Angle‐sensitive MRI for quantitative analysis of fiber‐network deformations in compressed cartilage. Issue 1 (28th May 2013)

• Record Type: Journal Article
• Authors: Garnov, Nikita; Busse, Harald; Gründer, Wilfried
• Is Part Of: Magnetic resonance in medicine. Volume 70:Issue 1(2013:Jul.)
• Page Start: 225
• Page End: 231
• Publication Date: 2013-05-28
• Subjects: Nuclear magnetic resonance -- Periodicals; Electron paramagnetic resonance -- Periodicals; 616.07548
• DOI: 10.1002/mrm.24795
• Languages: English
• ISSNs: 0740-3194

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <sec id="abs1-1" sec-type="section"> <title>Purpose</title> <p>To demonstrate the feasibility of a novel experimental method to quantitatively analyze fiber‐network deformation in compressed cartilage by angle‐sensitive magnetic resonance imaging (MRI) of cartilage.</p> </sec> <sec id="abs1-2" sec-type="section"> <title>Methods</title> <p>Three knee cartilage samples of an adult sheep were imaged in a high‐resolution MRI scanner at 7 T. Main fiber orientation and its "offset" from the direction perpendicular to the bone‐cartilage boundary were derived from MR images taken at different orientations with respect to <italic>B</italic><sub>0</sub>. Bending of the collagen fibers was determined from weight‐bearing MRI with the load (up to 1.0 MPa) applied over the whole sample surface. A "fascicle" model of the cartilage ultrastructure was assumed to analyze characteristic intensity variations in <italic>T</italic><sub>2</sub>‐weighted images under load.</p> </sec> <sec id="abs1-3" sec-type="section"> <title>Results</title> <p> <italic>T</italic> <sub>2</sub>‐weighted MR images showed a strong variation of the signal intensities with sample orientation. In the <italic>T</italic><sub>2</sub>‐weighted weight‐bearing series, regions of high signal intensity underwent shifts from the lateral to the central parts in all three cartilage samples. The bending of the collagen fibers was determined to be 27.2°, 35.4°, and 40.0° per MPa, respectively.</p> </sec> <sec id="abs1-4" sec-type="section"> <title>Conclusion</title> <p>Assuming a "fascicle" model, the presented MRI method provides quantitative measures of structural adjustments in compressed cartilage. Our preliminary analysis suggests that cartilage fiber deformation includes both bending and crimping.</p> </sec> </abstract>