Title :
Parallax correction in PET using depth of interaction information
Author :
MacDonald, Lawrence R. ; Dahlbom, Magnus
Author_Institution :
Div. of Nucl. Med., California Univ., Los Angeles, CA, USA
Abstract :
The authors have investigated the restoration of radial resolution for transaxially off-center sources in a PET ring detector configuration using directly measured depth of interaction (DOI) information. Lutetium oxyorthosilicate (LSO) crystals are coupled to a photodetector along the radial dimension of the PET ring configuration. Four millimeter wide crystals are segmented into 4 mm and 10 mm lengths in the radial dimension and optically isolated so that scintillation light is localized to the radial extent of the segment, giving 4 mm and 10 mm DOI resolution. The authors also segmented 2 mm wide crystals into 10 mm lengths. This DOI technique is unambiguous but not practical for a multi-ring PET scanner. The objective here is to quantify the intrinsic radial resolution as a function of position within the FOV and DOI resolution. The authors found the degradation in radial resolution across 75% of the field of view was reduced by 45% (50%) with DOI resolution equal to one-half (one-third) the crystal length. Improved resolution via narrower crystals and worse resolution due to non-colinearity were both overshadowed by DOI effects at 75% off-center positions in 30 mm deep crystals with 10 mm of DOI resolution
Keywords :
image resolution; medical image processing; positron emission tomography; 10 mm; 2 mm; 30 mm; 4 mm; PET ring detector configuration; depth of interaction information; lutetium oxyorthosilicate crystals; medical diagnostic imaging; nuclear medicine; photodetector; radial dimension; scintillation light localization; transaxially off-center sources; Biomedical optical imaging; Couplings; Nuclear measurements; Nuclear medicine; Photodetectors; Photonic crystals; Positron emission tomography; Solid scintillation detectors; Spatial resolution; USA Councils;
Conference_Titel :
Nuclear Science Symposium, 1997. IEEE
Conference_Location :
Albuquerque, NM
Print_ISBN :
0-7803-4258-5
DOI :
10.1109/NSSMIC.1997.670625