Quantitative comparison of freeware software for bone mesh from DICOM files.
Musculo-skeletal modelling, 3D printing of bone models and also custom design of relevant prostheses starts from accurate STL files. These are obtained from medical imaging after careful segmentation and 3D reconstruction using specialized software, but most of these are very expensive. The aim of the present study is to assess and compare alternative software available for free. Three freeware software were selected from the most popular, and one standard platform was made available at the institute of the authors. Using each of these four software and starting from available DICOM files obtained previously by a CT scanner, three different bone models were reconstructed from each of five different human anatomical areas for a total of 60 bone model reconstructions. A young radiographer performed the bone reconstruction without specific technical training. 3D spatial matching of corresponding anatomical models was also performed to determine distance-maps for the assessment of final surface quality. In all four software many valuable features were available, with minimum differences, and bone models of good quality were obtained. Large differences in file sizes (mean range over the five anatomical models 66-338) and in the number of triangles (870-1350 thousands) were found, with triangles for MByte ratio ranging from about 4 to 20 thousands. The distance-map analysis revealed that root mean square deviation averaged over the five anatomical models ranged from 0.13 to 2.21 mm for the six spatial matches between the four software. These software are suitable for 3D bone model reconstruction, and do not require special training, and as such these can open up opportunities for biomechanical modelling and medical education.