Title :
Correction for emission contamination in transmission scans for the High Resolution Research Tomograph
Author :
De Jong, Hugo W A M ; Boellaard, Ronald ; Lenox, Mark ; Michel, Christiaan ; Lammertsma, Adriaan A.
Author_Institution :
Clinical PET Center, VU Med. Center, Amsterdam, Netherlands
Abstract :
The High Resolution Research Tomograph PET scanner is equipped with a moving Cs-137 transmission point source emitting 662 keV single photons. During postinjection transmission imaging 511 keV emission photons can be detected in the transmission window leading to gross underestimation of the reconstructed mu-value. Using cylindrical phantoms, methods to compensate for this emission contamination (EC) were investigated including histogram-based scaling and segmentation with varying transmission window settings. Furthermore, the effects of subtracting a uniform or nonuniform EC estimation prior to transmission reconstruction were quantified. In conclusion, EC during HRRT transmission scans can lead to gross underestimation of mu-values, and the most accurate way to compensate for this is to combine nonuniform EC subtraction with image segmentation.
Keywords :
caesium; gamma-ray detection; image reconstruction; image scanners; image segmentation; phantoms; positron emission tomography; single photon emission computed tomography; Cs; HRRT; High Resolution Research Tomograph PET scanner; cylindrical phantoms; emission contamination correction; emission photon detection; histogram-based scaling; image segmentation; moving Cs-137 transmission point source; postinjection transmission imaging; reconstructed mu-value; single photons; transmission scans; transmission window; Attenuation; Contamination; Detectors; Electromagnetic scattering; Energy resolution; Image reconstruction; Image segmentation; Imaging phantoms; Particle scattering; Positron emission tomography;
Conference_Titel :
Nuclear Science Symposium Conference Record, 2003 IEEE
Print_ISBN :
0-7803-8257-9
DOI :
10.1109/NSSMIC.2003.1352486
