Accelerating mesh-based Monte Carlo method on modern CPU architectures

Qianqian Fang,David R Kaeli

doi:10.1364/boe.3.003223

Abstract

In this report, we discuss the use of contemporary ray-tracing techniques to accelerate 3D mesh-based Monte Carlo photon transport simulations. Single Instruction Multiple Data (SIMD) based computation and branch-less design are exploited to accelerate ray-tetrahedron intersection tests and yield a 2-fold speed-up for ray-tracing calculations on a multi-core CPU. As part of this work, we have also studied SIMD-accelerated random number generators and math functions. The combination of these techniques achieved an overall improvement of 22% in simulation speed as compared to using a non-SIMD implementation. We applied this new method to analyze a complex numerical phantom and both the phantom data and the improved code are available as open-source software at http://mcx.sourceforge.net/mmc/.

Highlights

Near-infrared (NIR) light with wavelength between 600 and 1000 nm can penerate deep into the tissue [1], owning primarily to the relatively low optical absorption of human tissue chromorphores, namely oxy/deoxy-hemoglobin, lipids and water
Accurate and efficient numerical methods play an essential role in NIR-based techniques such as diffuse optical tomography (DOT) and fluorescence molecular tomography (FMT)
We quantitatively compare the proposed algorithms to demonstrate the benefits of using Streaming SIMD Extensions (SSE) acceleration

Summary

Introduction

Near-infrared (NIR) light with wavelength between 600 and 1000 nm can penerate deep into the tissue [1], owning primarily to the relatively low optical absorption of human tissue chromorphores, namely oxy/deoxy-hemoglobin, lipids and water. This remarkable characteristic makes NIR light a suitable candidate to probe deep tissue physiology such as angiogenesis and oxygen metabolism in a safe and non-invasive manner. The transport of low-energy NIR photons is highly nonlinear and exhibits a complex and diffusive pattern. Accurate and efficient numerical methods play an essential role in NIR-based techniques such as diffuse optical tomography (DOT) and fluorescence molecular tomography (FMT)

Methods

Results

Conclusion