Least-square pinhole SPECT calibration using a forward projector modeling misalignment

Christian Wietholt, Chin Tu Chen, Geng Fu, Ling Jian Meng

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Recent improvements in detector technology allow pinhole SPECT to approach spatial resolutions as low as 50 μm. Such high resolutions require a high accuracy of the imaging gantry for preclinical SPECT systems, and is not easily achieved in a laboratory setting. Analytical calibration methods are deemed to fail due to practical implications such as size and activity concentrations of the required point sources. Thus, we have developed a numerical calibration method based on leastsquare optimization that incorporates the modeling attributes of a forward projector frequently used in iterative reconstruction. The forward projector is currently capable of modeling detector misalignment such as detector rotation and pinhole translation, and will incorporate the pinhole point spread function as well as the size and shape of the point source. Currently, our calibration phantom consists of a single point source, positioned off-center in the object space. The optimization method involves a sequentially fitting of each individual parameter to the data, followed by fitting multiple parameters simultaneous in consecutive steps including all five parameters for the final fitting. The results of the optimization show an error of expected magnitude considering the relatively coarse sampling grid of our simulations. The relatively slow convergence of the y- and z-tilt require simulation of additional point sources. Further improvements of computational and memory efficiency need to be made, which enable the method to fit high resolution data as well as incorporation of the pinhole point spread function and the shape and size of the point sources.

Original languageEnglish (US)
Title of host publication2007 IEEE Nuclear Science Symposium and Medical Imaging Conference, NSS-MIC
Pages4543-4545
Number of pages3
DOIs
StatePublished - Dec 1 2007
Externally publishedYes
Event2007 IEEE Nuclear Science Symposium and Medical Imaging Conference, NSS-MIC - Honolulu, HI, United States
Duration: Oct 27 2007Nov 3 2007

Publication series

NameIEEE Nuclear Science Symposium Conference Record
Volume6
ISSN (Print)1095-7863

Other

Other2007 IEEE Nuclear Science Symposium and Medical Imaging Conference, NSS-MIC
CountryUnited States
CityHonolulu, HI
Period10/27/0711/3/07

Fingerprint

Optical transfer function
Calibration
Detectors
Sampling
Imaging techniques
Data storage equipment

ASJC Scopus subject areas

  • Radiation
  • Nuclear and High Energy Physics
  • Radiology Nuclear Medicine and imaging

Cite this

Wietholt, C., Chen, C. T., Fu, G., & Meng, L. J. (2007). Least-square pinhole SPECT calibration using a forward projector modeling misalignment. In 2007 IEEE Nuclear Science Symposium and Medical Imaging Conference, NSS-MIC (pp. 4543-4545). [4437121] (IEEE Nuclear Science Symposium Conference Record; Vol. 6). https://doi.org/10.1109/NSSMIC.2007.4437121

Least-square pinhole SPECT calibration using a forward projector modeling misalignment. / Wietholt, Christian; Chen, Chin Tu; Fu, Geng; Meng, Ling Jian.

2007 IEEE Nuclear Science Symposium and Medical Imaging Conference, NSS-MIC. 2007. p. 4543-4545 4437121 (IEEE Nuclear Science Symposium Conference Record; Vol. 6).

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Wietholt, C, Chen, CT, Fu, G & Meng, LJ 2007, Least-square pinhole SPECT calibration using a forward projector modeling misalignment. in 2007 IEEE Nuclear Science Symposium and Medical Imaging Conference, NSS-MIC., 4437121, IEEE Nuclear Science Symposium Conference Record, vol. 6, pp. 4543-4545, 2007 IEEE Nuclear Science Symposium and Medical Imaging Conference, NSS-MIC, Honolulu, HI, United States, 10/27/07. https://doi.org/10.1109/NSSMIC.2007.4437121
Wietholt C, Chen CT, Fu G, Meng LJ. Least-square pinhole SPECT calibration using a forward projector modeling misalignment. In 2007 IEEE Nuclear Science Symposium and Medical Imaging Conference, NSS-MIC. 2007. p. 4543-4545. 4437121. (IEEE Nuclear Science Symposium Conference Record). https://doi.org/10.1109/NSSMIC.2007.4437121
Wietholt, Christian ; Chen, Chin Tu ; Fu, Geng ; Meng, Ling Jian. / Least-square pinhole SPECT calibration using a forward projector modeling misalignment. 2007 IEEE Nuclear Science Symposium and Medical Imaging Conference, NSS-MIC. 2007. pp. 4543-4545 (IEEE Nuclear Science Symposium Conference Record).
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