Share Email Print

Proceedings Paper

Towards real-time 2D/3D registration for organ motion monitoring in image-guided radiation therapy
Author(s): C. Gendrin; J. Spoerk; C. Bloch; S. A. Pawiro; C. Weber; M. Figl; P. Markelj; F. Pernus; D. Georg; H. Bergmann; W. Birkfellner
Format Member Price Non-Member Price
PDF $17.00 $21.00

Paper Abstract

Nowadays, radiation therapy systems incorporate kV imaging units which allow for the real-time acquisition of intra-fractional X-ray images of the patient with high details and contrast. An application of this technology is tumor motion monitoring during irradiation. For tumor tracking, implanted markers or position sensors are used which requires an intervention. 2D/3D intensity based registration is an alternative, non-invasive method but the procedure must be accelerate to the update rate of the device, which lies in the range of 5 Hz. In this paper we investigate fast CT to a single kV X-ray 2D/3D image registration using a new porcine reference phantom with seven implanted fiducial markers. Several parameters influencing the speed and accuracy of the registrations are investigated. First, four intensity based merit functions, namely Cross-Correlation, Rank Correlation, Mutual Information and Correlation Ratio, are compared. Secondly, wobbled splatting and ray casting rendering techniques are implemented on the GPU and the influence of each algorithm on the performance of 2D/3D registration is evaluated. Rendering times for a single DRR of 20 ms were achieved. Different thresholds of the CT volume were also examined for rendering to find the setting that achieves the best possible correspondence with the X-ray images. Fast registrations below 4 s became possible with an inplane accuracy down to 0.8 mm.

Paper Details

Date Published: 23 February 2010
PDF: 9 pages
Proc. SPIE 7625, Medical Imaging 2010: Visualization, Image-Guided Procedures, and Modeling, 762512 (23 February 2010); doi: 10.1117/12.844201
Show Author Affiliations
C. Gendrin, Medical Univ. Vienna (Austria)
J. Spoerk, Medical Univ. Vienna (Austria)
C. Bloch, Medical Univ. Vienna (Austria)
S. A. Pawiro, Medical Univ. Vienna (Austria)
C. Weber, Medical Univ. Vienna (Austria)
M. Figl, Medical Univ. Vienna (Austria)
P. Markelj, Univ. of Ljubljana (Slovenia)
F. Pernus, Univ. of Ljubljana (Slovenia)
D. Georg, Medical Univ. Vienna (Austria)
H. Bergmann, Medical Univ. Vienna (Austria)
W. Birkfellner, Medical Univ. Vienna (Austria)

Published in SPIE Proceedings Vol. 7625:
Medical Imaging 2010: Visualization, Image-Guided Procedures, and Modeling
Kenneth H. Wong; Michael I. Miga, Editor(s)

© SPIE. Terms of Use
Back to Top
Sign in to read the full article
Create a free SPIE account to get access to
premium articles and original research
Forgot your username?