Journal ArticleDOI
Accelerated image reconstruction using ordered subsets of projection data
H.M. Hudson,R.S. Larkin +1 more
TLDR
Ordered subsets EM (OS-EM) provides a restoration imposing a natural positivity condition and with close links to the EM algorithm, applicable in both single photon (SPECT) and positron emission tomography (PET).Abstract:
The authors define ordered subset processing for standard algorithms (such as expectation maximization, EM) for image restoration from projections. Ordered subsets methods group projection data into an ordered sequence of subsets (or blocks). An iteration of ordered subsets EM is defined as a single pass through all the subsets, in each subset using the current estimate to initialize application of EM with that data subset. This approach is similar in concept to block-Kaczmarz methods introduced by Eggermont et al. (1981) for iterative reconstruction. Simultaneous iterative reconstruction (SIRT) and multiplicative algebraic reconstruction (MART) techniques are well known special cases. Ordered subsets EM (OS-EM) provides a restoration imposing a natural positivity condition and with close links to the EM algorithm. OS-EM is applicable in both single photon (SPECT) and positron emission tomography (PET). In simulation studies in SPECT, the OS-EM algorithm provides an order-of-magnitude acceleration over EM, with restoration quality maintained. >read more
Citations
More filters
Journal Article
A combined PET/CT scanner for clinical oncology.
Thomas Beyer,David W. Townsend,Tony Brun,Paul E. Kinahan,Martin Charron,Raymond Roddy,Jeff Jerin,J. Young,L.G. Byars,Ronald Nutt +9 more
TL;DR: A combined PET and CT scanner is a practical and effective approach to acquiring co-registered anatomical and functional images in a single scanning session.
Journal ArticleDOI
A unified treatment of some iterative algorithms in signal processing and image reconstruction
TL;DR: The Krasnoselskii?Mann (KM) approach to finding fixed points of nonlinear continuous operators on a Hilbert space was introduced in this article, where a wide variety of iterative procedures used in signal processing and image reconstruction and elsewhere are special cases of the KM iterative procedure.
Journal ArticleDOI
Clinical Applications of PET in Oncology
TL;DR: The physics and instrumentation aspects of PET, an analogue of glucose, are described and are being used in diagnosis and follow-up of several malignancies, and the list of articles supporting its use continues to grow.
Journal ArticleDOI
The EM Algorithm—an Old Folk‐song Sung to a Fast New Tune
Xiao-Li Meng,David A. van Dyk +1 more
TL;DR: A general alternating expectation–conditional maximization algorithm AECM is formulated that couples flexible data augmentation schemes with model reduction schemes to achieve efficient computations and shows the potential for a dramatic reduction in computational time with little increase in human effort.
Journal ArticleDOI
Exact and approximate rebinning algorithms for 3-D PET data
TL;DR: This paper presents two new rebinning algorithms for the reconstruction of three-dimensional (3-D) positron emission tomography (PET) data that are approximate but allows an efficient implementation based on taking 2-D Fourier transforms of the data.
References
More filters
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 ArticleDOI
Algebraic Reconstruction Techniques (ART) for three-dimensional electron microscopy and X-ray photography
TL;DR: The method works for totally asymmetric objects, and requires little computer time or storage, and is also applicable to X-ray photography, and may greatly reduce the exposure compared to current methods of body-section radiography.
Journal ArticleDOI
Iterative methods for the three-dimensional reconstruction of an object from projections
TL;DR: It is shown that in general ART produces erroneous reconstructions, and an alternative iterative method is proposed which will give correct reconstructions under certain conditions.
Journal ArticleDOI
Generalized Iterative Scaling for Log-Linear Models
J. N. Darroch,D. Ratcliff +1 more
TL;DR: In this article, the authors generalized the iterative scaling method to allow real numbers and showed that it is possible to estimate a large class of probability distributions in product form subject to (1) and (2) or from maximizing entropy or maximizing likelihood.
Journal ArticleDOI
Bayesian reconstructions from emission tomography data using a modified EM algorithm
TL;DR: This method builds on the expectation-maximization approach to maximum likelihood reconstruction from emission tomography data, but aims instead at maximum posterior probability estimation, which takes account of prior belief about smoothness in the isotope concentration.
Related Papers (5)
EM reconstruction algorithms for emission and transmission tomography.
Kenneth Lange,Richard E. Carson +1 more