title: Experimental assessment of resolution improvement of a zoom-in PET.
abstract: We have proposed a zoom-in positron emission tomography (PET) system that incorporates a high-resolution detector into an existing PET scanner to obtain high-resolution images of a region of interest. Previously we have shown by computer simulations that the high-resolution detector can improve the overall system performance in terms of spatial resolution and lesion detectability. In this study, we assessed the resolution improvement in a real system by incorporating a high-resolution detector into our existing microPET II scanner. The high-resolution detector consists of a 14 × 28 array of 0.5 × 0.5 × 10 mm³ lutetium oxyorthosilicate scintillator elements and is placed near the center of the microPET II scanner. It is coupled to two 64-channel photomultiplier tubes (PMTs) via tapered optical fiber bundles. The PMT signals were read out by the electronics in the microPET II scanner. A 15 µCi Na-22 point source was positioned at various locations above the high-resolution detector. Images were reconstructed using the data measured by the microPET II scanner alone and the microPET II data combined with the high-resolution detector data. Profiles taken through the reconstructed point sources show substantial reduction in full-width-at-half-maximum along the direction parallel to the face of the high-resolution detector.
authors.affiliation: Department of Biomedical Engineering, University of California, Davis, CA 95616, USA. qi@ucdavis.edu
authors.forename: Jinyi
authors.initials: J
authors.lastname: Qi
authors.forename: Yongfeng
authors.initials: Y
authors.lastname: Yang
authors.forename: Jian
authors.initials: J
authors.lastname: Zhou
authors.forename: Yibao
authors.initials: Y
authors.lastname: Wu
authors.forename: Simon R
authors.initials: SR
authors.lastname: Cherry
mesh_terms: D003952:Diagnostic Imaging; D004867:Equipment Design; D007089:Image Enhancement / Q000379:methods*; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008187:Lutetium / Q000737:chemistry; D019047:Phantoms, Imaging; D049268:Positron-Emission Tomography / Q000295:instrumentation* / Q000379:methods; D015203:Reproducibility of Results; D012588:Scintillation Counting / Q000379:methods*; D012680:Sensitivity and Specificity; D017640:Silicates / Q000737:chemistry; D014055:Tomography, Emission-Computed / Q000379:methods
chemical_list: D017640:Silicates; C477682:lutetium orthosilicate; D008187:Lutetium