Comparison of Synchrotron Radiation Based Propagation Phase Contrast Imaging and Conventional Micro-computed Tomography for Assessing Intervertebral Discs and Endplates in A Murine Model

STUDY DESIGN The synchrotron radiation based micro-CT (SRμCT) and micro-CT (μCT) were applied to comparatively assess the intervertebral disc (IVD) and endplate (EP). OBJECTIVE To explore a new approach to evaluate the detailed structure of the IVD and EP during maturation and aging in a murine model. SUMMARY OF BACKGROUND DATA To date, methods to observe the morphological changes in the IVD and EP from rodent have been relatively limited. SRμCT has been recognized as a potential way to visualize the structures containing sclerous and soft tissue. Our study focused on comparing the capacity of SRμCT and μCT in evaluating the detailed structure of the IVD and EP. METHODS Both SRμCT and μCT were performed to depict the structure of spinal tissue from 4-month-old mice. Then, the imaging quality was evaluated in the 3D reconstructed model. Further, the changes in the EP and IVD during the maturation and aging process were assessed morphologically and quantitatively using SRμCT. RESULTS The 3D reconstructed model of the EP from both μCT and SRμCT provided detailed information on its inner structure. However, the IVD was only depicted using SRμCT. Multi-angle observations of the 3D structure of EP and IVD from mice of different ages (15 days, 2 months, 4 months and 18 months) were dynamically performed by SRμCT. Quantitative evaluations indicated that the total volume of EP and IVD, the average height of IVD and the canal-total volume ratio of EP increased from 15-day-old mice to 4-month-old mice and decreased in 18-month-old mice. CONCLUSIONS The EP and IVD were clearly visualized using SRμCT. Compared to μCT, SRμCT provided a better ultra-high resolution image of soft tissue and hard tissue simultaneously, which makes it a promising approach for the noninvasive study of disc degeneration. LEVEL OF EVIDENCE N/A.