DocumentCode :
1029398
Title :
Hybrid parallel-slant hole collimators for SPECT imaging
Author :
Bai, Chuanyong ; Shao, Ling ; Ye, Jinghan ; Durbin, Mary ; Petrillo, Mike
Author_Institution :
Digirad Corp., Poway, CA, USA
Volume :
51
Issue :
3
fYear :
2004
fDate :
6/1/2004 12:00:00 AM
Firstpage :
619
Lastpage :
624
Abstract :
We propose a new collimator geometry, the hybrid parallel-slant (HPS) hole geometry, to improve sensitivity for SPECT imaging with large field of view (LFOV) gamma cameras. A HPS collimator has one segment with parallel holes and one or more segments with slant holes. The collimator can be mounted on a conventional SPECT LFOV system that uses parallel-beam collimators, and no additional detector or collimator motion is required for data acquisition. The parallel segment of the collimator allows for the acquisition of a complete data set of the organs-of-interest and the slant segments provide additional data. In this work, simulation studies of an MCAT phantom were performed with a HPS collimator with one slant segment. The slant direction points from patient head to patient feet with a slant angle of 30°. We simulated 64 projection views over 180° with the modeling of nonuniform attenuation effect, and then reconstructed images using an MLEM algorithm that incorporated the hybrid geometry. It was shown that sensitivity to the cardiac region of the phantom was increased by approximately 50% when using the HPS collimator compared with a parallel-hole collimator. No visible artifacts were observed in the myocardium and the signal-to-noise ratio (SNR) of the myocardium walls was improved. Compared with collimators with other geometries, using a HPS collimator has the following advantages: (a) significant sensitivity increase; (b) a complete data set obtained from the parallel segment that allows for artifact-free image reconstruction; and (c) no additional collimator or detector motion. This work demonstrates the potential value of hybrid geometry in collimator design for LFOV SPECT imaging.
Keywords :
biomedical imaging; collimators; data acquisition; image reconstruction; phantoms; single photon emission computed tomography; MCAT phantom; MLEM algorithm; SPECT imaging; artifact-free image reconstruction; cardiac region; collimator geometry; hybrid parallel-slant hole collimators; large field of view gamma cameras; myocardium walls; nonuniform attenuation effect; patient feet; patient head; reconstructed images; signal-to-noise ratio; Collimators; Detectors; Geometry; Image reconstruction; Image segmentation; Imaging phantoms; Motion detection; Myocardium; Optical imaging; Solid modeling; Collimator geometry; FOV; HPS; SPECT; field of view; hole collimator; hybrid parallel-slant;
fLanguage :
English
Journal_Title :
Nuclear Science, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9499
Type :
jour
DOI :
10.1109/TNS.2004.829590
Filename :
1310573
Link To Document :
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