Quantitative multi-pinhole small-animal SPECT: uniform versus non-uniform Chang attenuation correction

C. Wu*, J. R. de Jong, H. A. Gratama van Andel, F. van der Have, B. Vastenhouw, P. Laverman, O. C. Boerman, R. A. J. O. Dierckx, F. J. Beekman

*Corresponding author for this work

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    22 Citations (Scopus)

    Abstract

    Attenuation of photon flux on trajectories between the source and pinhole apertures affects the quantitative accuracy of reconstructed single-photon emission computed tomography (SPECT) images. We propose a Chang-based non-uniform attenuation correction (NUA-CT) for small-animal SPECT/CT with focusing pinhole collimation, and compare the quantitative accuracy with uniform Chang correction based on (i) body outlines extracted from x-ray CT (UA-CT) and (ii) on hand drawn body contours on the images obtained with three integrated optical cameras (UA-BC). Measurements in phantoms and rats containing known activities of isotopes were conducted for evaluation. In (125)I, (201)Tl, (99m)Tc and (111)In phantom experiments, average relative errors comparing to the gold standards measured in a dose calibrator were reduced to 5.5%, 6.8%, 4.9% and 2.8%, respectively, with NUA-CT. In animal studies, these errors were 2.1%, 3.3%, 2.0% and 2.0%, respectively. Differences in accuracy on average between results of NUA-CT, UA-CT and UA-BC were less than 2.3% in phantom studies and 3.1% in animal studies except for (125)I (3.6% and 5.1%, respectively). All methods tested provide reasonable attenuation correction and result in high quantitative accuracy. NUA-CT shows superior accuracy except for (125)I, where other factors may have more impact on the quantitative accuracy than the selected attenuation correction.

    Original languageEnglish
    Pages (from-to)N183-N193
    Number of pages11
    JournalPhysics in Medicine and Biology
    Volume56
    Issue number18
    DOIs
    Publication statusPublished - 21-Sep-2011

    Keywords

    • HIGH-RESOLUTION
    • SCATTER CORRECTION
    • RECONSTRUCTION
    • CT
    • PENETRATION
    • INFORMATION
    • SENSITIVITY
    • TOMOGRAPHY
    • IMAGES

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