Model-based geometric calibration for medical x-ray systems

Med Phys. 2015 Nov;42(11):6170-81. doi: 10.1118/1.4931964.

Abstract

Purpose: Currently applied calibration approaches lead to satisfying 3D roadmapping overlay and 3D reconstruction accuracies; however, the required calibration times are extensive. The aim of this paper is the introduction of a novel model-based approach for geometric system calibrations, leading to a significant reduction of calibration times.

Methods: By using physical insight into the system, a physical model is derived which can be exploited to predict geometric calibrations parameters. Model-parameters are estimated using a limited set of phantom-based measurement data. Effectively, the calibration procedure is recast to a parameter identification experiment.

Results: The potential of the proposed approach is illustrated by virtue of a benchmark object, successful reconstruction of a clinical phantom, and comparison to phantom-based accuracies.

Conclusions: Accurate models are required to achieve the desired accuracies. Based on the results in this work, the approach seems to be feasible for practical applications; however, to achieve all the desired specifications, future research should focus on enhanced modeling techniques.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Algorithms*
  • Calibration / standards
  • Humans
  • Imaging, Three-Dimensional / methods*
  • Imaging, Three-Dimensional / standards
  • Internationality
  • Radiographic Image Enhancement / methods*
  • Radiographic Image Enhancement / standards
  • Radiographic Image Interpretation, Computer-Assisted / methods*
  • Radiographic Image Interpretation, Computer-Assisted / standards
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Tomography, X-Ray Computed / methods*
  • Tomography, X-Ray Computed / standards