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Validation of a deformable MRI to CT registration algorithm employing same day planning MRI for surrogate analysis

PURPOSE: Validating deformable multimodality image registrations is challenging due to intrinsic differences in signal characteristics and their spatial intensity distributions. Evaluating multimodality registrations using these spatial intensity distributions is also complicated by the fact that th...

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Autores principales: Padgett, Kyle R., Stoyanova, Radka, Pirozzi, Sara, Johnson, Perry, Piper, Jon, Dogan, Nesrin, Pollack, Alan
Formato: Online Artículo Texto
Lenguaje:English
Publicado: John Wiley and Sons Inc. 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5849829/
https://www.ncbi.nlm.nih.gov/pubmed/29476603
http://dx.doi.org/10.1002/acm2.12296
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author Padgett, Kyle R.
Stoyanova, Radka
Pirozzi, Sara
Johnson, Perry
Piper, Jon
Dogan, Nesrin
Pollack, Alan
author_facet Padgett, Kyle R.
Stoyanova, Radka
Pirozzi, Sara
Johnson, Perry
Piper, Jon
Dogan, Nesrin
Pollack, Alan
author_sort Padgett, Kyle R.
collection PubMed
description PURPOSE: Validating deformable multimodality image registrations is challenging due to intrinsic differences in signal characteristics and their spatial intensity distributions. Evaluating multimodality registrations using these spatial intensity distributions is also complicated by the fact that these metrics are often employed in the registration optimization process. This work evaluates rigid and deformable image registrations of the prostate in between diagnostic‐MRI and radiation treatment planning‐CT by utilizing a planning‐MRI after fiducial marker placement as a surrogate. The surrogate allows for the direct quantitative analysis that can be difficult in the multimodality domain. METHODS: For thirteen prostate patients, T2 images were acquired at two different time points, the first several weeks prior to planning (diagnostic‐MRI) and the second on the same day as the planning‐CT (planning‐MRI). The diagnostic‐MRI was deformed to the planning‐CT utilizing a commercially available algorithm which synthesizes a deformable image registration (DIR) algorithm from local rigid registrations. The planning‐MRI provided an independent surrogate for the planning‐CT for assessing registration accuracy using image similarity metrics, including Pearson correlation and normalized mutual information (NMI). A local analysis was performed by looking only within the prostate, proximal seminal vesicles, penile bulb, and combined areas. RESULTS: The planning‐MRI provided an excellent surrogate for the planning‐CT with residual error in fiducial alignment between the two datasets being submillimeter, 0.78 mm. DIR was superior to the rigid registration in 11 of 13 cases demonstrating a 27.37% improvement in NMI (P < 0.009) within a regional area surrounding the prostate and associated critical organs. Pearson correlations showed similar results, demonstrating a 13.02% improvement (P < 0.013). CONCLUSION: By utilizing the planning‐MRI as a surrogate for the planning‐CT, an independent evaluation of registration accuracy is possible. This population provides an ideal testing ground for MRI to CT DIR by obviating the need for multimodality comparisons which are inherently more challenging.
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spelling pubmed-58498292018-04-02 Validation of a deformable MRI to CT registration algorithm employing same day planning MRI for surrogate analysis Padgett, Kyle R. Stoyanova, Radka Pirozzi, Sara Johnson, Perry Piper, Jon Dogan, Nesrin Pollack, Alan J Appl Clin Med Phys Radiation Oncology Physics PURPOSE: Validating deformable multimodality image registrations is challenging due to intrinsic differences in signal characteristics and their spatial intensity distributions. Evaluating multimodality registrations using these spatial intensity distributions is also complicated by the fact that these metrics are often employed in the registration optimization process. This work evaluates rigid and deformable image registrations of the prostate in between diagnostic‐MRI and radiation treatment planning‐CT by utilizing a planning‐MRI after fiducial marker placement as a surrogate. The surrogate allows for the direct quantitative analysis that can be difficult in the multimodality domain. METHODS: For thirteen prostate patients, T2 images were acquired at two different time points, the first several weeks prior to planning (diagnostic‐MRI) and the second on the same day as the planning‐CT (planning‐MRI). The diagnostic‐MRI was deformed to the planning‐CT utilizing a commercially available algorithm which synthesizes a deformable image registration (DIR) algorithm from local rigid registrations. The planning‐MRI provided an independent surrogate for the planning‐CT for assessing registration accuracy using image similarity metrics, including Pearson correlation and normalized mutual information (NMI). A local analysis was performed by looking only within the prostate, proximal seminal vesicles, penile bulb, and combined areas. RESULTS: The planning‐MRI provided an excellent surrogate for the planning‐CT with residual error in fiducial alignment between the two datasets being submillimeter, 0.78 mm. DIR was superior to the rigid registration in 11 of 13 cases demonstrating a 27.37% improvement in NMI (P < 0.009) within a regional area surrounding the prostate and associated critical organs. Pearson correlations showed similar results, demonstrating a 13.02% improvement (P < 0.013). CONCLUSION: By utilizing the planning‐MRI as a surrogate for the planning‐CT, an independent evaluation of registration accuracy is possible. This population provides an ideal testing ground for MRI to CT DIR by obviating the need for multimodality comparisons which are inherently more challenging. John Wiley and Sons Inc. 2018-02-23 /pmc/articles/PMC5849829/ /pubmed/29476603 http://dx.doi.org/10.1002/acm2.12296 Text en © 2018 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine. This is an open access article under the terms of the http://creativecommons.org/licenses/by/4.0/ License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
spellingShingle Radiation Oncology Physics
Padgett, Kyle R.
Stoyanova, Radka
Pirozzi, Sara
Johnson, Perry
Piper, Jon
Dogan, Nesrin
Pollack, Alan
Validation of a deformable MRI to CT registration algorithm employing same day planning MRI for surrogate analysis
title Validation of a deformable MRI to CT registration algorithm employing same day planning MRI for surrogate analysis
title_full Validation of a deformable MRI to CT registration algorithm employing same day planning MRI for surrogate analysis
title_fullStr Validation of a deformable MRI to CT registration algorithm employing same day planning MRI for surrogate analysis
title_full_unstemmed Validation of a deformable MRI to CT registration algorithm employing same day planning MRI for surrogate analysis
title_short Validation of a deformable MRI to CT registration algorithm employing same day planning MRI for surrogate analysis
title_sort validation of a deformable mri to ct registration algorithm employing same day planning mri for surrogate analysis
topic Radiation Oncology Physics
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5849829/
https://www.ncbi.nlm.nih.gov/pubmed/29476603
http://dx.doi.org/10.1002/acm2.12296
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