TY - GEN
T1 - Multi-centre assessment of HRRT image uniformity via 68Ge and 18F cylindrical and anthropomorphic phantoms
AU - Reader, Andrew J.
AU - Tahaei, Marzieh S.
AU - Rahmim, Arman
AU - Keller, Sune H.
AU - Blinder, Stephan
AU - Sibomana, Merence
AU - Soucy, Jean Paul
PY - 2013
Y1 - 2013
N2 - To date, the high resolution research tomograph (HRRT) still offers the highest resolution PET imaging capability of the human brain. Spatial uniformity of the images is of paramount importance, as many radioligand studies require either accurate regional dynamic quantification or, at the very least, accurate measurement of relative activities between regions. Often uniform cylinders, of 68Ge or 18F, are used for quality control and calibration purposes. This work examines the spatial uniformity obtained in reconstructed images of uniform cylinders from seven different HRRT centres, using either 68Ge or 18F, and also considering a head and brain phantom filled with 18F scanned at three of the centres. To account for varying activity levels used in each centre's data acquisition, and possibly different image reconstruction parameters, a progressive smoothing method was used to analyze image uniformity, with metrics designed to assess non-uniformity in image planes as well as in randomly selected region of interest pairs. Unusually high image non-uniformities were found for germanium cylinders at two centres, but of greater concern was the fact that uniformity for the brain phantom was found to be notably inferior at two of the three centres which scanned the phantom. A change of mumap reconstruction parameters, and minor adjustment of a parameter used in the single scatter simulation, was shown to remedy the issue (reducing relative region errors to <5%).
AB - To date, the high resolution research tomograph (HRRT) still offers the highest resolution PET imaging capability of the human brain. Spatial uniformity of the images is of paramount importance, as many radioligand studies require either accurate regional dynamic quantification or, at the very least, accurate measurement of relative activities between regions. Often uniform cylinders, of 68Ge or 18F, are used for quality control and calibration purposes. This work examines the spatial uniformity obtained in reconstructed images of uniform cylinders from seven different HRRT centres, using either 68Ge or 18F, and also considering a head and brain phantom filled with 18F scanned at three of the centres. To account for varying activity levels used in each centre's data acquisition, and possibly different image reconstruction parameters, a progressive smoothing method was used to analyze image uniformity, with metrics designed to assess non-uniformity in image planes as well as in randomly selected region of interest pairs. Unusually high image non-uniformities were found for germanium cylinders at two centres, but of greater concern was the fact that uniformity for the brain phantom was found to be notably inferior at two of the three centres which scanned the phantom. A change of mumap reconstruction parameters, and minor adjustment of a parameter used in the single scatter simulation, was shown to remedy the issue (reducing relative region errors to <5%).
UR - http://www.scopus.com/inward/record.url?scp=84904209256&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84904209256&partnerID=8YFLogxK
U2 - 10.1109/NSSMIC.2013.6829403
DO - 10.1109/NSSMIC.2013.6829403
M3 - Conference contribution
AN - SCOPUS:84904209256
SN - 9781479905348
T3 - IEEE Nuclear Science Symposium Conference Record
BT - 2013 IEEE Nuclear Science Symposium and Medical Imaging Conference, NSS/MIC 2013
PB - Institute of Electrical and Electronics Engineers Inc.
T2 - 2013 60th IEEE Nuclear Science Symposium and Medical Imaging Conference, NSS/MIC 2013
Y2 - 27 October 2013 through 2 November 2013
ER -