Compton Cameras for Nuclear Medical Imaging

Rogers, W.L.; Clinthorne, N.H.; Bolozdynya, A.

doi:10.1016/b978-012744482-6/50022-3

Cited by 11 publications

(3 citation statements)

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“…In applications such as emission tomography with Compton camera, the noise level is usually high and the full overdetermined transform must actually be used for image reconstruction. Moreover, noise statistics as well as factors governing system performance such as Doppler broadening or polarization [22] should be included in the forward and adjoint problem. Resulting algorithms based on conical Radon transforms (which require binning of Compton camera raw data) should be compared with list mode EM reconstruction algorithms [44] that work without data binning.…”

Section: Discussionmentioning

confidence: 99%

“…The inversion of conical Radon transforms arises in single photon emission tomography (SPECT) using Compton cameras [22,23], as well as in other applications such as single scattering optical tomography [24]. In the context of SPECT with Compton cameras, the general radial weight that we consider in this paper allows to include the physically relevant effect of attenuation of photons.…”

Section: Introductionmentioning

confidence: 99%

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Variational regularization of the weighted conical Radon transform

Haltmeier

Schiefeneder

2018

Inverse Problems

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Recovering a function from integrals over conical surfaces recently got significant interest. It is relevant for emission tomography with Compton cameras and other imaging applications. In this paper, we consider the weighted conical Radon transform with vertices on the sphere. Opposed to previous works on conical Radon transform, we allow a general weight depending on the distance of the integration point from the vertex. As first main result, we show uniqueness of inversion for that transform. To stably invert the weighted conical Radon transform, we use general convex variational regularization. We present numerical minimization schemes based on the Chambolle-Pock primal dual algorithm. Within this framework, we compare various regularization terms, including non-negativity constraints, H I -regularization and total variation regularization. Compared to standard quadratic Tikhonov regularization, TV-regularization is demonstrated to significantly increase the reconstruction quality from conical Radon data.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Variational regularization of the weighted conical Radon transform

Haltmeier

Schiefeneder

2018

Inverse Problems

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“…High energy radiopharmaceuticals, in some cases, cannot be substituted for low energy radiotracers, not only because they have unique chemical properties and medical specificity, but also due to their longer physical halflives which makes it possible to obtain images of the patient several days after the compounds are administered. Thus, clearance of non-specific uptake is permitted, which results in high specific localization of the agent; and results in better contrast of tumor to background tissues [5] [6].…”

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confidence: 99%

Performance Evaluation of Compton Based Camera for High Energy Gamma Ray Imaging

Han¹,

Clinthorne²

IEEE Nuclear Science Symposium Conference Record, 2005

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The imaging performance of Compton scattering based gamma-ray camera and Anger camera with High Energy General Purpose (HEGP) Collimator, in terms of spatial resolution, variance of reconstructed image and detection sensitivity for high-energy 364.4Kev photons of I-131, are evaluated by modified Uniform Cramer-Rao Bound and Monte Carlo Simulation. Compared to the conventional collimated gamma-ray camera, the electronically collimated camera has the potential for superior imaging quality due to its improved counting efficiency and spatial resolution for I-131 radiotracers. The simulation platform for the Compton imaging system and conventional SPECT are realized on GEANT4 and GATE (Geant4 Application for Topographic Emission), respectively. In the Compton imaging system, the first scattering detectorelectronic collimator has 32×16 Silicon pads with dimension of 1.4mm × 1.4mm × 1.0mm (width × length × thickness); the second absorption detector is modeled as a NaI scintillation detector with thickness of 9.5mm. A conventional sodium iodide SPECT camera is also simulated using GATE with crystal thickness of 9.5mm and 381mm×508mm field of view. The preliminary study demonstrates that the modeled Compton camera is more efficient than the conventional collimated camera for 364.4KeV photons with higher sensitivity about 30x. Meanwhile, for the same desired PSF, the Compton Camera has lower variance than the conventional Anger camera with HEGP collimator.

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Compton camera coincidences in the silicon drift detector

Conka-Nurdan

Nurdan

Walenta

et al.

IEEE Symposium Conference Record Nuclear Science 2004.

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A Compton camera system consisting of a silicon drift detector (SDD) and an Anger camera has been constructed to study coincidence events and the possibility of tracking a recoil electron. An event is considered as a coincidence when a photon emitted from a radioactive source is first Compton scattered in the SDD where the recoil electron deposits its energy and the scattered photon undergoes a photoelectric absorption in the NaI(Tl) crystal of the Anger camera. SDD is composed of a monolithic array of 19 cells each having an on-chip transistor which provides the first stage amplification. 137 Cs source has been finely collimated in order to study events occuring at different locations within a single cell. Electron tracks depositing energy in multiple cells have also been studied by considering time coincidences between SDD cells and the Anger camera. The equipment is designed such that the measurements can be done in all detector orientations and kinematical conditions. The angular and energy distribution of coincidence events have been studied with high statistics. Energy resolution and angle measurements performed with this detector system will be presented in this paper.

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Compton Cameras for Nuclear Medical Imaging

Cited by 11 publications

References 0 publications

Variational regularization of the weighted conical Radon transform

Variational regularization of the weighted conical Radon transform

Performance Evaluation of Compton Based Camera for High Energy Gamma Ray Imaging

Compton camera coincidences in the silicon drift detector

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