Influence of malfunctioning block detectors on the calculation of single detector efficiencies in PET
- Service Hospitalier Frederic Joliot, Orsay (France)
- CTI PET Systems, Inc., Knoxville, TN (United States)
In this work, the authors studied the artifacts generated by the application of methods of crystal efficiency calculation based on the fan-sum, to situations of high variability of efficiency, namely the cases of a ring with defective blocks and acquisitions using narrow energy windows. They propose two efficiency calculation methods to reduce these artifacts: one method discriminates the crystals with an efficiency very different from the average, and then uses a modification of the fan-sum to estimate the efficiency; the other method calculates iteratively the fan-sum of each crystal, weighted by the efficiencies of the opposed detectors. The effect of using an off-center uniform cylinder is also discussed, since it influences the performance of the algorithms. The proposed algorithms are compared with the more conventional fan-sum method and with an algorithm used in a commercial tomography, using measurements and simulations. The results show a significant reduction of the efficiency estimation errors, in severe situations where detectors in a ring have very different detection efficiency.
- OSTI ID:
- 687369
- Report Number(s):
- CONF-981110-; ISSN 0018-9499; TRN: 99:010345
- Journal Information:
- IEEE Transactions on Nuclear Science, Vol. 46, Issue 4Pt2; Conference: 1998 IEEE nuclear science symposium and medical imaging conference, Toronto (Canada), 10-12 Nov 1998; Other Information: PBD: Aug 1999
- Country of Publication:
- United States
- Language:
- English
Similar Records
An investigation of factors affecting detector and geometric correction in normalization of 3-D PET data
A nonlinear lag correction algorithm for a-Si flat-panel x-ray detectors