DEVELOPMENT OF A CANCELLOUS BONE STRUCTURAL MODEL BY STEREOLITHOGRAPHY FOR ULTRASOUND CHARACTERIZATION OF THE CALCANEUS

A novel method for the development of a user-defined structural model simulating cancellous bone of the human calcaneus is described using s tereolithography (SL). The digital image of a cancellous bone section was modified by skeletonisation and dilation to produce a structural m odel of uniform wall thickness, determined by the resolution of the st ereolithography system. Six SL models were produced using the same dat a file. The SL models were assessed using the McCue CUBAclinical ultra sound bone densitometer. The broadband ultrasound attenuation (BUA) an d velocity (VOS) values obtained were commensurate with the commercial phantom provided with the CUBAclinical system. The intra-and inter-sa mple variability for the six SL models were similar at 5% for BUA and 2.5% for VOS. Stereolithography offers the potential to firstly, simul ate perforation and thinning of cancellous bone associated with osteop orosis; and secondly, to evaluate the dependence of ultrasonic and mec hanical parameters upon cancellous bone structure. (C) 1997 IPEM. Publ ished by Elsevier Science Ltd.