Automatic measurements of image geometry for online calibration of C-arm fluoroscopy.
Calibrated C-arm fluoroscopy is used for a variety of surgical procedures where surgical tools and anatomical structures need to be located in space. Calibration can be performed online by combining measurements of the geometry of the image (center and radius) with measurements of a grid of fiducial markers. This article focuses on the first aspect--image geometry--and describes a method to perform the geometry measurements automatically. The accuracy, robustness, and speed of the method are validated on 100 images obtained from several hospitals with different C-arm scanners. All 100 images were successfully measured with an average error of 0.8 mm for the center and 0.8 mm for the radius. The execution time is less than one second per image.
Department of Electrical and Computer Engineering, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada. neculai.archip@ece.ubc.ca
Neculai
N
Archip
Robert
R
Rohling
D000465:Algorithms; D002138:Calibration / Q000592:standards; D005060:Europe; D005471:Fluoroscopy / Q000295:instrumentation* / Q000379:methods*; D006801:Humans; D009656:North America; D009862:Online Systems; D011856:Radiographic Image Enhancement / Q000379:methods*; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D011881:Radiotherapy, Computer-Assisted / Q000379:methods; D025321:Surgery, Computer-Assisted / Q000379:methods*