penMesh--Monte Carlo radiation transport simulation in a triangle mesh geometry.
We have developed a general-purpose Monte Carlo simulation code, called penMesh, that combines the accuracy of the radiation transport physics subroutines from PENELOPE and the flexibility of a geometry based on triangle meshes. While the geometric models implemented in most general-purpose codes--such as PENELOPE's quadric geometry--impose some limitations in the shape of the objects that can be simulated, triangle meshes can be used to describe any free-form (arbitrary) object. Triangle meshes are extensively used in computer-aided design and computer graphics. We took advantage of the sophisticated tools already developed in these fields, such as an octree structure and an efficient ray-triangle intersection algorithm, to significantly accelerate the triangle mesh ray-tracing. A detailed description of the new simulation code and its ray-tracing algorithm is provided in this paper. Furthermore, we show how it can be readily used in medical imaging applications thanks to the detailed anatomical phantoms already available. In particular, we present a whole body radiography simulation using a triangulated version of the anthropomorphic NCAT phantom. An example simulation of scatter fraction measurements using a standardized abdomen and lumbar spine phantom, and a benchmark of the triangle mesh and quadric geometries in the ray-tracing of a mathematical breast model, are also presented to show some of the capabilities of penMesh.
Institut de Tècniques Energètiques, Universitat Politècnica de Catalunya, 08028 Barcelona, Spain. andreu.badalsoler@fda.hhs.gov
Andreu
A
Badal
Iacovos
I
Kyprianou
Diem Phuc
DP
Banh
Aldo
A
Badano
Josep
J
Sempau
D003198:Computer Simulation; D020342:Finite Element Analysis; D006801:Humans; D008954:Models, Biological; D009010:Monte Carlo Method; D019047:Phantoms, Imaging; D011829:Radiation Dosage; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D012542:Scattering, Radiation; D012984:Software; D012986:Software Validation; D051598:Whole Body Imaging / Q000295:instrumentation / Q000379:methods*