Fig. 3

Mouse 2, distal thoracic spine (male mouse, 11.5 weeks old at MRI, specimen X-ray, and histology) A-E: Soft X-ray images. A, B: specimen, C-E: 3.5 weeks, 7.5 weeks, 12 weeks after birth respectively. Wedging vertebrae at the distal thoracic spine are demarcated by high-density lines, but the intervertebral structures involved are unclear. F: Histology, × 40. Malformed vertebrae have more trabecular bone on the concave side and more bone marrow on the convex side. GPs of the malformed vertebrae are meandering and irregular in thickness, containing mostly hypertrophic chondrocytes, and partially merged with adjacent GPs (arrowhead). The CEP and BM are observed in the space between these irregular GPs, but the NP is lacking. On both the concave and convex sides of the curve, the thick FT of the costovertebral joint capsule covers the surface of the malformed segment. G: T1-weighted MR image. Malformed vertebrae are surrounded by a low-intensity band, which corresponds with the irregular width of the GP observed via histology. The convex side with rich bone marrow was observed at a higher intensity. H: T2-weighted MR image. The caudal intervertebral space is brightly intense, which is consistent with the presence of the NP and AF according to histology(*)