localized 2-D projection set re-projecting conspicuities from first-pass 3-Dreconstruction. The operator, finds unique mapping world coordinate system thedetector each view angle, is computed a geometric calibration system. projection, two-dimensional 2 nd order Taylor series used interpolate over objects. Theinterpolated surface further modified using local noise estimate completely mask algorithm has been applied remove artifacts resulting small num ber gold fiducial patients being imaged dailywith guidance prostate radiotherapy. also post-operative imagesof brachytherapy patient seeds can exceed ~100. case, method provides excellent attenuation image artifact restoration Using voxel based metric it was shown that