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3D PET using a conventional multislice tomograph without septa.

S R Cherry·M Dahlbom·E J Hoffman
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Abstract

A conventional multislice positron emission tomography scanner was modified to operate without interplane septa to evaluate its performance in collecting and reconstructing data in a three-dimensional (3D) format, thereby significantly increasing system sensitivity. A 3D filtered backprojection algorithm was implemented and tested, using both computer simulations and phantom measurements. No artifacts were apparent in the test images, although the algorithm was shown to lead to a 11% degradation in transaxial resolution in the outer planes. Following septa removal, sensitivity was found to increase by a factor of 7 with an increase in scatter fraction from 16 to 41%. Axial resolution degraded from 6.9 to 7.7 mm full width at half maximum at the center of the field of view. The maximum count rate without septa was 2.4 x 10(5) cps, at a concentration of 0.4 microCi/ml, compared with 1.3 x 10(5) cps at 1.5 microCi/ml with septa. Brain studies were performed with volunteers using 18F-fluorodeoxyglucose, 18F-fluorodopa, and H2 15O to compare noise-equivalent count rates and qualitatively assess image quality over a wide range of imaging conditions.

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AlgorithmsBrainHumansImage Processing, Computer-AssistedTomography, Emission-ComputedJournal ArticleResearch Support, U.S. Gov't, Non-P.H.S.Research Support, U.S. Gov't, P.H.S.

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S R Cherry, M Dahlbom, E J Hoffman. 3D PET using a conventional multislice tomograph without septa.. https://doi.org/10.1097/00004728-199107000-00023

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