Quantifying deformations and strains in human intervertebral discs using Digital Volume Correlation combined with MRI (DVC-MRI)
File(s)
Accepted version
Supporting information
Author(s)
Type
Journal Article
Abstract
Physical disruptions to intervertebral discs (IVDs) can cause mechanical changes that lead to degeneration and to low back pain which affects 75% of us in our lifetimes. Quantifying the effects of these changes on internal IVD strains may lead to better preventative strategies and treatments. Digital Volume Correlation (DVC) is a non-invasive technique that divides volumetric images into subsets, and measures strains by tracking the internal patterns within them under load. Applying DVC to MRIs may allow non-invasive strain measurements. However, DVC-MRI for strain measurements in IVDs has not been used previously. The purpose of this study was to quantify the strain and deformation errors associated with DVC-MRI for measurements in human IVDs.
Eight human lumbar IVDs were MRI scanned (9.4T) for a ‘zero-strain study’ (multiple unloaded scans to quantify noise within the system), and a loaded study (2mm axial compression). Three DVC methodologies: Fast-Fourier transform (FFT), direct correlation (DC), and a combination of both FFT and DC approaches were compared with subset sizes ranging from 8 to 88 voxels to establish the optimal DVC methodology and settings which were then used in the loaded study.
FFT+DC was the optimal method and a subset size of 56 voxels (2520 micrometers) was found to be a good compromise between errors and spatial resolution. Displacement and strain errors did not exceed 28 µm and 3000 microstrain, respectively.
These findings demonstrate that DVC-MRI can quantify internal strains within IVDs non-invasively and accurately. The method has unique potential for assessing IVD strains within patients.
Eight human lumbar IVDs were MRI scanned (9.4T) for a ‘zero-strain study’ (multiple unloaded scans to quantify noise within the system), and a loaded study (2mm axial compression). Three DVC methodologies: Fast-Fourier transform (FFT), direct correlation (DC), and a combination of both FFT and DC approaches were compared with subset sizes ranging from 8 to 88 voxels to establish the optimal DVC methodology and settings which were then used in the loaded study.
FFT+DC was the optimal method and a subset size of 56 voxels (2520 micrometers) was found to be a good compromise between errors and spatial resolution. Displacement and strain errors did not exceed 28 µm and 3000 microstrain, respectively.
These findings demonstrate that DVC-MRI can quantify internal strains within IVDs non-invasively and accurately. The method has unique potential for assessing IVD strains within patients.
Date Issued
2020-03-26
Date Acceptance
2019-12-31
Citation
Journal of Biomechanics, 2020, 102, pp.1-7
ISSN
0021-9290
Publisher
Elsevier BV
Start Page
1
End Page
7
Journal / Book Title
Journal of Biomechanics
Volume
102
Copyright Statement
© 2020 Elsevier Ltd. All rights reserved. This manuscript is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International Licence http://creativecommons.org/licenses/by-nc-nd/4.0/
Identifier
https://www.sciencedirect.com/science/article/pii/S0021929020300075?via%3Dihub
Subjects
Science & Technology
Life Sciences & Biomedicine
Technology
Biophysics
Engineering, Biomedical
Engineering
Digital Volume Correlation (DVC)
MRI
Intervertebral Disc (IVD)
Internal strain
Zero-strain study
LOW-BACK-PAIN
AUGMENTED VERTEBRAE
BONE
COMPRESSION
TISSUE
UNCERTAINTIES
DEGENERATION
DISPLACEMENT
RESOLUTION
ACCURACY
Digital Volume Correlation (DVC)
Internal strain
Intervertebral Disc (IVD)
MRI
Zero-strain study
0903 Biomedical Engineering
0913 Mechanical Engineering
1106 Human Movement and Sports Sciences
Biomedical Engineering
Publication Status
Published
Article Number
109604
Date Publish Online
2020-01-03