TY - JOUR
T1 - Theory of MRI contrast in the annulus fibrosus of the intervertebral disc
AU - Wright, Alexander C.
AU - Yoder, Jonathon H.
AU - Vresilovic, Edward J.
AU - Elliott, Dawn M.
N1 - Funding Information:
This work was supported by NIH Grants EB001427 and AR050052, and by a seed grant from the Penn Center for Musculoskeletal Disorders, Award Number P30AR050950 from the National Institute of Arthritis, Musculoskeletal and Skin Diseases. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institute of Arthritis, Musculoskeletal and Skin Diseases or the National Institutes of Health.
Publisher Copyright:
© 2016, ESMRMB.
PY - 2016/8/1
Y1 - 2016/8/1
N2 - Objective: Here we develop a three-dimensional analytic model for MR image contrast of collagen lamellae in the annulus fibrosus of the intervertebral disc of the spine, based on the dependence of the MRI signal on collagen fiber orientation. Materials and methods: High-resolution MRI scans were performed at 1.5 and 7 T on intact whole disc specimens from ovine, bovine, and human spines. An analytic model that approximates the three-dimensional curvature of the disc lamellae was developed to explain inter-lamellar contrast and intensity variations in the annulus. The model is based on the known anisotropic dipolar relaxation of water in tissues with ordered collagen. Results: Simulated MRI data were generated that reproduced many features of the actual MRI data. The calculated inter-lamellar image contrast demonstrated a strong dependence on the collagen fiber angle and on the circumferential location within the annulus. Conclusion: This analytic model may be useful for interpreting MR images of the disc and for predicting experimental conditions that will optimize MR image contrast in the annulus fibrosus.
AB - Objective: Here we develop a three-dimensional analytic model for MR image contrast of collagen lamellae in the annulus fibrosus of the intervertebral disc of the spine, based on the dependence of the MRI signal on collagen fiber orientation. Materials and methods: High-resolution MRI scans were performed at 1.5 and 7 T on intact whole disc specimens from ovine, bovine, and human spines. An analytic model that approximates the three-dimensional curvature of the disc lamellae was developed to explain inter-lamellar contrast and intensity variations in the annulus. The model is based on the known anisotropic dipolar relaxation of water in tissues with ordered collagen. Results: Simulated MRI data were generated that reproduced many features of the actual MRI data. The calculated inter-lamellar image contrast demonstrated a strong dependence on the collagen fiber angle and on the circumferential location within the annulus. Conclusion: This analytic model may be useful for interpreting MR images of the disc and for predicting experimental conditions that will optimize MR image contrast in the annulus fibrosus.
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U2 - 10.1007/s10334-015-0522-3
DO - 10.1007/s10334-015-0522-3
M3 - Article
C2 - 26755061
AN - SCOPUS:84954092146
VL - 29
SP - 711
EP - 722
JO - Magnetic Resonance Materials in Physics, Biology, and Medicine
JF - Magnetic Resonance Materials in Physics, Biology, and Medicine
SN - 0968-5243
IS - 4
ER -