Return to search

The origin of the "Block effect" which blurs images in positron emission tomography /

Commercial positron emission tomography scanners that use block detectors have additional blurring on spatial resolution, referred to as block effect. We studied the origin of the block effect, using experiments in which all other blurring effects were minimized and precisely determined. Bismuth germanate crystals (1 mm width) and a small (1 mm) 68Ge source were used to probe the spatial resolution of a CTI HR+ block detector and two precise translation stages to move detectors. Coincidence aperture functions for crystals in the block and for single crystals were compared. The central crystals in the block showed an additional blurring of 0.8 mm whereas the edge ones showed no additional blurring. The apparent centroids of the crystals in the block are not located at the geometric centers, which gives errors in the reconstruction algorithm assumed uniform sampling. Our results suggest that the additional blurring in scanners with block detectors is not only due to the use of block detectors.

Identiferoai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.80887
Date January 2003
CreatorsTomic, Nada
ContributorsThompson, Cristopher (advisor)
PublisherMcGill University
Source SetsLibrary and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada
LanguageEnglish
Detected LanguageEnglish
TypeElectronic Thesis or Dissertation
Formatapplication/pdf
CoverageMaster of Science (Department of Medical Radiation Physics.)
RightsAll items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated.
Relationalephsysno: 002031540, proquestno: AAIMQ98752, Theses scanned by UMI/ProQuest.

Page generated in 0.0016 seconds