Large surface gamma cameras for medical imaging: characterization of the bismuth germanate blocks

Fontana, Mattia; Dauvergne, D.; Negra, R. Della; Létang, Jean Michel; Mounier, F.; Testa, É.; Zanetti, L.; Zoccarato, Y.

doi:10.1088/1748-0221/13/08/p08018

Cited by 4 publications

(2 citation statements)

References 15 publications

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“…In contrast, PET detects the coincidence of two 511 keV gamma rays emitted in opposite directions when a positron annihilates with an electron [4]. In contrast, Compton cameras use electronic collimators and do not require mechanical collimators for multinuclear imaging [5]. Although there has been less attention on electronic collimators in recent years, several studies have succeeded with Compton cameras.…”

Section: Introductionmentioning

confidence: 99%

Design and Simulation of a Semiconductor Detector-Based Compton Imaging System with Efficiency Analysis

Niknami,

Hosseini,

Ebrahimi Loushab

2023

Preprint

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Compton cameras detect scattered gamma rays and estimate the distribution of gamma-ray sources. Nonetheless, crafting a camera tailored to a specific application presents formidable challenges, often necessitating the implementation of diverse image reconstruction techniques. Delving into the factors influencing these cameras can pave the way for design optimization and performance enhancement. This study introduces an inventive detector design for Compton imaging systems, building upon the achievements of prior designs. The proposed system contains eight scatterer detectors and a semiconductor absorber detector, spaced at 1 mm and 30 mm intervals, respectively. The source-to-first-scatterer-detector distance is 5 mm, with scatterer and absorber detector plates measuring 70× 70× 2.125 mm3 and 70× 70× 10 mm3, respectively. Geant4 simulation toolkit models the Compton imaging system, and an analytical method reconstructs Compton camera images. Unlike more straightforward techniques, the analytical method directly reconstructs Compton camera images by solving the equation relating to the reflected image data. This approach is implemented in the C++ programming language. The study's findings reveal that the analytical method discerns optimal conditions and parameters that significantly influence efficiency, yielding a full width at half maximum (FWHM) of 3.7 mm with an angular uncertainty of approximately 2.7 degrees at an energy level of 0.662 MeV. Compared to another experimental design employing the analytical image reconstruction approach, the FWHM value decreased by 0.7 mm. This study presents an innovative detector design and an analytical reconstruction method for Compton imaging systems, showcasing improved efficiency and accuracy.

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Section: Introductionmentioning

confidence: 99%

Design and Simulation of a Semiconductor Detector-Based Compton Imaging System with Efficiency Analysis

Niknami,

Hosseini,

Ebrahimi Loushab

2023

Preprint

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“…One of our goals is to identify their weak points for the proposed applications in order to guide future developments. To this aim, we have simulated a CC based on the device being developed by the French collaboration CLaRyS [5]. This article partly focuses on the effects of data selection techniques and low-count measurements.…”

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confidence: 99%

Capability of MLEM and OE to Detect Range Shifts With a Compton Camera in Particle Therapy

Kohlhase

Wegener

Schaar

et al. 2020

IEEE Trans. Radiat. Plasma Med. Sci.

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To identify range deviations by using Compton cameras (CCs), tomographic image reconstruction of CC data is needed. Within this context, image reconstruction is usually performed using maximum likelihood expectation maximization (MLEM), and more recently, the origin ensemble (OE) algorithm. In this article, we investigate how MLEM and OE affect the precision and accuracy of estimated range deviations. In particular, we focus on the effects of data selection, statistical fluctuations, and artifact reduction. The use of external information of the beam path through a hodoscope was also explored. Additionally, two methods to calculate range deviations were tested. To this aim, realistic proton beams were simulated using GATE and data from single spots as well as from seven contiguous spots of an energy layer were reconstructed. MLEM and OE reacted differently to the poor data statistics. In general, both algorithms were able to detect range shifts for single spots, particularly when multiple coincidences were also considered. Selection of events corresponding to the most relevant energy peaks decreased the identification performance due to the lower statistics. When data from several contiguous spots were jointly reconstructed, the accuracy of the results degraded significantly, and nonzero shifts were assigned when no shifts had occurred. The limited size of the cameras and the subsequent restriction in the orientation and aperture of detected cones, as well as in the number of detected events are major challenges. Future efforts should be devoted to noise regularization and compensation for data truncation. Index Terms-Compton camera (CC), image reconstruction, particle therapy, prompt gamma imaging, range verification. I. INTRODUCTION I N RECENT years, Compton cameras (CCs) have attracted attention for range verification in particle therapy [1]-[6]. Within this context, the goal of the CC is to detect prompt gamma-rays (PG) that are emitted during de-excitation of Manuscript

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A µTCA Back-End Firmware for Data Acquisition and Slow Control of the CLaRyS Compton Camera

Caplan

Allegrini

Cachemiche

et al. 2019

2019 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC)

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With the aim to build a real-time controlled time-offlight Compton camera for an improved ion-range dose delivery control on hadrontherapy, as defined by the CLaRyS collaboration project, a programming data acquisition and slow control back-end electronics is necessary. This paper presents the FPGA based firmware architecture, embedded software and associated tools for the back-end electronics of CLaRyS, that is able to provide multiple 3 Gb/s optical links for data acquisition, trigger distribution and slow control over its detectors. Performance of the system based on simulations and analysis of the results acquired during the characterization of a beam hodoscope will be presented. Experiments were performed with the 65 MeV proton beam of the medical cyclotron at the Mediterranean Protontherapy Institute, in Nice.

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Large surface gamma cameras for medical imaging: characterization of the bismuth germanate blocks

Cited by 4 publications

References 15 publications

Design and Simulation of a Semiconductor Detector-Based Compton Imaging System with Efficiency Analysis

Design and Simulation of a Semiconductor Detector-Based Compton Imaging System with Efficiency Analysis

Capability of MLEM and OE to Detect Range Shifts With a Compton Camera in Particle Therapy

A µTCA Back-End Firmware for Data Acquisition and Slow Control of the CLaRyS Compton Camera

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