[Gate-users] Why there are so many trues in the boundary projection bins?

[Jinxia Guo]

Hi  gate users,

I simulate a single ring PET system whose ring diameter is about 80cm and
there are 400 LSO crystals in the ring. A cylinder phantom whose diameter is
27cm is placed in the center of the system. Coincidences in all the
projection bins are counted. I found there are plenty of true coincidences
in the projection bins that is near the boundary of the PET ring. See the
attached picture.Where these counts come from? Could some one know the
reason? Thanks for help!

Regards,
Jinxia Guo

-- 
Jinxia Guo
School of Life Sci&Tech
D11 Building Room 503

Huazhong Univ. of Sci. & Tech

1037 Luoyu Road, Wuhan 430074, China
Tel:+86-27-8779-2294
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