The Center for Molecular and Biomolecular Imaging provided pilot funding for Prof. Anuj Kapadia’s collaborative research into Neutron Stimulated Emission Computed Tomography (NSECT) spectroscopic examinations of tissue using the Spallation Neutron Sources (SNS) at Oak Ridge National Labs (ORNL).
a) SNR: Background noise from broad-spectrum beam was not found to be a significant concern. While there was a significant level of background noise observed in the spectrum, it was easily eliminated by pulsing the gamma detectors with respect to the neutron beam.
b) Detection Sensitivity: Despite the presence of high background noise the detection limit was found to be better by at least a factor of 2. Further, data acquisition with the improved sensitivity could be achieved in very short time durations (minutes instead of hours) due to the significantly higher neutron fluxes available at SNS.
c) Detector Damage: While the specialized HPGe gamma-detectors used in the experiment are ordinarily susceptible to damage from fast neutrons, simulation results showed that a combination of lead and borated plastic detector shielding was sufficient to limit fast-neutron incidence on the detectors to allow safe use without significant damage.
The research led to a full collaboration between Prof. Kapadia and ORNL, culminating in a federally funded research project (Department of Defense Award BC133814 – In-vivo Diagnosis of Breast Cancer using Neutron and Gamma Stimulated Emission Computed Tomography).
A.J. Kapadia, F.X. Gallmeier, E.B. Iverson, and P.D. Ferguson, “Detection of iron overload with the ORNL Spallation Neutron Source: An MCNPX simulation study,” IEEE Nuclear Science Symposium, Medical Imaging Conference, Dresden, Germany, 4972-4975 (2008).
A.J. Kapadia, B.P. Harrawood, and G.D. Tourassi, “Validationi of a GEANT4 simulation of neutron stimulated emission computed tomography,” SPIE Symposium on Medical Imaging, San Diego, CA, 69133H (2008).
A.J. Kapadia, B.P. Harrawood, and G.D. Tourassi, “GEANT4 simulation of NSECT for detection of iron overload in the liver,” SPIE Symposium on Medical Imaging, San Diego, CA, 691309 (2008).
G.A. Agasthya and A.J. Kapadia, “A Technique to Locate Stored Iron in the Liver Using Attenuation Correction for Neutron Stimulated Emission Computed Tomography,” IEEE Nuclear Science Symposium and Medical Imaging Conference, Orlando, FL (2009).
A.J. Kapadia, “Neutron Stimulated Emission Computed Tomography: A New Technique for Spectroscopic Medical Imaging”, Neutron Imaging and Applications, Anderson, McGreevy, Bilheux, Eds: Springer (2009).
A.J. Kapadia, G.A. Agasthya, and G.D. Tourassi, “Detection of iron overload through neutron stimulated emission computed tomography: a sensitivity analysis study,” SPIE Symposium on Medical Imaging, Orlando, FL, 725811 (2009).
G.A. Agasthya, B.P. Harrawood, J.P. Shah, and A.J. Kapadia, “Sensitivity analysis for liver iron measurement through neutron stimulated emission computed tomography: a Monte Carlo study in GEANT4”, Phys Med Biol, 57, 113-126 (2012).
R.S. Viana, A.G. Agasthya, H. Yoriyaz, and A.J. Kapadia, “3D element imaging using NSECT for the detection of renal cancer: a simulation study in MCNP”, Phys Med Biol, 58, 5867-5883 (2013).