Inveon analysis workstation

The tibia in rats with different interventions were obtained and fixed with 4% paraformaldehyde. And then, we used the microCT manufactured by Siemens (Berlin, Germany) to reconstruct the bone structure and calculate the bone parameters with Inveon analysis workstation. The bone parameters including bone volume/total volume (BV/TV), trabecular thickness (Tb.Th), trabecular number (Tb.N), and trabecular separation (Tb.Sp) were used for bone quality calculation.

The femur specimens were sampled and fixed in 10 % buffered neutral formalin solution until examination. The specimens were scanned by Inveon micro PET/CT manufactured by Siemens (Berlin, Germany) at a voltage of 60 kV and a current of 400uA, with entire scan length of 20 mm in a spatial resolution of 10 μm used for animal experimental studies and reconstructed using Inveon analysis workstation. The micro CT diagnosis standard for femoral head necrosis is fracture of the trabecula, cyst degeneration, sclerosis band or flattened shape of the femoral head. Two independent researchers made the diagnosis blindedly, if there was disagreement, consensus was reached by a third person. 1 mm below the center of the epiphyseal line with a total of 50 slices was chosen as the region of interest (ROI) for the analysis and comparison of trabecula paramenters. On the cross-section the cortical bone and spongy bone was separated manually by auto trace, later the trabeculae and the bone marrow was separated by the threshold function (Fig. 2). After that, the bone volume/total volume(BV/TV), bone surface area/bone volume, trabecular thickness, trabecular number, Trabecular spacing, trabecular pattern factor, cortical wall thickness and bone mineral density (BMD) in the ROI were computed respectively by the workstation.Fig. 2

The region of interest chosen and the identification of trabecula