Partial Volume Reduction by Interpolation with Reverse Diffusion

Many medical images suffer from the partial volume effect where a boundary between two structures of interest falls in the midst of a voxel giving a signal value that is a mixture of the two. We propose a method to restore the ideal boundary by splitting a voxel into subvoxels and reapportioning the...

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Main Authors: Olivier Salvado, Claudia M. Hillenbrand, David L. Wilson
Format: Article
Language:English
Published: Wiley 2006-01-01
Series:International Journal of Biomedical Imaging
Online Access:http://dx.doi.org/10.1155/IJBI/2006/92092
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author Olivier Salvado
Claudia M. Hillenbrand
David L. Wilson
author_facet Olivier Salvado
Claudia M. Hillenbrand
David L. Wilson
author_sort Olivier Salvado
collection DOAJ
description Many medical images suffer from the partial volume effect where a boundary between two structures of interest falls in the midst of a voxel giving a signal value that is a mixture of the two. We propose a method to restore the ideal boundary by splitting a voxel into subvoxels and reapportioning the signal into the subvoxels. Each voxel is divided by nearest neighbor interpolation. The gray level of each subvoxel is considered as “material” able to move between subvoxels but not between voxels. A partial differential equation is written to allow the material to flow towards the highest gradient direction, creating a “reverse” diffusion process. Flow is subject to constraints that tend to create step edges. Material is conserved in the process thereby conserving signal. The method proceeds until the flow decreases to a low value. To test the method, synthetic images were downsampled to simulate the partial volume artifact and restored. Corrected images were remarkably closer both visually and quantitatively to the original images than those obtained from common interpolation methods: on simulated data standard deviation of the errors were 3.8%, 6.6%, and 7.1% of the dynamic range for the proposed method, bicubic, and bilinear interpolation, respectively. The method was relatively insensitive to noise. On gray level, scanned text, MRI physical phantom, and brain images, restored images processed with the new method were visually much closer to high-resolution counterparts than those obtained with common interpolation methods.
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institution Kabale University
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spelling doaj-art-c8c2514c1d444fd9a4f62169b3848e372025-02-03T01:01:07ZengWileyInternational Journal of Biomedical Imaging1687-41881687-41962006-01-01200610.1155/IJBI/2006/9209292092Partial Volume Reduction by Interpolation with Reverse DiffusionOlivier Salvado0Claudia M. Hillenbrand1David L. Wilson2Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, USADepartment of Radiological Sciences, St. Jude Children's Research Hospital, Memphis, TN 38105, USADepartment of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, USAMany medical images suffer from the partial volume effect where a boundary between two structures of interest falls in the midst of a voxel giving a signal value that is a mixture of the two. We propose a method to restore the ideal boundary by splitting a voxel into subvoxels and reapportioning the signal into the subvoxels. Each voxel is divided by nearest neighbor interpolation. The gray level of each subvoxel is considered as “material” able to move between subvoxels but not between voxels. A partial differential equation is written to allow the material to flow towards the highest gradient direction, creating a “reverse” diffusion process. Flow is subject to constraints that tend to create step edges. Material is conserved in the process thereby conserving signal. The method proceeds until the flow decreases to a low value. To test the method, synthetic images were downsampled to simulate the partial volume artifact and restored. Corrected images were remarkably closer both visually and quantitatively to the original images than those obtained from common interpolation methods: on simulated data standard deviation of the errors were 3.8%, 6.6%, and 7.1% of the dynamic range for the proposed method, bicubic, and bilinear interpolation, respectively. The method was relatively insensitive to noise. On gray level, scanned text, MRI physical phantom, and brain images, restored images processed with the new method were visually much closer to high-resolution counterparts than those obtained with common interpolation methods.http://dx.doi.org/10.1155/IJBI/2006/92092
spellingShingle Olivier Salvado
Claudia M. Hillenbrand
David L. Wilson
Partial Volume Reduction by Interpolation with Reverse Diffusion
International Journal of Biomedical Imaging
title Partial Volume Reduction by Interpolation with Reverse Diffusion
title_full Partial Volume Reduction by Interpolation with Reverse Diffusion
title_fullStr Partial Volume Reduction by Interpolation with Reverse Diffusion
title_full_unstemmed Partial Volume Reduction by Interpolation with Reverse Diffusion
title_short Partial Volume Reduction by Interpolation with Reverse Diffusion
title_sort partial volume reduction by interpolation with reverse diffusion
url http://dx.doi.org/10.1155/IJBI/2006/92092
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AT claudiamhillenbrand partialvolumereductionbyinterpolationwithreversediffusion
AT davidlwilson partialvolumereductionbyinterpolationwithreversediffusion