Body contour 180 degrees pinhole SPET with or without tilted detector: a phantom study.
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.
Seret
Alain
A
Imagerie médicale expérimentale et Centre de Recherche du Cyclotron, Institut de Physique, Université de Liège, Liège 1, Belgium. aseret@ulg.ac.be
Flérès
David
D
Firket
Olivier
O
Defrise
Michel
M
D000465:Algorithms; D005240:Feasibility Studies; D015902:Gamma Cameras; D007089:Image Enhancement / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D019047:Phantoms, Imaging; D011786:Quality Control; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D015899:Tomography, Emission-Computed, Single-Photon / Q000295:instrumentation* / Q000379:methods*