DocumentCode :
322819
Title :
A rotating parallel hole collimator for high resolution imaging of medium energy radionuclides
Author :
Smith, Mark F. ; Jaszczak, Ronald J.
Author_Institution :
Dept. of Radiol., Duke Univ. Med. Center, Durham, NC, USA
Volume :
2
fYear :
1997
fDate :
9-15 Nov 1997
Firstpage :
1018
Abstract :
A novel rotating parallel hole collimator has been designed and built for high resolution imaging of medium energy radionuclides. The collimator has thick septa and was designed for imaging 50-100 mCi I-131 radiolabeled monoclonal antibodies being administered intratumorally for brain tumor therapy. Projection data from different collimator rotation positions are summed to create a composite projection dataset with more dense spatial sampling than projection data at a single position. Measured SPECT resolution with I-131 was 5.5-7.5 mm FWHM for a 13 cm radius of rotation compared with 9.9-13.9 mm with a conventional medium energy collimator. SPECT resolution for the rotating collimator was only slightly greater with I-131 than with Tc-99m, indicating good attenuation by the septa. Sensitivity was 56 counts/sec/mCi, as determined with a tight region of interest around the projection of an I-131 line source 12 cm from the collimator surface. SPECT studies of 3.7 cm and 6.2 cm diameter shell-core tumor phantoms filled with I-131 were made. The lower activity core and higher activity shell were well resolved in a SPECT study using the rotating hole collimator. SPECT shell to core activity concentration ratios were more accurate with the rotating collimator than with a medium energy collimator. These results show the potential of this rotating collimator for high resolution human tumor studies with I-131 tracers
Keywords :
biomedical equipment; image resolution; single photon emission computed tomography; 0.05 to 0.1 ci; 12 cm; 13 cm; 3.7 cm; 6.2 cm; I; I-131; I-131 radiolabeled monoclonal antibodies; I-131 tracers; collimator surface; conventional medium energy collimator; high resolution human tumor studies; high resolution imaging; higher activity shell; lower activity core; measured SPECT resolution; medical diagnostic imaging; medical instrumentation; medium energy radionuclides; nuclear medicine; region of interest; rotating parallel hole collimator; thick septa; Attenuation; Collimators; Energy measurement; Energy resolution; High-resolution imaging; Medical treatment; Neoplasms; Rotation measurement; Sampling methods; Spatial resolution;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Nuclear Science Symposium, 1997. IEEE
Conference_Location :
Albuquerque, NM
ISSN :
1082-3654
Print_ISBN :
0-7803-4258-5
Type :
conf
DOI :
10.1109/NSSMIC.1997.670483
Filename :
670483
Link To Document :
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