References of "Defrise, Michel"
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See detailBody contour 180 degrees pinhole SPET with or without tilted detector: a phantom study
Seret, Alain ULg; Flérès, David; Firket, Olivier et al

in European Journal of Nuclear Medicine and Molecular Imaging (2003), 30(9), 1205-1210

This study investigated the feasibility of ordered subsets expectation maximisation (OS-EM) reconstruction of 180 degrees pinhole single-photon emission tomography (SPET) acquired in body contour mode ... [more ▼]

This study investigated the feasibility of ordered subsets expectation maximisation (OS-EM) reconstruction of 180 degrees pinhole single-photon emission tomography (SPET) acquired in body contour mode (variable distance between the detector and the axis of rotation for each projection) with or without a tilted detector head. Four non-circular orbits were designed bearing in mind the rotation radius and tilt angle values of previous pinhole SPET acquisitions in patients with circular orbits. The reconstructions were performed using a dedicated OS-EM algorithm. Reconstructed images of line and uniformity phantoms showed that the spatial and uniformity characteristics of the radioactive objects were preserved. In comparison with the circular orbits, the non-circular orbits allowed only a moderate gain (maximum 10%) in resolution. However, body contour pinhole SPET would significantly facilitate the camera set-up and in this way should decrease the camera set-up time, which is an important parameter in patient studies. [less ▲]

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Peer Reviewed
See detail180 degrees Pinhole SPET with a tilted detector and OS-EM reconstruction: phantom studies and potential clinical applications
Seret, Alain ULg; Defrise, Michel ULg; Blocklet, Didier

in European Journal of Nuclear Medicine (2001), 28(12), 1836-1841

This study investigated the feasibility of ordered subsets expectation maximisation (OS-EM) reconstruction of pinhole single-photon emission tomography (SPET) acquired with a tilted detector head and a ... [more ▼]

This study investigated the feasibility of ordered subsets expectation maximisation (OS-EM) reconstruction of pinhole single-photon emission tomography (SPET) acquired with a tilted detector head and a 180 degrees orbit. Phantom and patient data were recorded using a standard single-head camera. Reconstructions were performed using a dedicated OS-EM algorithm. Reconstructed images of line, uniformity and Picker's thyroid phantoms showed that the geometry, physical size and uniformity of the radioactive objects were preserved. For the range of radius corresponding to the patient studies, the measured full-widths at half-maximum lay between 4.90+/-0.25 mm and 6.05+/-0.25 mm. Finally, the gain in resolution associated with the use of the pinhole collimator instead of a parallel-hole collimator was highlighted in a parathyroid exploration and in a shoulder bone study. [less ▲]

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