Journal ArticleDOI
Parameter Estimation for Dynamic Studies in Emission-Tomography Systems Having List-Mode Data
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TLDR
It is shown how the EM iterative algorithm of statistics can be used to estimate compartmental parameters just as it is also used to reconstruct images of activity distributions to estimate maximum-likelihood parameter estimation for dynamic tracer-studies.Abstract:
Maximum-likelihood parameter estimation for dynamic tracer-studies is investigated for emission-tomography systems having time-of-flight measurements in the form of list-mode data. It is shown how the EM iterative algorithm of statistics can be used to estimate compartmental parameters just as it is also used to reconstruct images of activity distributions. Retrospective processing of list-mode data for dynamic studies requires that the influence of each measurement point to the region of interest in the reconstructed images be identified; a procedure for accomplishing this is given.read more
Citations
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Proceedings ArticleDOI
Design of a motion-compensation OSEM list-mode algorithm for resolution-recovery reconstruction for the HRRT
TL;DR: MOLAR, a motion-compensation OSEM list-mode algorithm for resolution-recovery reconstruction on a computer cluster with the following features is designed: direct use of list mode data with dynamic motion information (Polaris), and exact reprojection of each line-of- response (LOR).
Journal ArticleDOI
List-mode likelihood
TL;DR: This paper presents expressions for list-mode likelihood with an arbitrary number of attributes per photon and for both preset counts and preset time for photon-counting imaging systems.
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Spatiotemporal reconstruction of list-mode PET data
TL;DR: A method for computing a continuous time estimate of tracer density using list-mode positron emission tomography data using an inhomogeneous Poisson process whose rate function can be represented using a cubic B-spline basis is described.
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Four-dimensional (4D) image reconstruction strategies in dynamic PET: beyond conventional independent frame reconstruction.
TL;DR: Novel techniques in the emerging field of spatiotemporal four-dimensional (4D) positron emission tomography (PET) image reconstruction are reviewed, including techniques that utilize iterative temporal smoothing, principal components transformation of the dynamic data, wavelet-based techniques, as well as direct kinetic parameter estimation methods.
Journal ArticleDOI
Direct least-squares estimation of spatiotemporal distributions from dynamic SPECT projections using a spatial segmentation and temporal B-splines
TL;DR: A preliminary study of spatial segmentation errors showed that spatial model mismatch adversely affected quantitative accuracy, but also resulted in structured errors that were easily detected in the authors' simulations, suggesting iterative refinement of the spatial model to reduce structured errors as an area of future research.
References
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Journal ArticleDOI
Maximum likelihood from incomplete data via the EM algorithm
Journal ArticleDOI
Maximum Likelihood Reconstruction for Emission Tomography
L. A. Shepp,Y. Vardi +1 more
TL;DR: In this paper, the authors proposed a more accurate general mathematical model for ET where an unknown emission density generates, and is to be reconstructed from, the number of counts n*(d) in each of D detector units d. Within the model, they gave an algorithm for determining an estimate? of? which maximizes the probability p(n*|?) of observing the actual detector count data n* over all possible densities?.
Journal Article
EM reconstruction algorithms for emission and transmission tomography.
Kenneth Lange,Richard E. Carson +1 more
TL;DR: The general principles behind all EM algorithms are discussed and in detail the specific algorithms for emission and transmission tomography are derived and the specification of necessary physical features such as source and detector geometries are discussed.
Journal ArticleDOI
A Matheematical Model for Positron-Emission Tomography Systems Having Time-of-Flight Measurements
TL;DR: In this paper, a mathematical model for differential time-of-flight measurements in tomography systems that employ coincidence detection of the annihilation photons created with positron emitting radionuclides is developed.
Journal ArticleDOI
Image Reconstruction from List-Mode Data in an Emission Tomography System Having Time-of-Flight Measurements
TL;DR: It is argued in this paper that the additional information present in the three-dimensional data is useful for improving reconstructions of images.