Implementation of an accelerated iterative algorithm for cone-beam SPECT.
In this paper we describe the implementation of an accelerated iterative reconstruction algorithm (AIRA) for cone-beam (CB) projections using a single circular orbit in single-photon-emission computed tomography (SPECT). This algorithm is a modified maximum-likelihood-expectation-maximization (ML-EM) algorithm and several approaches have been used to accelerate the reconstruction process. These approaches include: (i) the use of ordered subsets; (ii) the use of active areas and volumes; and (iii) the storing in memory of the transition vector for a given ray (during the forward projection step). This algorithm, which compensates for collimator geometric sensitivity variation as a function of position and makes uniform attenuation corrections has been evaluated using experimentally acquired phantom data. The results demonstrate a two-orders-of-magnitude decrease of the computational time of this algorithm over the conventional ML-EM algorithm with similar convergence properties.
Li
J
J
Department of Radiology, PO Box 3949, Duke University Medical Center, Durham, NC 27710, USA.
Jaszczak
R J
RJ
Greer
K L
KL
Coleman
R E
RE
D000465:Algorithms; D016477:Artifacts; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D016013:Likelihood Functions; D015233:Models, Statistical; D019047:Phantoms, Imaging; D017785:Photons; D012680:Sensitivity and Specificity; D012984:Software; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*