DocumentCode :
3340184
Title :
Evaluation of image based spatially variant and count rate dependant point spread functions on the HRRT PET scanner
Author :
Kotasidis, Fotis A. ; Angelis, Georgios I. ; Henderson, Jack ; Buckley, Anna ; Markiewicz, Pawel J. ; Green, Michael ; Anton-Rodriguez, Jose ; Lionheart, William R. ; Reader, Andrew J. ; Matthews, Julian C.
Author_Institution :
Sch. of Cancer & Enabling Sci., Univ. of Manchester, Manchester, UK
fYear :
2011
fDate :
23-29 Oct. 2011
Firstpage :
3595
Lastpage :
3596
Abstract :
Spatial resolution is of high importance especially in preclinical and brain PET imaging and characterization of the scanner´s resolution properties requires measuring its point spread function (PSF). In our previous work we measured the PSF in 2 PET/CT scanners using a printed point source array. Here we extend the work to accurately measure the spatial variation of the PSF on the High Resolution Research Tomograph (HRRT) and assess the impact of the scanner´s depth of interaction (DOI) capability on the spatial resolution. Furthermore we characterize the dependency of the PSF to count rate. An array of 15×11 printed sources was scanned twice, initially on its own (10min scan) and subsequently with an extension line containing ~300MBq of carbon-11 at the scan starts (15 × 10min contiguous frames). Data were reconstructed with OP-OSEM and invariant PSF OP-OSEM. The PSF was found to be radially dependent in all directions but importantly radially symmetric and almost axially independent. The FWHM improves by ~1.3mm using the PSF-OP-OSEM but is still radially variable with almost 1 mm degradation within the boundaries within which the brain is typically located. When DOI was not taken into account, a degradation up to 0.7mm was seen in the radial FWHM. In terms of count rate dependency, a clear resolution deterioration was seen, for count rates above 5-10 kcps with such count rates observed during many clinical scans.
Keywords :
brain; computerised tomography; medical image processing; neurophysiology; optical transfer function; positron emission tomography; HRRT PET scanner; PET-CT scanners; brain PET imaging; count rate dependant point spread functions; high resolution research tomography; image based spatially variant evaluation; preclinical imaging; printed point source array; radial FWHM; spatial resolution; Degradation; Image resolution; Positron emission tomography;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC), 2011 IEEE
Conference_Location :
Valencia
ISSN :
1082-3654
Print_ISBN :
978-1-4673-0118-3
Type :
conf
DOI :
10.1109/NSSMIC.2011.6153675
Filename :
6153675
Link To Document :
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