Demonstration of three-dimensional imaging with a germanium Compton camera

McKisson, J.; Haskins, P.S.; Phillips, Gary W.; King, S.E.; August, R.A.; Piercey, R. B.; Mania, R.C.

doi:10.1109/23.322888

Cited by 16 publications

(5 citation statements)

References 11 publications

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“…The interception of several cone surfaces allows one to obtain the radiotracer distribution in two dimensions (or even three dimensions (McKisson et al 1994)) with a single compact detector. Equation (1) represents the ideal case, while in reality the Compton cone reconstruction is affected by the so-called Doppler broadening (Ordonez et al 1997).…”

Section: Introductionmentioning

confidence: 99%

Compton camera study for high efficiency SPECT and benchmark with Anger system

et al. 2017

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Single photon emission computed tomography (SPECT) is at present one of the major techniques for non-invasive diagnostics in nuclear medicine. The clinical routine is mostly based on collimated cameras, originally proposed by Hal Anger. Due to the presence of mechanical collimation, detection efficiency and energy acceptance are limited and fixed by the system's geometrical features. In order to overcome these limitations, the application of Compton cameras for SPECT has been investigated for several years. In this study we compare a commercial SPECT-Anger device, the General Electric HealthCare Infinia system with a High Energy General Purpose (HEGP) collimator, and the Compton camera prototype under development by the French collaboration CLaRyS, through Monte Carlo simulations (GATE-GEANT4 Application for Tomographic Emission-version 7.1 and GEANT4 version 9.6, respectively). Given the possible introduction of new radio-emitters at higher energies intrinsically allowed by the Compton camera detection principle, the two detectors are exposed to point-like sources at increasing primary gamma energies, from actual isotopes already suggested for nuclear medicine applications. The Compton camera prototype is first characterized for SPECT application by studying the main parameters affecting its imaging performance: detector energy resolution and random coincidence rate. The two detector performances are then compared in terms of radial event distribution, detection efficiency and final image, obtained by gamma transmission analysis for the Anger system, and with an iterative List Mode-Maximum Likelihood Expectation Maximization (LM-MLEM) algorithm for the Compton reconstruction. The results show for the Compton camera a detection efficiency increased by a factor larger than an order of magnitude with respect to the Anger camera, associated with an enhanced spatial resolution for energies beyond 500 keV. We discuss the advantages of Compton camera application for SPECT if compared to present commercial Anger systems, with particular focus on dose delivered to the patient, examination time, and spatial uncertainties.

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Section: Introductionmentioning

confidence: 99%

Compton camera study for high efficiency SPECT and benchmark with Anger system

et al. 2017

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“…Single-sided 3D imaging has been demonstrated in Compton cameras by taking advantage of the parallax effect [13]. However, parallax techniques require a large solid angle coverage to function as a modality at all, whereas our method only requests solid angle coverage to increase efficiency.…”

Section: Introductionmentioning

confidence: 99%

Single-View 3-D Reconstruction of Correlated Gamma-Neutron Sources

Monterial

Marleau

Pozzi

2017

IEEE Trans. Nucl. Sci.

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Abstract-We describe a new method of 3D image reconstruction of neutron sources that emit correlated gammas (e.g. Cf-252, Am-Be). This category includes a vast majority of neutron sources important in nuclear threat search, safeguards and non-proliferation. Rather than requiring multiple views of the source this technique relies on the source's intrinsic property of coincidence gamma and neutron emission. As a result only a single-view measurement of the source is required to perform the 3D reconstruction. In principle, any scatter camera sensitive to gammas and neutrons with adequate timing and interaction location resolution can perform this reconstruction. Using a neutron double scatter technique, we can calculate a conical surface of possible source locations. By including the time to a correlated gamma we further constrain the source location in three-dimensions by solving for the source-to-detector distance along the surface of said cone. As a proof of concept we applied these reconstruction techniques on measurements taken with the the Mobile Imager of Neutrons for Emergency Responders (MINER). Two Cf-252 sources measured at 50 and 60 cm from the center of the detector were resolved in their varying depth with average radial distance relative resolution of 26%. To demonstrate the technique's potential with an optimized system we simulated the measurement in MCNPX-PoliMi assuming timing resolution of 200 ps (from 2 ns in the current system) and source interaction location resolution of 5 mm (from 3 cm). These simulated improvements in scatter camera performance resulted in radial distance relative resolution decreasing to an average of 11%.

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“…Compton cameras have been used for gamma-ray astronomy [1], medical imaging [2]- [5], industrial use [6], and nuclear waste management [7]; Phillips has concisely reviewed their history up to 1994 [8].…”

Section: Introductionmentioning

confidence: 99%

Analytical image reconstruction of cone-beam projections from limited-angle Compton camera data

Tomitani¹,

Hirasawa²

2003

IEEE Trans. Nucl. Sci.

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Since the integration of gamma-rays on a cone is measured with Compton cameras, some sort of image reconstruction method is necessary. Parra developed an analytical reconstruction algorithm based on a spherical harmonics expansion of projection data that covers the entire scattering-angle range. The measurable scattering angle range is limited due to the electrical noise of the detector and to the finite detector configuration. In this article, a reconstruction algorithm from the projection of a limited scattering angle range is presented. The algorithm was based on an inversion of the summed backprojection. The variance of the reconstructed image of a uniform source was calculated and found proportional to the third power of the number of expansion terms. Thus, window functions were introduced to suppress noise at the cost of spatial resolution. The dependency of the spatial resolution on the number of expansion terms was analyzed. From this, the dependency of the variance on the spatial resolution was found to be variance (spatial resolution) 3 .

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Demonstration of three-dimensional imaging with a germanium Compton camera

Cited by 16 publications

References 11 publications

Compton camera study for high efficiency SPECT and benchmark with Anger system

Compton camera study for high efficiency SPECT and benchmark with Anger system

Single-View 3-D Reconstruction of Correlated Gamma-Neutron Sources

Analytical image reconstruction of cone-beam projections from limited-angle Compton camera data

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