Robust automatic C-arm calibration for fluoroscopy-based navigation: 
a practical approach

H. Livyatan, Z. Yaniv, L. Joskowicz

School of Computer Science and Engineering 
The Hebrew University of Jerusalem, Jerusalem 91904, Israel.

Abstract: 

This paper presents a new on-line automatic X-ray fluoroscopic C-arm
calibration method for intraoperative use.  C-arm calibration is an
essential prerequisite for accurate X-ray fluoroscopy-based navigation and
image-based registration.  Our method utilizes a custom-designed
calibration ring with a two-plane pattern of fiducials that attaches to the
C-arm image intensifier, and an on-line calibration algorithm.  The
algorithm is robust, fully automatic, and works with images containing
anatomy and surgical instruments which cause fiducial occlusions.  It
consists of three steps: fiducial localization, distortion correction, and
camera calibration.  Our experimental results show submillimetric accuracy
for calibration and tip localization with occluded fiducials.


Proc. 5th Int. Conf. on Medical Image Computing and Computer-Aided
Intervention, MICCAI 2002, October 2002, Tokyo, Japan. Lecture Notes in
Computer Science 2488. Dohi, T. and Kikinis, R.  editors, Berlin: Springer,
2002. Vol. 2. pp. 60-68.