3D grating-based X-ray phase-contrast computed tomography for high-resolution quantitative assessment of cartilage: An experimental feasibility study with 3T MRI, 7T MRI and biomechanical correlation

PLoS One. 2019 Feb 14;14(2):e0212106. doi: 10.1371/journal.pone.0212106. eCollection 2019.

Abstract

Objective: Aim of this study was, to demonstrate the feasibility of high-resolution grating-based X-ray phase-contrast computed tomography (PCCT) for quantitative assessment of cartilage.

Materials and methods: In an experimental setup, 12 osteochondral samples were harvested from n = 6 bovine knees (n = 2 each). From each knee, one cartilage sample was degraded using 2.5% Trypsin. In addition to PCCT and biomechanical cartilage stiffness measurements, 3T and 7T MRI was performed including MSME SE T2 and ME GE T2* mapping sequences for relaxationtime measurements. Paired t-tests and receiver operating characteristics (ROC) curves were used for statistical analyses.

Results: PCCT provided high-resolution images for improved morphological cartilage evaluation as compared to 3T and 7T MRI. Quantitative analyses revealed significant differences between the superficial and the deep cartilage layer for T2 mapping as well as for PCCT (P<0.05). No significant difference was detected for PCCT between healthy and degraded samples (P>0.05). MRI and stiffness measurements showed significant differences between healthy and degraded osteochondral samples. Accuracy in the prediction of cartilage degradation was excellent for MRI and biomechanical analyses.

Conclusion: In conclusion, high-resolution grating-based X-ray PCCT cartilage imaging is feasible. In addition to MRI and biomechanical analyses it provides complementary, water content independent, information for improved morphological and quantitative characterization of articular cartilage ultrastructure.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cartilage / cytology
  • Cartilage / diagnostic imaging*
  • Cartilage / metabolism*
  • Cattle
  • Feasibility Studies
  • Hindlimb / diagnostic imaging
  • Imaging, Three-Dimensional*
  • Magnetic Resonance Imaging / instrumentation
  • Magnetic Resonance Imaging / methods*
  • Phantoms, Imaging
  • Signal-To-Noise Ratio*
  • Tomography, X-Ray Computed / instrumentation
  • Tomography, X-Ray Computed / methods*

Grants and funding

This work was supported by the German Research Foundation (DFG) and the Technische Universitaet Muenchen within the funding programme Open Access Publishing to JH and PMJ. This work was supported by grants of the Deutsche Forschungsgemeinschaft (DFG WI 3686/4-1) to M. Wildgruber, by the Commission for Clinical Research, Technische Universitaet Muenchen (TUM), TUM School of Medicine, Munich, Germany (Project 8762152) to PMJ, by the Bundesministerium für Bildung und Forschung (BMBF 0315577C) to JH/ FP, by B. Braun- Stiftung (BBST-D-17-00070R1) to PMJ and by Arthrex GmbH (Munich, Germany) to PMJ. We further acknowledge financial support through the European Research Council (ERC, H2020, AdG 695045), the DFG Cluster of Excellence Munich-Centre for Advanced Photonics (MAP), the DFG Gottfried Wilhelm Leibniz program and the support of the TUM Institute for Advanced Study, funded by the German Excellence Initiative to JH/ FP. This work was carried out with the support of the Karlsruhe Nano Micro Facility (KNMF, www.kit.edu/knmf), a Helmholtz Research Infrastructure at Karlsruhe Institute of Technology (KIT) to JH/ FP. Dimitrios C. Karampinos and Peter B. Noël are receiving grant support from Philips. The grant support from Philips was not for this specific study. The study we performed was entirely independent of the funding. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.