The reproduction accuracy for stereolithographic model of the thyroid gland derived from the visible human dataset

OBJECTIVE: To investigate reproduction accuracy of the rapid prototyping technique by comparing 3-dimensional computer-aided design (CAD) (virtual) model with stereolithographic (solid) replica of the thyroid gland.

METHODS: The Visible Human Dataset was used as the input imaging data. The Surfdriver software package was applied on these images to reconstruct the thyroid gland as 3-dimensional Data Exchange File (DXF) models. These models were post-processed in Cinema 4D and 3D-Doctor software for Virtual Reality Modeling Language (VRML) and Standard Triangulation Language (STL) formats. Stereolithographic replica was manufactured in the rapid prototyping machine using STL format. This study was conducted between June 1-30, 2008 at the Department of Anatomy, Hacettepe University, Ankara, Turkey. An excellent agreement was found in comparing the maximal dimensions of the CAD model of the thyroid gland and the corresponding stereolithographic model. Visual and tactile examination of the thyroid gland model allowed correct depiction of the thyroid gland anatomy. The accuracy of the stereolithographic model was attained by comparing wih the CAD model.

RESULTS: Dimensional analysis showed that an average difference between the measurements on the virtual and the solid model was 0.09 mm (p=0.06), ranging from 0.07-0.92 mm. Thyroid volume and surface area were calculated to be 25393.9 mm3 and 8242.8 mm2 using 3D-Doctor software, which were agreement with those obtained from Brunn's formula.

CONCLUSION: Stereolithographic biomodeling is a state-of-the-art and reliable method of visualizing anatomoclinical structures and abnormalities.