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Multimodality calibration for simultaneous fluoroscopic and nuclear imaging
BACKGROUND: Simultaneous real-time fluoroscopic and nuclear imaging could benefit image-guided (oncological) procedures. To this end, a hybrid modality is currently being developed by our group, by combining a c-arm with a gamma camera and a four-pinhole collimator. Accurate determination of the sys...
Autores principales: | , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Springer International Publishing
2016
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5005238/ https://www.ncbi.nlm.nih.gov/pubmed/27576333 http://dx.doi.org/10.1186/s40658-016-0156-1 |
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author | Beijst, Casper Elschot, Mattijs van der Velden, Sandra de Jong, Hugo W. A. M. |
author_facet | Beijst, Casper Elschot, Mattijs van der Velden, Sandra de Jong, Hugo W. A. M. |
author_sort | Beijst, Casper |
collection | PubMed |
description | BACKGROUND: Simultaneous real-time fluoroscopic and nuclear imaging could benefit image-guided (oncological) procedures. To this end, a hybrid modality is currently being developed by our group, by combining a c-arm with a gamma camera and a four-pinhole collimator. Accurate determination of the system parameters that describe the position of the x-ray tube, x-ray detector, gamma camera, and collimators is crucial to optimize image quality. The purpose of this study was to develop a calibration method that estimates the system parameters used for reconstruction. A multimodality phantom consisting of five point sources was created. First, nuclear and fluoroscopic images of the phantom were acquired at several distances from the image intensifier. The system parameters were acquired using physical measurement, and multimodality images of the phantom were reconstructed. The resolution and co-registration error of the point sources were determined as a measure of image quality. Next, the system parameters were estimated using a calibration method, which adjusted the parameters in the reconstruction algorithm, until the resolution and co-registration were optimized. For evaluation, multimodality images of a second set of phantom acquisitions were reconstructed using calibrated parameter sets. Subsequently, the resolution and co-registration error of the point sources were determined as a measure of image quality. This procedure was performed five times for different noise simulations. In addition, simultaneously acquired fluoroscopic and nuclear images of two moving syringes were obtained with parameter sets from before and after calibration. RESULTS: The mean FWHM was significantly lower after calibration than before calibration for 21 out of 25 point sources. The mean co-registration error was significantly lower after calibration than before calibration for all point sources. The simultaneously acquired fluoroscopic and nuclear images showed improved co-registration after calibration as compared with before calibration. CONCLUSIONS: A calibration method was presented that improves the resolution and co-registration of simultaneously acquired hybrid fluoroscopic and nuclear images by estimating the geometric parameter set as compared with a parameter set acquired by direct physical measurement. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s40658-016-0156-1) contains supplementary material, which is available to authorized users. |
format | Online Article Text |
id | pubmed-5005238 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2016 |
publisher | Springer International Publishing |
record_format | MEDLINE/PubMed |
spelling | pubmed-50052382016-09-22 Multimodality calibration for simultaneous fluoroscopic and nuclear imaging Beijst, Casper Elschot, Mattijs van der Velden, Sandra de Jong, Hugo W. A. M. EJNMMI Phys Original Research BACKGROUND: Simultaneous real-time fluoroscopic and nuclear imaging could benefit image-guided (oncological) procedures. To this end, a hybrid modality is currently being developed by our group, by combining a c-arm with a gamma camera and a four-pinhole collimator. Accurate determination of the system parameters that describe the position of the x-ray tube, x-ray detector, gamma camera, and collimators is crucial to optimize image quality. The purpose of this study was to develop a calibration method that estimates the system parameters used for reconstruction. A multimodality phantom consisting of five point sources was created. First, nuclear and fluoroscopic images of the phantom were acquired at several distances from the image intensifier. The system parameters were acquired using physical measurement, and multimodality images of the phantom were reconstructed. The resolution and co-registration error of the point sources were determined as a measure of image quality. Next, the system parameters were estimated using a calibration method, which adjusted the parameters in the reconstruction algorithm, until the resolution and co-registration were optimized. For evaluation, multimodality images of a second set of phantom acquisitions were reconstructed using calibrated parameter sets. Subsequently, the resolution and co-registration error of the point sources were determined as a measure of image quality. This procedure was performed five times for different noise simulations. In addition, simultaneously acquired fluoroscopic and nuclear images of two moving syringes were obtained with parameter sets from before and after calibration. RESULTS: The mean FWHM was significantly lower after calibration than before calibration for 21 out of 25 point sources. The mean co-registration error was significantly lower after calibration than before calibration for all point sources. The simultaneously acquired fluoroscopic and nuclear images showed improved co-registration after calibration as compared with before calibration. CONCLUSIONS: A calibration method was presented that improves the resolution and co-registration of simultaneously acquired hybrid fluoroscopic and nuclear images by estimating the geometric parameter set as compared with a parameter set acquired by direct physical measurement. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s40658-016-0156-1) contains supplementary material, which is available to authorized users. Springer International Publishing 2016-08-30 /pmc/articles/PMC5005238/ /pubmed/27576333 http://dx.doi.org/10.1186/s40658-016-0156-1 Text en © The Author(s). 2016 Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. |
spellingShingle | Original Research Beijst, Casper Elschot, Mattijs van der Velden, Sandra de Jong, Hugo W. A. M. Multimodality calibration for simultaneous fluoroscopic and nuclear imaging |
title | Multimodality calibration for simultaneous fluoroscopic and nuclear imaging |
title_full | Multimodality calibration for simultaneous fluoroscopic and nuclear imaging |
title_fullStr | Multimodality calibration for simultaneous fluoroscopic and nuclear imaging |
title_full_unstemmed | Multimodality calibration for simultaneous fluoroscopic and nuclear imaging |
title_short | Multimodality calibration for simultaneous fluoroscopic and nuclear imaging |
title_sort | multimodality calibration for simultaneous fluoroscopic and nuclear imaging |
topic | Original Research |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5005238/ https://www.ncbi.nlm.nih.gov/pubmed/27576333 http://dx.doi.org/10.1186/s40658-016-0156-1 |
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