試題詳解

72.PET系統偵測到的訊號包括true coincidence、random coincidence及scatter coincidence，其中對於random coincidence rate的定義何者正確？（假設每一支detector的偵測效率皆相同，R_s：single channel noncoincidence rate, R_t：random coincidence count rate, t：coincidence resolving time）
(A)R_t=2×t×R_s
(B)R_t=2×t×R_s×R_s
(C)R_s=2×t×R_t
(D)R_s=2×t×R_t×R_t