The 90th percentile female tetrahedral-type phantom. Tetrahedral-type phantoms are a progression of surface-type phantoms where surface meshes are replaced with volume tetrahedrons. Tetrahedral-type geometry is easily incorporated in Monte Carlo codes and leads to faster radiation transport calculations, while preserving the original complexity of surface phantoms. Shown here is the female tetrahedral-type phantom used in the calculations. In this view, the skin, muscles, and residual tissues are hidden to showcase internal anatomy structures. The right side of the phantom was visualized with smooth surfaces, while the left side was visualized as a surface with edges, showing the tetrahedrons that comprise the different region

 A close up of the midsection of the tetrahedral-type phantoms. Tetrahedral-type phantoms are constructed with volumes filled with varying sized tetrahedrons. In the image, the lines on the organs represent the various tetrahedrons used to define that volume. Volumes and regions defined in this manner depend only on the size of the tetrahedrons, of which there is no real limitation. While in large organs finely detailed tetrahedrons may not be needed, small volumes such as mucosa linings benefit greatly with this phantom type and can be modeled at the micrometer level.