Combination of 3D MRI and connectivity analysis in structural evaluation of cancellous bone in rat proximal femur.

Three dimensional (3-D) magnetic resonance (MR) microimaging combined with connectivity analysis was tested in the study of the structure of cancellous bone. MR microimaging was performed in vitro with an average resolution of 202035 microm. A 3-D connectivity analysis was used to model the trabecular bone as a network consisting of nodes and struts. Size distribution curves of these two structural elements and the interconnectivity of nodes was used to estimate the cancellous structure. The analysis suggested the occurrence of two simultaneous network structures in cancellous bone differed by the size of details. The degradative effect of ostcopenia is found to be slightly different in these two subsystems. Interconnectivity is seen to increase with the size of a node and the expected loss of connectivity due to ostcopenia is observed. The method described offers a new way in the topological estimation of interconnected medium.