RT Journal Article
SR Electronic
T1 Evaluation of collimator blurring, attenuation, and scatter corrections for brain SPECT
JF Journal of Nuclear Medicine
JO J Nucl Med
FD Society of Nuclear Medicine
SP 1504
OP 1504
VO 50
IS supplement 2
A1 T Zeniya
A1 T Sakimoto
A1 K Ishida
A1 H Watabe
A1 Y Hirano
A1 A Sohlberg
A1 K Minato
A1 H Iida
YR 2009
UL http://jnm.snmjournals.org/content/50/supplement_2/1504.abstract
AB 1504 Objectives The quality of SPECT image is hampered by collimator blurring, attenuation and scatter. We implemented 3D-OSEM reconstruction method with collimator blurring correction (CBC), attenuation correction (AC) and scatter correction (SC). Monte Carlo-based scatter correction method was employed for more accurate correction. This reconstruction was evaluated only in simulation. The aim of this study was to more realistically evaluate these corrections for brain SPECT in phantom experiments. Methods Collimator blurring was modeled by depth-dependent response function assumed to be Gaussian. Attenuation map was generated by setting uniform coefficient (0.167/cm) inside the contour of the emission image. Resolution was measured using line source with Tc-99m. Brain phantom with Tc-99m was scanned to evaluate resolution and contrast. Projection data were acquired by Toshiba GCA7200A with LEHR parallel collimator and 130-mm radius of rotation, and reconstructed using OSEM without correction, with CBC, with CBC+AC, and with CBC+AC+SC. The reconstructed images were compared visually and by contrast of hot to cold regions. Results The CBC significantly improved resolution from 9 mm to 5 mm. From results of brain phantom study, the CBC improved not only resolution but also noise property. Although only AC overcorrected the reconstructed image, AC and SC reduced overcorrection and improved the contrast. The contrasts were 1.81 for non-correction, 2.62 for CBC, 3.84 for CBC+AC, and 7.65 for CBC+AC+SC. Conclusions This phantom study validated that our reconstruction method with collimator blurring, attenuation and scatter corrections improve resolution, noise property and contrast for brain SPECT.