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Interhemispheric Difference Images from Postoperative Diffusion Tensor Imaging of Gliomas
Introduction Determining the full extent of gliomas during radiotherapy planning can be challenging with conventional T1 and T2 magnetic resonance imaging (MRI). The purpose of this study was to develop a method to automatically calculate differences in the fractional anisotropy (FA) and mean diffus...
Autores principales: | , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Cureus
2016
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5096944/ https://www.ncbi.nlm.nih.gov/pubmed/27843735 http://dx.doi.org/10.7759/cureus.817 |
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author | Kosztyla, Robert Reinsberg, Stefan A Moiseenko, Vitali Toyota, Brian Nichol, Alan |
author_facet | Kosztyla, Robert Reinsberg, Stefan A Moiseenko, Vitali Toyota, Brian Nichol, Alan |
author_sort | Kosztyla, Robert |
collection | PubMed |
description | Introduction Determining the full extent of gliomas during radiotherapy planning can be challenging with conventional T1 and T2 magnetic resonance imaging (MRI). The purpose of this study was to develop a method to automatically calculate differences in the fractional anisotropy (FA) and mean diffusivity (MD) values in target volumes obtained with diffusion tensor imaging (DTI) by comparing with values from anatomically homologous voxels on the contralateral side of the brain. Methods Seven patients with a histologically confirmed glioma underwent postoperative radiotherapy planning with 1.5 T MRI and computed tomography. DTI was acquired using echo planar imaging for 20 noncolinear directions with b = 1000 s/mm(2) and one additional image with b = 0, repeated four times for signal averaging. The distribution of FA and MD was calculated in the gross tumor volume (GTV), shells 0-5 mm, 5-10 mm, 10-15 mm, 15-20 mm, and 20-25 mm outside the GTV, and the GTV mirrored in the left-right direction (mirGTV). All images were aligned to a template image, and FA and MD interhemispheric difference images were calculated. The difference in mean FA and MD between the regions of interest was statistically tested using two-sided paired t-tests with α = 0.05. Results The mean FA in mirGTV was 0.20 ± 0.04, which was larger than the FA in the GTV (0.12 ± 0.03) and shells 0-5 mm (0.15 ± 0.03) and 5-10 mm (0.17 ± 0.03) outside the GTV. The mean MD (×10(-3) mm(2)/s) in mirGTV was 0.93 ± 0.09, which was smaller than the MD in the GTV (1.48 ± 0.19) and the peritumoral shells. The distribution of FA and MD interhemispheric differences followed the same trends as FA and MD values. Conclusions This study successfully implemented a method for calculation of FA and MD differences by comparison of voxel values with anatomically homologous voxels on the contralateral side of the brain. Further research is warranted to determine if radiotherapy planning using these images can be used to improve target delineation. |
format | Online Article Text |
id | pubmed-5096944 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2016 |
publisher | Cureus |
record_format | MEDLINE/PubMed |
spelling | pubmed-50969442016-11-14 Interhemispheric Difference Images from Postoperative Diffusion Tensor Imaging of Gliomas Kosztyla, Robert Reinsberg, Stefan A Moiseenko, Vitali Toyota, Brian Nichol, Alan Cureus Radiation Oncology Introduction Determining the full extent of gliomas during radiotherapy planning can be challenging with conventional T1 and T2 magnetic resonance imaging (MRI). The purpose of this study was to develop a method to automatically calculate differences in the fractional anisotropy (FA) and mean diffusivity (MD) values in target volumes obtained with diffusion tensor imaging (DTI) by comparing with values from anatomically homologous voxels on the contralateral side of the brain. Methods Seven patients with a histologically confirmed glioma underwent postoperative radiotherapy planning with 1.5 T MRI and computed tomography. DTI was acquired using echo planar imaging for 20 noncolinear directions with b = 1000 s/mm(2) and one additional image with b = 0, repeated four times for signal averaging. The distribution of FA and MD was calculated in the gross tumor volume (GTV), shells 0-5 mm, 5-10 mm, 10-15 mm, 15-20 mm, and 20-25 mm outside the GTV, and the GTV mirrored in the left-right direction (mirGTV). All images were aligned to a template image, and FA and MD interhemispheric difference images were calculated. The difference in mean FA and MD between the regions of interest was statistically tested using two-sided paired t-tests with α = 0.05. Results The mean FA in mirGTV was 0.20 ± 0.04, which was larger than the FA in the GTV (0.12 ± 0.03) and shells 0-5 mm (0.15 ± 0.03) and 5-10 mm (0.17 ± 0.03) outside the GTV. The mean MD (×10(-3) mm(2)/s) in mirGTV was 0.93 ± 0.09, which was smaller than the MD in the GTV (1.48 ± 0.19) and the peritumoral shells. The distribution of FA and MD interhemispheric differences followed the same trends as FA and MD values. Conclusions This study successfully implemented a method for calculation of FA and MD differences by comparison of voxel values with anatomically homologous voxels on the contralateral side of the brain. Further research is warranted to determine if radiotherapy planning using these images can be used to improve target delineation. Cureus 2016-10-05 /pmc/articles/PMC5096944/ /pubmed/27843735 http://dx.doi.org/10.7759/cureus.817 Text en Copyright © 2016, Kosztyla et al. http://creativecommons.org/licenses/by/3.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. |
spellingShingle | Radiation Oncology Kosztyla, Robert Reinsberg, Stefan A Moiseenko, Vitali Toyota, Brian Nichol, Alan Interhemispheric Difference Images from Postoperative Diffusion Tensor Imaging of Gliomas |
title | Interhemispheric Difference Images from Postoperative Diffusion Tensor Imaging of Gliomas |
title_full | Interhemispheric Difference Images from Postoperative Diffusion Tensor Imaging of Gliomas |
title_fullStr | Interhemispheric Difference Images from Postoperative Diffusion Tensor Imaging of Gliomas |
title_full_unstemmed | Interhemispheric Difference Images from Postoperative Diffusion Tensor Imaging of Gliomas |
title_short | Interhemispheric Difference Images from Postoperative Diffusion Tensor Imaging of Gliomas |
title_sort | interhemispheric difference images from postoperative diffusion tensor imaging of gliomas |
topic | Radiation Oncology |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5096944/ https://www.ncbi.nlm.nih.gov/pubmed/27843735 http://dx.doi.org/10.7759/cureus.817 |
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