Detection of maturity and ligament injury using magic angle directional imaging
File(s)MRM 2019 - accepted preprint.pdf (628.01 KB)
Accepted version
Author(s)
Type
Journal Article
Abstract
Purpose: To investigate whether magnetic field–related anisotropies of collagen may be correlated with postmortem findings in animal models.
Methods: Optimized scan planning and new MRI data‐processing methods were proposed and analyzed using Monte Carlo simulations. Six caprine and 10 canine knees were scanned at various orientations to the main magnetic field. Image intensities in segmented voxels were used to compute the orientation vectors of the collagen fibers. Vector field and tractography plots were computed. The Alignment Index was defined as a measure of orientation distribution. The knees were subsequently assessed by a specialist orthopedic veterinarian, who gave a pathological diagnosis after having dissected and photographed the joints.
Results: Using 50% less scans than reported previously can lead to robust calculation of fiber orientations in the presence of noise, with much higher accuracy. The 6 caprine knees were found to range from very immature (< 3 months) to very mature (> 3 years). Mature specimens exhibited significantly more aligned collagen fibers in their patella tendons compared with the immature ones. In 2 of the 10 canine knees scanned, partial cranial caudal ligament tears were identified from MRI and subsequently confirmed with encouragingly high consistency of tractography, Alignment Index, and dissection results.
Conclusion: This method can be used to detect injury such as partial ligament tears, and to visualize maturity‐related changes in the collagen structure of tendons. It can provide the basis for new, noninvasive diagnostic tools in combination with new scanner configurations that allow less‐restricted field orientations.
Methods: Optimized scan planning and new MRI data‐processing methods were proposed and analyzed using Monte Carlo simulations. Six caprine and 10 canine knees were scanned at various orientations to the main magnetic field. Image intensities in segmented voxels were used to compute the orientation vectors of the collagen fibers. Vector field and tractography plots were computed. The Alignment Index was defined as a measure of orientation distribution. The knees were subsequently assessed by a specialist orthopedic veterinarian, who gave a pathological diagnosis after having dissected and photographed the joints.
Results: Using 50% less scans than reported previously can lead to robust calculation of fiber orientations in the presence of noise, with much higher accuracy. The 6 caprine knees were found to range from very immature (< 3 months) to very mature (> 3 years). Mature specimens exhibited significantly more aligned collagen fibers in their patella tendons compared with the immature ones. In 2 of the 10 canine knees scanned, partial cranial caudal ligament tears were identified from MRI and subsequently confirmed with encouragingly high consistency of tractography, Alignment Index, and dissection results.
Conclusion: This method can be used to detect injury such as partial ligament tears, and to visualize maturity‐related changes in the collagen structure of tendons. It can provide the basis for new, noninvasive diagnostic tools in combination with new scanner configurations that allow less‐restricted field orientations.
Date Issued
2019-09-01
Date Acceptance
2019-04-10
Citation
Magnetic Resonance in Medicine, 2019, 82 (3), pp.1041-1054
ISSN
0740-3194
Publisher
Wiley
Start Page
1041
End Page
1054
Journal / Book Title
Magnetic Resonance in Medicine
Volume
82
Issue
3
Copyright Statement
© 2019 International Society for Magnetic Resonance in Medicine. This is the accepted version of the following article: Chappell, KE, Brujic, D, Van Der Straeten, C, et al. Detection of maturity and ligament injury using magic angle directional imaging. Magn Reson Med. 2019; 82: 1041– 1054, which has been published in final form at https://doi.org/10.1002/mrm.27794
Sponsor
Department Of Trade & Industry (DTI)
Identifier
https://onlinelibrary.wiley.com/doi/full/10.1002/mrm.27794
Grant Number
TP/7/SEN/6/I/M1575C
Subjects
Science & Technology
Life Sciences & Biomedicine
Radiology, Nuclear Medicine & Medical Imaging
collagen
magic angle effect
musculoskeletal imaging
COLLAGEN FIBRILS
MRI
TENDON
ORIENTATION
ANISOTROPY
TRACKING
FIELD
collagen
magic angle effect
musculoskeletal imaging
Animals
Collagen
Dogs
Goats
Hindlimb
Image Interpretation, Computer-Assisted
Ligaments
Magnetic Resonance Imaging
Ligaments
Hindlimb
Animals
Goats
Dogs
Collagen
Image Interpretation, Computer-Assisted
Magnetic Resonance Imaging
0903 Biomedical Engineering
Nuclear Medicine & Medical Imaging
Publication Status
Published
Date Publish Online
2019-05-12