A1 Vertaisarvioitu alkuperäisartikkeli tieteellisessä lehdessä
A new reconstruction strategy for image improvement in pinhole SPECT
Tekijät: Zeniya T, Watabe H, Aoi T, Kim KM, Teramoto N, Hayashi T, Sohlberg A, Kudo H, Iida H
Kustantaja: SPRINGER
Julkaisuvuosi: 2004
Journal: European Journal of Nuclear Medicine and Molecular Imaging
Tietokannassa oleva lehden nimi: EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING
Lehden akronyymi: EUR J NUCL MED MOL I
Vuosikerta: 31
Numero: 8
Aloitussivu: 1166
Lopetussivu: 1172
Sivujen määrä: 7
ISSN: 1619-7070
DOI: https://doi.org/10.1007/s00259-004-1510-4
Tiivistelmä
Pinhole single-photon emission computed tomography (SPECT) is able to provide information on the biodistribution of several radioligands in small laboratory animals, but has limitations associated with nonuniform spatial resolution or axial blurring. We have hypothesised that this blurring is due to incompleteness of the projection data acquired by a single circular pinhole orbit, and have evaluated a new strategy for accurate image reconstruction with better spatial resolution uniformity. A pinhole SPECT system using two circular orbits and a dedicated three-dimensional ordered subsets expectation maximisation (3D-OSEM) reconstruction method were developed. In this system, not the camera but the object rotates, and the two orbits are at 90degrees and 45degrees relative to the object's axis. This system satisfies Tuy's condition, and is thus able to provide complete data for 3D pinhole SPECT reconstruction within the whole field of view (FOV). To evaluate this system, a series of experiments was carried out using a multiple-disk phantom filled with Tc-99m solution. The feasibility of the proposed method for small animal imaging was tested with a mouse bone study using Tc-99m-hydroxymethylene diphosphonate. Feldkamp's filtered back-projection (FBP) method and the 3D-OSEM method were applied to these data sets, and the visual and statistical properties were examined. Axial blurring, which was still visible at the edge of the FOV even after applying the conventional 3D-OSEM instead of FBP for single-orbit data, was not visible after application of 3D-OSEM using two-orbit data. 3D-OSEM using two-orbit data dramatically reduced the resolution non-uniformity and statistical noise, and also demonstrated considerably better image quality in the mouse scan. This system may be of use in quantitative assessment of biophysiological functions in small animals.
Pinhole single-photon emission computed tomography (SPECT) is able to provide information on the biodistribution of several radioligands in small laboratory animals, but has limitations associated with nonuniform spatial resolution or axial blurring. We have hypothesised that this blurring is due to incompleteness of the projection data acquired by a single circular pinhole orbit, and have evaluated a new strategy for accurate image reconstruction with better spatial resolution uniformity. A pinhole SPECT system using two circular orbits and a dedicated three-dimensional ordered subsets expectation maximisation (3D-OSEM) reconstruction method were developed. In this system, not the camera but the object rotates, and the two orbits are at 90degrees and 45degrees relative to the object's axis. This system satisfies Tuy's condition, and is thus able to provide complete data for 3D pinhole SPECT reconstruction within the whole field of view (FOV). To evaluate this system, a series of experiments was carried out using a multiple-disk phantom filled with Tc-99m solution. The feasibility of the proposed method for small animal imaging was tested with a mouse bone study using Tc-99m-hydroxymethylene diphosphonate. Feldkamp's filtered back-projection (FBP) method and the 3D-OSEM method were applied to these data sets, and the visual and statistical properties were examined. Axial blurring, which was still visible at the edge of the FOV even after applying the conventional 3D-OSEM instead of FBP for single-orbit data, was not visible after application of 3D-OSEM using two-orbit data. 3D-OSEM using two-orbit data dramatically reduced the resolution non-uniformity and statistical noise, and also demonstrated considerably better image quality in the mouse scan. This system may be of use in quantitative assessment of biophysiological functions in small animals.
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