1. The design and performance of a simultaneous transmission and emission tomography system
- Author
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Gullberg, Grant T., Morgan, Hugh T., Zeng, Gengsheng L., Christian, Paul E., Di Bella, Edward V.R., Tung, Chi-Hua, Maniawski, Piotr J., Hsieh, Yu-Lung, and Datz, Frederick L.
- Subjects
SPECT imaging -- Equipment and supplies ,Tomography -- Equipment and supplies ,Scanning devices -- Research ,Business ,Electronics ,Electronics and electrical industries - Abstract
A commercial three-detector single-photon emission computed tomography (SPECT) system that enables simultaneous acquisition of transmission and emission data without increasing patient scanning time has been designed and manufactured. This system produces a reconstructed attenuation coefficient distribution that can be used to correct for photon attenuation in the emission reconstruction. The three detectors with fan-beam collimators are mounted to the gantry in a triangular arrangement. A transmission line source assembly was mounted at the focal line of one of the detectors and controlled to move in synchrony with the opposing fan-beam collimator. Data from transmission and emission sources at different energies were acquired in one detector, while the other two simultaneously acquired emission data. A transmission source of 153Gd was used with 99mTc-labeled radiopharmaceuticals, and 57Co was used with 201Tl. Algorithms were developed to subtract crosstalk between transmission and emission energy windows in all three detectors. A transmission maximum-likelihood iterative algorithm was used to reconstruct the attenuation distribution, which was used in combination with an iterative maximum-likelihood expectation-maximization algorithm to compensate for the attenuation of the projection of the emission distribution. The results in phantom studies displayed greater uniformity of activity with attenuation-corrected reconstruction. This was demonstrated visually and quantitatively by using anterior-to-inferior ratios close to one and low spatial %rms error as a measure of improved uniformity. Index Terms - Anger gamma camera, attenuation correction, brain SPECT, cardiac SPECT, clinical imaging hardware, clinical imaging software, emission computed tomography, fan-beam tomography, iterative reconstruction, simultaneous transmission and emission imaging, single-photon emission computed tomography, SPECT, transmission computed tomography.
- Published
- 1998