Parametric positioning of a continuous crystal PET detector with depth of interaction decoding

Ling, Tao; Burnett, T. H.; Lewellen, T.K.; Miyaoka, Robert S.

doi:10.1088/0031-9155/53/7/003

Cited by 53 publications

(54 citation statements)

References 17 publications

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“…If A i can be considered normally distributed the more flexible weighted least squares (WLS) method can be used instead of ML [18]. In this case the parameter estimates are found by minimising the weighted sum of squared residuals…”

Section: Weighted Least Squaresmentioning

confidence: 99%

Position reconstruction in a dual phase xenon scintillation detector

Solovov¹,

Belov²,

Akimov³

et al. 2011

2011 IEEE Nuclear Science Symposium Conference Record

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Abstract-We studied the application of statistical reconstruction algorithms, namely maximum likelihood and least squares methods, to the problem of event reconstruction in a dual phase liquid xenon detector. An iterative method was developed for in-situ reconstruction of the PMT light response functions from calibration data taken with an uncollimated γ-ray source. Using the techniques described, the performance of the ZEPLIN-III dark matter detector was studied for 122 keV γ-rays. For the inner part of the detector (R<100 mm), spatial resolutions of 13 mm and 1.6 mm FWHM were measured in the horizontal plane for primary and secondary scintillation, respectively. An energy resolution of 8.1% FWHM was achieved at that energy. The possibility of using this technique for improving performance and reducing cost of scintillation cameras for medical applications is currently under study.

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Section: Weighted Least Squaresmentioning

confidence: 99%

Position reconstruction in a dual phase xenon scintillation detector

Solovov¹,

Belov²,

Akimov³

et al. 2011

2011 IEEE Nuclear Science Symposium Conference Record

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“…The first class comprehends the positioning algorithms based on modelling of the relation between the 3D position of the light source inside the crystal and the light distribution measured by the photosensor [17], [19]. The main advantage of these methods is that they need little or no calibration data, since they are based on geometrical and physical considerations.…”

Section: Introductionmentioning

confidence: 99%

“…The main advantage of these methods is that they need little or no calibration data, since they are based on geometrical and physical considerations. However, these models usually have difficulties in positioning events close to the edges of the crystals, due to the truncation of the measured light distribution [17] and might not be robust in case of 0018-9499 © 2015 IEEE. Personal use is permitted, but republication/redistribution requires IEEE permission.…”

Section: Introductionmentioning

confidence: 99%

Experimental Validation of an Efficient Fan-Beam Calibration Procedure for <formula formulatype="inline"><tex Notation="TeX">$k$</tex></formula>-Nearest Neighbor Position Estimation in Monolithic Scintillator Detectors

Borghi

Tabacchini

Seifert

et al. 2015

IEEE Trans. Nucl. Sci.

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Monolithic scintillator detectors can achieve excellent spatial resolution and coincidence resolving time. However, their practical use for positron emission tomography (PET) and other applications in the medical imaging field is still limited due to drawbacks of the different methods used to estimate the position of interaction. Common statistical methods for example require the collection of an extensive dataset of reference events with a narrow pencil beam aimed at a fine grid of reference positions. Such procedures are time consuming and not straightforwardly implemented in systems composed of many detectors. Here, we experimentally demonstrate for the first time a new calibration procedure for -nearest neighbor ( -NN) position estimation that utilizes reference data acquired with a fan beam. The procedure is tested on two detectors consisting of mm mm mm and mm mm mm monolithic, Ca-codoped LSO:Ce crystals and digital photon counter (DPC) arrays. For both detectors, the spatial resolution and the bias obtained with the new method are found to be practically the same as those obtained with the previously used method based on pencil-beam irradiation, while the calibration time is reduced by a factor of . Specifically, a FWHM of mm and a FWTM of mm were obtained using the fan-beam method with the 10 mm crystal, whereas a FWHM of mm and a FWTM of mm were achieved with the 20 mm crystal. Using a fan beam made with a MBq point-source and a tungsten slit collimator with 0.5 mm aperture, the total measurement time needed to acquire the reference dataset was hours for the thinner crystal and hours for the thicker one.Index Terms-Calibration, fan beam, monolithic scintillator detector, nearest neighbor method, PET, positron emission tomography.

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“…These methods require an accurate model of the light spread function and they require a well-collimated high count-rate gamma-ray source for sufficient penetration through the width or slant-thickness of the detector. Using a modeled detector response functions have also been examined [4,5]. However, a modeled response function may not account for detector irregularities and can result in estimate bias.…”

Section: Introductionmentioning

confidence: 99%

A comparison of Maximum List-Mode-Likelihood Estimation and Maximum-Likelihood Clustering algorithms for depth calibration in continuous-crystal PET detectors

Lewellen

Miyaoka

2012

2012 IEEE Nuclear Science Symposium and Medical Imaging Conference Record (NSS/MIC)

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Parallax error in close-proximity applications of thick gamma-ray detectors, such as preclinical or organ-specific Positron Emission Tomography, motivates the need to accurately resolve interaction depth. In our lab, we routinely use a collimated gamma-ray source and apply an iterative maximum likelihood clustering (MLC) algorithm to calibrate detector response statistics as a function of 3D interaction position. These detector response functions calibrate a signal-probability model that we use to determine the interaction position of events by maximum likelihood estimation. In this work, we compare the accuracy of this clustering algorithm to a more computationally intensive method (MLMLE) that maximizes the list-mode likelihood of a parametric model of the detector response function. Accuracy of the calibrated mean and variance of detector response versus depth are experimentally determinedfor a slat-shaped detector using a collimated gamma-rays normally incident to the side of the slat. We also verify our experimental findings by Monte-Carlo simulation, where ground truth is known. Our results suggest that MLMLE is more accurate than MLC for estimating the variance of detector response, but these algorithms fair similarly for accurately estimating the mean detector response. However, for the reduced dimensional case considered, the MLC algorithm required nearly 1 minute to execute, while the MLMLE algorithm took just over 10 hours to complete.

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Parametric positioning of a continuous crystal PET detector with depth of interaction decoding

Cited by 53 publications

References 17 publications

Position reconstruction in a dual phase xenon scintillation detector

Position reconstruction in a dual phase xenon scintillation detector

Experimental Validation of an Efficient Fan-Beam Calibration Procedure for <formula formulatype="inline"><tex Notation="TeX">$k$</tex></formula>-Nearest Neighbor Position Estimation in Monolithic Scintillator Detectors

A comparison of Maximum List-Mode-Likelihood Estimation and Maximum-Likelihood Clustering algorithms for depth calibration in continuous-crystal PET detectors

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