Title :
Reconstruction of attenuation map using discrete consistency conditions
Author :
Bronnikov, Andrei V.
Author_Institution :
KEMA, Arnhem, Netherlands
fDate :
5/1/2000 12:00:00 AM
Abstract :
Methods of quantitative emission computed tomography require compensation for linear photon attenuation. A current trend in single-photon emission computed tomography (SPECT) and positron emission tomography (PET) is to employ transmission scanning to reconstruct the attenuation map. Such an approach, however, considerably complicates both the scanner design and the data acquisition protocol. A dramatic simplification could be made if the attenuation map could be obtained directly from the emission projections, without the use of a transmission scan. This can be done by applying the consistency conditions that enable one to identify the operator of the problem and, thus, to reconstruct the attenuation map. Here, the authors propose a new approach based on the discrete consistency conditions. One of the main advantages of the suggested method over previously used continuous conditions is that it can easily be applied in various scanning configurations, including fully three-dimensional (3-D) data acquisition protocols. Also, it provides a stable numerical implementation, allowing one to avoid the crosstalk between the attenuation map and the source function. A computationally efficient algorithm is implemented by using the QR and Cholesky decompositions. Application of the algorithm to computer-generated and experimentally measured SPECT data is considered.
Keywords :
gamma-ray absorption; image reconstruction; medical image processing; positron emission tomography; single photon emission computed tomography; Cholesky decomposition; PET; SPECT; attenuation map reconstruction; discrete consistency conditions; medical diagnostic imaging; nuclear medicine; scanning configuration; source function; Application software; Attenuation; Computed tomography; Crosstalk; Data acquisition; Equations; Image reconstruction; Positron emission tomography; Protocols; Single photon emission computed tomography; Algorithms; Computer Simulation; Heart; Humans; Image Processing, Computer-Assisted; Lung; Models, Theoretical; Phantoms, Imaging; Thorax; Time Factors; Tomography, Emission-Computed; Tomography, Emission-Computed, Single-Photon;
Journal_Title :
Medical Imaging, IEEE Transactions on