GEANT4 simulation of NSECT for detection of iron overload in the liver


Journal Article

Neutron stimulated emission computed tomography (NSECT) is being proposed as a non-invasive technique to diagnose iron overload in humans. It uses inelastic scatter interactions between incident neutrons and iron nuclei to stimulate gamma-ray emission from iron. Tomographic detection of the emitted gamma-rays yields information about the concentration and spatial distribution of iron in the liver. Early proof-of-concept experiments have shown that NSECT has the potential to quantify clinical quantities of liver iron overload through single-position spectroscopy. However, a tomography application for patient diagnosis has never been tested. This work uses a Monte-Carlo simulation of a tomographic NSECT system to investigate the feasibility of imaging the spatial distribution of liver iron through tomography. A simulation of an NSECT system has been designed in GEANT4 and used to tomographically scan a simulated human liver phantom with high-concentration iron lesions. Images are reconstructed with the MLEM algorithm and analyzed for pixel values within iron regions to determine the statistical significance of detection. Analysis results indicate that a wet iron concentration of 3 mg/g can be detected in surrounding liver tissue with p-value ≤ 0.0001 for neutron exposure corresponding to a radiation dose of 0.72 mSv. The research performed here demonstrates that NSECT has the ability to image clinically relevant distributions of iron through tomographic scanning.

Full Text

Duke Authors

Cited Authors

  • Kapadia, AJ; Harrawood, BP; Tourassi, GD

Published Date

  • May 19, 2008

Published In

Volume / Issue

  • 6913 /

International Standard Serial Number (ISSN)

  • 1605-7422

Digital Object Identifier (DOI)

  • 10.1117/12.773245

Citation Source

  • Scopus