Estimation of half fan-beam collimator parameters for brain SPECT with an L-shaped dual camera SPECT system

D. P. Lewis, Benjamin Tsui

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

Abstract

Accurate determination of collimator and imaging parameters for asymmetric fan-beam collimators is critical for accurate reconstructions. Previously the parameters were estimated by fitting data from a line source to an analytical model using the Marquardt algorithm. We have found with this method that (1) the parameters often cannot be determined uniquely, (2) local minima are problematic, and (3) the global minimum resides in a long narrow valley that contributes to the instability of the problem. In addition, inaccurate parameter estimates from multiple cameras can lead to misregistration problems and loss of resolution. We have developed a parameter estimation method to determine the unique set of parameters using multiple line sources and/or radii-of-rotation with the Powell algorithm. This new method was tested using both simulated data and data experimentally collected from a GE Optima L-shaped dual-camera SPECT system fitted with two half fan-beam collimators designed for high resolution brain SPECT. The results indicate that our new method provides stable and accurate estimates of the parameters, resulting in fewer image artifacts and higher resolution in the final reconstructed image than the previous method. The accuracy of our new method is demonstrated by reconstructions of a set of multiple line sources and a 3D Hoffman brain phantom.

Original languageEnglish (US)
Title of host publicationIEEE Nuclear Science Symposium & Medical Imaging Conference
EditorsO. Nalcioglu
PublisherIEEE
Pages1052-1056
Number of pages5
Volume2
Publication statusPublished - 1997
Externally publishedYes
EventProceedings of the 1997 IEEE Nuclear Science Symposium - Albuquerque, NM, USA
Duration: Nov 9 1997Nov 15 1997

Other

OtherProceedings of the 1997 IEEE Nuclear Science Symposium
CityAlbuquerque, NM, USA
Period11/9/9711/15/97

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ASJC Scopus subject areas

  • Engineering(all)

Cite this

Lewis, D. P., & Tsui, B. (1997). Estimation of half fan-beam collimator parameters for brain SPECT with an L-shaped dual camera SPECT system. In O. Nalcioglu (Ed.), IEEE Nuclear Science Symposium & Medical Imaging Conference (Vol. 2, pp. 1052-1056). IEEE.