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

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. 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. 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 mm[3] and 8242.8 mm[2] using 3D-Doctor software, which were agreement with those obtained from Brunn's formula. Stereolithographic biomodeling is a state-of-the-art and reliable method of visualizing anatomoclinical structures and abnormalities

Quantitative analysis of myelinated axons of commissural fibers in the cat brain

There are limited data related to the number of commissural axons found in various species. Although the corpus callosum has been investigated in cat, there are no data on the number of its myelinated axons. Additionally, the number of myelinated axons of anterior, posterior and habenular commissures are not documented for the cat. Therefore, we aimed to examine the topographic distribution and regional numerical differences of myelinated axons in encephalic commissures of the cat. This study was carried out at the Faculty of Medicine, Hacettepe University, Ankara, Turkey, from March 2003 to July 2003. The myelinated axons of the encephalic commissures of one cat were counted in this study. In parts of the corpus callosum, a statistically significant difference was found between rostrum and genu, rostrum and truncus, genu and truncus, genu and splenium and truncus and splenium. However, no statistically significant difference was found between rostrum and splenium. When comparing the number of myelinated axons of anterior, posterior and habenular commissures, statistically significant differences were found between anterior and habenular commissures, and between posterior and habenular commissures. No statistically significant difference was found between anterior and posterior commissures. These numerical data, evaluated by quantitative analytical statistical methods, might be useful in filling the lack of information on the mean numbers of myelinated axons of different commissures. Knowledge of the number of myelinated axons in different parts of the corpus callosum may also be very important when performing surgical procedures of the corpus callosum, such as commissurectomies